Schizoid personality disorder
Schizoid personality disorder (/ˈskɪtsɔɪd, ˈskɪdzɔɪd, ˈskɪzɔɪd/, often abbreviated as SzPD or ScPD) is a personality disorder characterized by a lack of interest in social relationships, a tendency toward a solitary or sheltered lifestyle, secretiveness, emotional coldness, detachment and apathy. Affected individuals may be unable to form intimate attachments to others and simultaneously possess a rich and elaborate but exclusively internal fantasy world.[6][12] Other associated features include stilted speech, a lack of deriving enjoyment from most activities, feeling as though one is an "observer" rather than a participant in life, an inability to tolerate emotional expectations of others, apparent indifference when praised or criticized, a degree of asexuality, and idiosyncratic moral or political beliefs.[13] Symptoms typically start in late childhood or adolescence.[6]
Schizoid personality disorder | |
---|---|
People with schizoid personality disorder often prefer solitary activities. | |
Pronunciation |
|
Specialty | Psychiatry, clinical psychology |
Symptoms | Pervasive emotional detachment, reduced affect, lack of close friends, apathy, anhedonia, unintentional insensitivity to social norms, sexual abstinence, preoccupation with fantasy,[1] autistic thinking without loss of skill to recognize reality[2] |
Usual onset | Late childhood or adolescence[1] |
Duration | Long term |
Types | Languid schizoid, remote schizoid, depersonalized schizoid, affectless schizoid (Millon's subtypes)[3] |
Risk factors | Family history[4] |
Diagnostic method | Based on symptoms |
Differential diagnosis | Other mental disorders with psychotic symptoms (schizophrenia, delusional disorder, and a bipolar or depressive disorder with psychotic features), personality change due to another medical condition, substance use disorders, autism spectrum disorder, other personality disorders and personality traits[5] |
Treatment | Not yet studied.[6] |
Medication | Not general practice but may include low dose benzodiazepines, β-blockers, nefazodone, bupropion[7] |
Prognosis | Typically poor[8][9][10] |
Frequency | 0.8%[4][8][11] |
Personality disorders |
---|
Cluster A (odd) |
|
Cluster B (dramatic) |
Cluster C (anxious) |
Not otherwise specified |
Depressive |
Others |
|
The cause of SzPD is uncertain, but there is some evidence of links and shared genetic risk between SzPD, other cluster A personality disorders (such as schizotypal personality disorder) and schizophrenia. Thus, SzPD is considered to be a "schizophrenia-like personality disorder".[4][14] It is diagnosed by clinical observation, and it can be very difficult to distinguish SzPD from other mental disorders or conditions (such as autism spectrum disorders, with which it may sometimes overlap).[15][16]
The effectiveness of psychotherapeutic and pharmacological treatments for SzPD has yet to be empirically and systematically investigated. There is little clinical data on SzPD because it is rarely encountered in clinical settings.[6] It is not general practice to treat SzPD with medications, other than for the short-term treatment of associated disorders such as depression or anhedonia.[17][7] Talk therapies such as cognitive behavioral therapy (CBT) may not be effective, because people with SzPD may have a hard time forming a good working relationship with a therapist.[6]
SzPD is a poorly studied disorder. Studies have generally reported a prevalence of less than 1%.[4][11][5] It is more commonly diagnosed in males than in females.[11] SzPD is linked to negative outcomes, including a significantly compromised quality of life, reduced overall functioning even after 15 years and one of the lowest levels of "life success" of all personality disorders (measured as "status, wealth and successful relationships").[8][9][10] Bullying is particularly common towards schizoid individuals.[3][18] Suicide may be a running mental theme for schizoid individuals, though they are not likely to actually attempt it.[19] Some symptoms of SzPD (e.g. solitary lifestyle, emotional detachment, loneliness, and impaired communication), however, have been stated as general risk factors for serious suicidal behaviour.[20][21]
Signs and symptoms
People with SzPD are often aloof, cold and indifferent, which causes interpersonal difficulty. Most individuals diagnosed with SzPD have trouble establishing personal relationships or expressing their feelings meaningfully. They may remain passive in the face of unfavorable situations. Their communication with other people may be indifferent and terse at times. Schizoid personality types often lack the ability to assess the impact of their own actions in social situations.[22] According to Guntrip, Klein and others, people with SzPD may possess a hidden sense of superiority and lack dependence on other people's opinions.
Aaron Beck and his colleagues report that people with SzPD seem comfortable with their aloof lifestyle and consider themselves observers, rather than participants in the world around them. But they also mention that many of their schizoid patients recognize themselves as socially deviant (or even defective) when confronted with the different lives of ordinary people – especially when they read books or see movies focusing on relationships. Even when schizoid individuals may not long for closeness, they can become weary of being "on the outside, looking in". These feelings may lead to depression or depersonalization. If they do, schizoid people often experience feeling "like a robot" or "going through life in a dream".[23] Although there is the belief that people with SzPD are complacent and unaware of their feelings, many recognize their differences from others. Some individuals in treatment say "life passes them by" or they feel like living inside a shell; they see themselves as "missing the bus" and speak of observing life from a distance.[24][25]
Relationships
People with SzPD tend to be happiest in relationships without the expectation of phatic or social niceties. It is not necessarily people they want to avoid, but negative or positive emotional expectations, emotional intimacy and self-disclosure.[26] Therefore, it is possible for individuals with SzPD to form relationships around intellectual, physical, familial, occupational or recreational activities, as long as there is no need for emotional intimacy. Donald Winnicott explains that this is because schizoid individuals "prefer to make relationships on their own terms and not in terms of the impulses of other people". Failing to attain that, they prefer isolation.[27] In general, friendship among schizoids is usually limited to one person, often also schizoid, forming what has been called a union of two eccentrics; "within it – the ecstatic cult of personality, outside it – everything is sharply rejected and despised".[28]
Ronald Fairbairn notes that schizoids can fear that in a relationship, their needs will weaken and exhaust their partner, so they feel forced to disown them and move to satisfy solely the needs of the partner. The net result of this is a loss of dignity and sense of self within any relationship they enter, eventually leading to intolerable frustration and friction. Appel notes that these fears result in the schizoid's negativism, stubbornness and reluctance to love. Thus, a central conflict of the schizoid is between an immense longing for relationships but a deep anxiety and avoidance of relationships, manifested by choosing to abandon others as the "lesser evil".[29]: 100 A person with SzPD may feel suffocated when their personal space is violated and take actions to avoid this feeling.
Secret schizoids
Many schizoid individuals display an engaging, interactive personality, contradicting the observable characteristic emphasized by the DSM-5 and ICD-10 definitions of the schizoid personality. Guntrip (using ideas of Klein, Fairbairn and Winnicott) classifies these individuals as "secret schizoids", who behave with socially available, interested, engaged and involved interaction yet remain emotionally withdrawn and sequestered within the safety of the internal world.[19]: 17 [30] Klein distinguishes between a "classic" SzPD and a "secret" SzPD, which occur "just as often" as each other. Klein cautions one should not misidentify the schizoid person as a result of the patient's defensive, compensatory interaction with the external world. He suggests one ask the person what their subjective experience is, to detect the presence of the schizoid refusal of emotional intimacy and preference for objective fact.[19]
Frequently, a schizoid individual's social functioning improves, sometimes dramatically, when the individual knows they are an anonymous participant in a real-time conversation or correspondence, e.g. in an online chatroom or message board. It is often the case the individual's online correspondent will report nothing amiss in the individual's engagement and affect. A 2013 study looking at personality disorders and Internet use found that being online more hours per day predicted signs of SzPD. Additionally, SzPD correlated with lower phone call use and fewer Facebook friends.[31]
Descriptions of the schizoid personality as "hidden" behind an outward appearance of emotional engagement have been recognized since 1940, with Fairbairn's description of "schizoid exhibitionism", in which the schizoid individual is able to express a great deal of feeling and to make what appear to be impressive social contacts yet in reality gives nothing and loses nothing. Because they are "playing a part", their personality is not involved. According to Fairbairn, the person disowns the part they are playing, and the schizoid individual seeks to preserve their personality intact and immune from compromise.[32] The schizoid's false persona is based around what those around them define as normal or good behaviour, as a form of compliance.[29]: 143 Further references to the secret schizoid come from Masud Khan,[33] Jeffrey Seinfeld[34] and Philip Manfield,[26] who give a description of an SzPD individual who "enjoys" public speaking engagements but experiences great difficulty in the breaks when audience members would attempt to engage him emotionally. These references expose the problems in relying on outer observable behavior for assessing the presence of personality disorders in certain individuals.
Schizoid fantasy
A pathological reliance on fantasizing and preoccupation with inner experience is often part of the schizoid withdrawal from the world. Fantasy thus becomes a core component of the self in exile, though fantasizing in schizoid individuals is far more complicated than a means of facilitating withdrawal.[19]: 64 The related schizotypal personality disorder and schizophrenia are reported to have ties to creative thinking, and it is speculated that the internal fantasy aspect of SzPD may also be reflective of this thinking.[35][36][37]
Fantasy is also a relationship with the world and with others by proxy. It is a substitute relationship, but a relationship nonetheless, characterized by idealized, defensive and compensatory mechanisms. This is self-contained and free from the dangers and anxieties associated with emotional connection to real persons and situations.[19] Klein explains it as "an expression of the self struggling to connect to objects, albeit internal objects. Fantasy permits schizoid patients to feel connected, and yet still free from the imprisonment in relationships. In short, in fantasy one can be attached (to internal objects) and still be free."[19] This aspect of schizoid pathology has been generously elaborated in works by R. D. Laing,[22] Donald Winnicott[38] and Ralph Klein.[19]: 64
Sexuality
People with SzPD are sometimes sexually apathetic, though they do not typically experience anorgasmia. Their preference to remain alone and detached may cause their need for sex to appear to be less than that of those who do not have SzPD. The schizoid is often labelled asexual or presents with "a lack of sexual identity". Kernberg states that this apparent lack of a sexuality does not represent a lack of sexual definition but rather a combination of several strong fixations to cope with the same conflicts.[29]: 125 Significantly broadening this picture are notable exceptions of SzPD individuals who engage in occasional or even frequent sexual activities with others.[39]
Sex often causes individuals with SzPD to feel that their personal space is being violated, and they commonly feel that masturbation or sexual abstinence is preferable to the emotional closeness that they must tolerate when having sex.[39] Individuals with SzPD have long been noted to have an increased rate of unconventional sexual tendencies, though if present, these are rarely acted upon. People with SzPD are often able to pursue any fantasies with content on the Internet while remaining completely unengaged with the outside world.[29]: 127
Akhtar's profile
Salman Akhtar provided a comprehensive phenomenological profile of SzPD in which classic and contemporary descriptive views are synthesized with psychoanalytic observations. Akhtar states that his profile has several advantages over the DSM in terms of maintaining historical continuity of the use of the word schizoid, valuing depth and complexity over descriptive oversimplification and helping to provide a more meaningful differential diagnosis of SzPD from other personality disorders.[13]
This profile is summarized in the table reproduced below that lists clinical features that involve six areas of psychosocial functioning and are organized by "overt" and "covert" manifestations, intended to denote seemingly contradictory aspects that may simultaneously be present in an individual.[13] These designations do not necessarily imply their conscious or unconscious existence. The covert characteristics are not immediately apparent by definition and difficult to discern. Additionally, the lack of data on the frequency of many of the features makes their relative diagnostic weight difficult to distinguish at this time.
Area | ||
---|---|---|
Overt characteristics | Covert characteristics | |
Self-concept |
|
|
Interpersonal relations |
|
|
Social adaptation |
|
|
Love and sexuality |
|
|
Ethics, standards, and ideals |
|
|
Cognitive style |
|
|
Millon's subtypes
Theodore Millon restricted the term "schizoid" to those personalities who lack the capacity to form social relationships. He characterizes their way of thinking as being vague and void of thoughts and as sometimes having a "defective perceptual scanning". Because they often do not perceive cues that trigger affective responses, they experience fewer emotional reactions.[23][40]
For Millon, SzPD is distinguished from other personality disorders in that it is "the personality disorder that lacks a personality." He criticizes that this may be due to the current diagnostic criteria: They describe SzPD only by an absence of certain traits, which results in a "deficit syndrome" or "vacuum". Instead of delineating the presence of something, they mention solely what is lacking. Therefore, it is hard to describe and research such a concept.[3]
He identified four subtypes of SzPD. Any individual schizoid may exhibit none or one of the following:[3][41]
Subtype | Features |
---|---|
Languid schizoid (including dependent and depressive features) | Marked inertia; deficient activation level; intrinsically phlegmatic, lethargic, weary, leaden, lackadaisical, exhausted, enfeebled. Unable to act with spontaneity or seeks simplest pleasures, may experience profound angst, yet lack the vitality to express it strongly. |
Remote schizoid (including avoidant features) | Distant and removed; inaccessible, solitary, isolated, homeless, disconnected, secluded, aimlessly drifting; peripherally occupied. Seen among people who would have been otherwise capable of developing normal emotional life but having been subjected to intense hostility lost their innate capability to form bonds. Some residual anxiety is present. |
Depersonalized schizoid (including schizotypal features) | Disengaged from others and self; self is disembodied or distant object; body and mind sundered, cleaved, dissociated, disjoined, eliminated. Often seen as simply staring into the empty space or being occupied with something substantial while actually being occupied with nothing at all. |
Affectless schizoid (including compulsive features) | Passionless, unresponsive, unaffectionate, chilly, uncaring, unstirred, spiritless, lackluster, unexcitable, unperturbed, cold; all emotions diminished. Combines the preference for rigid schedule (obsessive-compulsive feature) with the coldness of the schizoid. |
Causes
Some evidence suggests the cluster A personality disorders have shared genetic and environmental risk factors, and there is an increased prevalence of SzPD in relatives of people with schizophrenia and schizotypal personality disorder.[4] Twin studies with SzPD traits (e.g. low sociability and low warmth) suggest these are inherited. Besides this indirect evidence, the direct heritability estimates of SzPD range from 50 to 59%.[42][43] To Sula Wolff, who did extensive research and clinical work with children and teenagers with schizoid symptoms, "schizoid personality has a constitutional, probably genetic, basis."[44] The link between SzPD and being underweight may also point to the involvement of biological factors.[3][45]
In general, prenatal caloric malnutrition, premature birth and a low birth weight are risk factors for having a mental disorder and may contribute to the development of SzPD as well. Those who have experienced traumatic brain injury may be also at risk of developing features reflective of SzPD.[46][47][48]
Other historical researchers had hypothesized excessively perfectionist,[49] unloving or neglectful parenting could play a role.
Diagnosis
DSM-5 criteria
The Diagnostic and Statistical Manual of Mental Disorders is a widely used manual for diagnosing mental disorders. DSM-5 includes SzPD with the same criteria as in DSM-IV. In the DSM-5, SzPD is described as a pervasive pattern of detachment from social relationships and a restricted range of expression of emotions in interpersonal settings, beginning by early adulthood and present in a variety of contexts, as indicated by at least four of the following:[5]
- Neither desires nor enjoys close relationships, including being part of a family.
- Almost always chooses solitary activities.
- Has little, if any, interest in having sexual experiences with another person.
- Takes pleasure in few, if any, activities.
- Lacks close friends or confidants other than first-degree relatives.
- Appears indifferent to the praise or criticism of others.
- Shows emotional coldness, detachment, or flattened affectivity.
According to the DSM, those with SzPD may often be unable to, or will rarely express aggressiveness or hostility, even when provoked directly. These individuals can seem vague or drifting about their goals and their lives may appear directionless. Others view them as indecisive in their actions, self-absorbed, absent-minded and detached from their surroundings. Excessive daydreaming is often present. In cases with severe defects in the capacity to form social relationships, dating and marriage may not be possible.[18]
ICD-10 criteria
The Classification of Mental and Behavioural Disorders of ICD-10 lists SzPD under (F60.1).[1]
The general criteria of personality disorder (F60) should be met first. In addition, at least four of the following criteria must be present:
- Few, if any, activities provide pleasure.
- Displays emotional coldness, detachment, or flattened affectivity.
- Limited capacity to express warm, tender feelings for others as well as anger.
- Appears indifferent to either praise or criticism from others.
- Little interest in having sexual experiences with another person (taking into account age).
- Almost always chooses solitary activities.
- Excessive preoccupation with fantasy and introspection.
- Neither desires, nor has, any close friends or confiding relationships (or only one).
- Marked insensitivity to prevailing social norms and conventions; if these are not followed, this is unintentional.
Guntrip criteria
Ralph Klein, Clinical Director of the Masterson Institute, delineates the following nine characteristics of the schizoid personality as described by Harry Guntrip:[19]: 13–23
- Introversion
- Withdrawnness
- Narcissism
- Self-sufficiency
- Sense of superiority
- Loss of affect
- Loneliness
- Depersonalization
- Regression
The description of Guntrip's nine characteristics should clarify some differences between the traditional DSM portrait of SzPD and the traditional informed object relations view. All nine characteristics are consistent. Most, if not all, must be present to diagnose a schizoid disorder.[19]
Differential diagnosis
While SzPD shares several symptoms with other mental disorders, there are some important differentiating features.
Psychological condition | Features |
---|---|
Depression | People who have SzPD may also have clinical depression. However, this is not always the case. Unlike people with depression, persons with SzPD generally do not consider themselves inferior to others. They may recognize instead that they are "different". |
Avoidant personality disorder | While people affected with avoidant personality disorder (AvPD) avoid social interactions due to anxiety or feelings of incompetence, those with SzPD do so because they are genuinely indifferent to social relationships. A 1989 study,[50] however, found that "schizoid and avoidant personalities were found to display equivalent levels of anxiety, depression, and psychotic tendencies as compared to psychiatric control patients." There also seems to be some shared genetic risk between SzPD and AvPD (see schizoid-avoidant behavior). Several sources have confirmed the synonymy of SzPD and avoidant attachment style.[51] However, the distinction should be made that individuals with SzPD characteristically do not seek social interactions merely due to lack of interest, while those with avoidant attachment style can in fact be interested in interacting with others but without establishing connections of much depth or length due to having little tolerance for any kind of intimacy. |
Narcissistic personality disorder | Schizoid and narcissistic personality disorders can seem similar in the presence of identity confusion, lack of warmth and spontaneity, and avoidance of deep relationships with intimacy. Another commonality observed by Akhtar is preferring ideas over people and displaying "intellectual hypertrophy" with a corresponding lack of rootedness in bodily existence. There are, nonetheless, important differences. The schizoid hides his need for dependency and is rather fatalistic, passive, cynical, overtly bland or vaguely mysterious. The narcissist is, in contrast, ambitious and competitive and exploits others for his dependency needs.
Sense of superiority in SzPD is very different from the grandiosity seen in narcissistic personality disorder, which is described as "burdened with envy" and with a desire to destroy or put down others. Additionally, schizoids do not go out of their way to achieve social validation.[29]: 60 Unlike the narcissist, the schizoid will often keep their creations private to avoid unwelcome attention or the feeling that their ideas and thoughts are being appropriated by the public.[29]: 174 |
Obsessive–compulsive personality disorder | There are also parallels between SzPD and obsessive–compulsive personality disorder (OCPD), such as detachment, restricted emotional expression and rigidity. However, in OCPD the capacity to develop intimate relationships is usually intact, but deep contacts may be avoided because of an unease with emotions and a devotion to work.[13][18] |
Asperger syndrome | There may be substantial difficulty in distinguishing Asperger syndrome (AS) from SzPD. But while AS is an autism spectrum disorder, SzPD is classified as a "schizophrenia-like" personality disorder. There is some overlap, as some people with autism also meet schizotypal or schizoid diagnostic criteria. However, one distinct feature of SzPD is a restricted affect and an impaired capacity for emotional experience and expression. Persons with AS are "hypo-mentalizers", i.e., they fail to recognize social cues such as verbal hints, body language and gesticulation, but those with schizophrenia-like personality disorders tend to be "hyper-mentalizers", overinterpreting such cues in a generally suspicious way.[52][53][54]
Although they may have been socially isolated from childhood onward, most people with SzPD displayed well-adapted social behavior as children, along with apparently normal emotional function. SzPD also does not require impairments in nonverbal communication such as a lack of eye contact, unusual prosody or a pattern of restricted interests or repetitive behaviors.[55] |
Simple-type schizophrenia | The simple-type schizophrenia diagnosis is present in the ICD-10 but not in the DSM-5 or the ICD-11.[56][57] It is characterised by negative symptoms without psychotic features. Both simple-type schizophrenia and SzPD share many negative symptoms like avolition, impoverished thinking and flat affect. Although they may look almost identical, what distinguishes them is usually the severity. Also, SzPD is characterized by a lifelong pattern without change, whereas simple-type schizophrenia represents a deterioration.[58] |
Comorbidity
SzPD is often found to be comorbid with several disorders or pathologies. Persons with SzPD may meet criteria for an additional personality disorder, most often avoidant personality disorder, schizotypal personality disorder or paranoid personality disorder.[24] Alexithymia (the inability to identify and describe emotions) is often present in SzPD.[59] Sharon Ekleberry suggests that some people with schizoid personality features may occasionally experience instances of brief reactive psychosis when under stress.[24]
Substance use disorder
Very little data exists for rates of substance use disorder among people with SzPD, but existing studies suggest they are less likely to have substance abuse problems than the general population. One study found that significantly fewer boys with SzPD had alcohol problems than a control group of non-schizoids.[60] Another study evaluating personality disorder profiles in substance abusers found that substance abusers who showed schizoid symptoms were more likely to abuse one substance rather than many, in contrast to other personality disorders such as borderline, antisocial or histrionic, which were more likely to abuse many.[61]
American psychotherapist Sharon Ekleberry states that the impoverished social connections experienced by people with SzPD limit their exposure to the drug culture and that they have limited inclination to learn how to do narcotics. Describing them as "highly resistant to influence", she additionally states that even if they could access illegal drugs, they would be disinclined to use them in public or social settings, and because they would be more likely to use alcohol or cannabis alone than for social disinhibition, they would not be particularly susceptible to negative consequences in early use.[24]
Suicide
Suicide may be a running theme for schizoid individuals, in part due to the knowledge of the large-scale ostracism that would result if their idiosyncratic views were revealed and their experience that most, if not all people, are unrelatable or have polar opposite reactions to them on societally sensitive issues, though they are not likely to actually attempt it. They might be down and depressed when all possible connections have been cut off, but as long as there is some relationship or even hope for one the risk will be low. The idea of suicide is a driving force against the person's schizoid defenses. Often among people with SzPD, there is a rationally grounded and reasoned position on why they want to die, and this "suicidal construct" takes a stable position in the mind.
The characteristics of the premorbidities (schizothymia, autism, anhedonia) also affected suicidal behaviour. Suicide attempts were always genuine in nature, well-planned, and it was only by chance that patients survived (usually the fatal outcome was prevented by the sudden appearance of others). They denied the existence of suicidal experiences earlier, but argued that in the current circumstances, suicide seemed to them the most appropriate way out. Important in all these cases was the absence of any significant anti-suicidal factors (most were found in a situation of relative social isolation; there were no professional and personal interests). The high ability to introspect in these cases only increased the isolation from reality, rendering the choice of suicide more reasonable.[62]
A mini-review indicates that SzPD or schizoid traits are a major risk factor for both suicide attempts and suicide,[21] but schizoids tend to hide their suicidal thoughts and intentions. Demonstrative suicides or suicide blackmail, as seen in cluster B personality disorders such as borderline, histrionic or antisocial, are extremely rare among schizoid individuals.[62] As in other clinical mental health settings, among suicidal inpatients, individuals with SzPD are not as well-represented as some other groups. A 2011 study on suicidal inpatients at a Moscow hospital found that schizoids were the least common patients, while those with cluster B personality disorders were the most common.[62]
Low weight
A study which looked at the body mass index (BMI) of a sample of both male adolescents diagnosed with SzPD and those diagnosed with Asperger syndrome found that the BMI of all patients was significantly below normal. Clinical records indicated abnormal eating behaviour by some patients. Some patients would only eat when alone and refused to eat out. Restrictive diets and fears of disease were also found. It was suggested that the anhedonia of SzPD may also cover eating, leading schizoid individuals to not enjoy it. Alternatively, it was suggested that schizoid individuals may not feel hunger as strongly as others or not respond to it, a certain withdrawal "from themselves".[3]
Anti-social conduct
Another study looked at rates of anti-social conduct in boys with either SzPD or Asperger syndrome compared with a control group of non-schizoid individuals and found the incidence of anti-social conduct to be the same in both groups. However, the schizoid boys stole significantly less. Upon follow-up in adulthood, out of a matched group of 19 boys with SzPD and 19 boys without, four of the schizoid boys reported having exclusively internal violent fantasies (concerned with Zulu wars, abattoirs, fascists and communists and a collection of knives, respectively), which were pursued entirely by themselves, while the only non-schizoid subject to report a violent fantasy life shared his with a group of young men (dressing up and riding motorcycles as a self-styled "panzer" group).[60]
An absent parent or socio-economic disadvantage did not seem to affect the risk of anti-social conduct in schizoid individuals as much as it did in non-schizoid individuals. Absent parents and parental socio-economic disadvantage were also less common in the schizoid group.[60]
Distinction from autism spectrum disorders
Several studies have reported an overlap with Asperger syndrome which had traditionally been called "schizoid disorder of childhood".[63][15][16][64] Eugen Bleuler coined both the terms "autism" and "schizoid" to describe withdrawal to an internal fantasy, against which any influence from outside becomes an intolerable disturbance.[65] Tantam suggested that Asperger syndrome may confer an increased risk of developing SzPD.[63]
A study from 2012 found that in a sample of 54 young adults with Asperger syndrome, 26% of them also met criteria for SzPD, the highest comorbidity out of any personality disorder in the sample (the other comorbidities were 19% for obsessive–compulsive personality disorder, 13% for avoidant personality disorder and one female with schizotypal personality disorder). Additionally, twice as many men with Asperger syndrome met criteria for SzPD than women. While 41% of the whole sample were unemployed with no occupation, this rose to 62% for the Asperger's and SzPD comorbid group.[15] It noted that the DSM may complicate diagnosis by requiring the exclusion of a pervasive developmental disorder (PDD) before establishing a diagnosis of SzPD. The study found that social interaction impairments, stereotyped behaviours and specific interests were more severe in the individuals with Asperger syndrome also fulfilling SzPD criteria, against the notion that social interaction skills are unimpaired in SzPD. The authors believe that a substantial subgroup of people with autism spectrum disorder or PDD have clear "schizoid traits" and correspond largely to the "loners" in Lorna Wing's classification The autism spectrum (Lancet 1997), described by Sula Wolff.[15]
A study from 2019 found that 54% of a group of males aged 11 to 25 with Asperger syndrome showed significant SzPD traits, with 6% meeting full diagnostic criteria for SzPD, compared to 0% of a control group.[16] The authors of the study hypothesised that it is extremely likely that historic cohorts of adults diagnosed with SzPD were either misdiagnosed, or they also had childhood-onset autistic syndromes. They stressed that further research to clarify overlap and distinctions between these two syndromes was strongly warranted, especially given that high-functioning autism spectrum disorders are now recognised in around 1% of the population.[66]
Treatment
People with SzPD rarely seek treatment for their condition. This issue is found in many personality disorders, which prevents many people with these conditions from seeking treatment: they tend to view their condition as not conflicting with their self-image and their abnormal perceptions and behaviors as rational and appropriate. There are little data on the effectiveness of various treatments on this personality disorder because it is seldom seen in clinical settings.[6][67]
Medication
No medications are indicated for directly treating SzPD, but certain medications may reduce the symptoms of SzPD and treat co-occurring mental disorders. However, it is not general practice to treat SzPD with medications, other than for the short-term treatment of acute co-occurring axis I conditions such as depression.[17] The substituted amphetamine bupropion may be used to treat anhedonia.[7] Lamotrigine, SSRIs, TCAs, MAOIs and hydroxyzine may help counter social anxiety if it is a concern for people who have SzPD.
The symptoms of SzPD mirror the negative symptoms of schizophrenia, such as anhedonia, blunted affect and low energy. SzPD is thought to be part of the "schizophrenia spectrum" of disorders, thus it may benefit from the medications that treat those disorders[17] such as modafinil.[68] Originally, low doses of atypical antipsychotics like risperidone or olanzapine were used to alleviate social deficits and blunted affect.[7] However, a 2012 review concluded that atypical antipsychotics were ineffective for treating personality disorders.[69]
Psychotherapy
Despite the relative emotional comfort, psychoanalytic therapy of schizoid individuals takes a long time and causes many difficulties.[70] Schizoids are generally poorly involved in psychotherapy due to difficulties in establishing empathic relations with a psychotherapist and low motivation for treatment.[71]
Supportive psychotherapy is used in an inpatient or outpatient setting by a trained professional that focuses on areas such as coping skills, improvement of social skills and social interactions, communication and self-esteem issues. People with SzPD may also have a perceptual tendency to miss subtle differences in expression. That causes an inability to pick up hints from the environment because social cues from others that might normally provoke an emotional response are not perceived. That in turn limits their own emotional experience.[23] The perception of varied events only increases their fear for intimacy and limits them in their interpersonal relationships. Their aloofness may limit their opportunities to refine the social skills and behavior necessary to effectively pursue relationships.
Besides psychodynamic therapy, cognitive behavioral therapy (CBT) can be used. But because CBT generally begins with identifying the automatic thoughts, one should be aware of the potential hazards that can happen when working with schizoid patients. People with SzPD seem to be distinguished from those with other personality disorders in that they often report having few or no automatic thoughts at all. That poverty of thought may have to do with their apathetic lifestyle. But another possible explanation could be the paucity of emotion many schizoids display, which would influence their thought patterns as well.[23]
Socialization groups may help people with SzPD. Educational strategies in which people who have SzPD identify their positive and negative emotions also may be effective. Such identification helps them to learn about their own emotions and the emotions they draw out from others and to feel the common emotions with other people with whom they relate. This can help people with SzPD create empathy with the outside world.
Shorter-term treatment
The concept of "closer compromise" means that the schizoid patient may be encouraged to experience intermediate positions between the extremes of emotional closeness and permanent exile.[19] A lack of injections of interpersonal reality causes an impoverishment in which the schizoid individual's self-image becomes increasingly empty and volatilized and leads the individual to feel unreal.[22] To create a more adaptive and self-enriching interaction with others in which one "feels real", the patient is encouraged to take risks through greater connection, communication and sharing of ideas, feelings and actions. Closer compromise means that while the patient's vulnerability to anxieties is not overcome, it is modified and managed more adaptively. Here, the therapist repeatedly conveys to the patient that anxiety is inevitable but manageable, without any illusion that the vulnerability to such anxiety can be permanently dispensed with. The limiting factor is the point at which the dangers of intimacy become overwhelming and the patient must again retreat.
Klein suggests that patients must take the responsibility to place themselves at risk and to take the initiative for following through with treatment suggestions in their personal lives. It is emphasized that these are the therapist's impressions and that he or she is not reading the patient's mind or imposing an agenda but is simply stating a position that is an extension of the patient's therapeutic wish. Finally, the therapist directs attention to the need to employ these actions outside of the therapeutic setting.[19]
Longer-term therapy
Klein suggests that "working through" is the second longer-term tier of psychotherapeutic work with schizoid patients. Its goals are to change fundamentally the old ways of feeling and thinking and to rid oneself of the vulnerability to those emotions associated with old feelings and thoughts. A new therapeutic operation of "remembering with feeling" that draws on D. W. Winnicott's concepts of false self and true self is called for.[19] The patient must remember with feeling the emergence of his or her false self through childhood and remember the conditions and proscriptions that were imposed on the individual's freedom to experience the self in company with others.[19]
Remembering with feeling ultimately leads the patient to understand that he or she had no opportunity to choose from a selection of possible ways of experiencing the self and of relating with others and had few, if any, options other than to develop a schizoid stance toward others. The false self was simply the best way in which the patient could experience the repetitive predictable acknowledgement, affirmation and approval necessary for emotional survival while warding off the effects associated with the abandonment depression.[19]
If the goal of shorter-term therapy is for patients to understand that they are not the way they appear to be and can act differently, then the longer-term goal of working through is for patients to understand who and what they are as human beings, what they truly are like and what they truly contain. The goal of working through is not achieved by the patient's sudden discovery of a hidden, fully formed talented and creative self living inside, but is a process of slowly freeing oneself from the confinement of abandonment depression in order to uncover a potential. It is a process of experimentation with the spontaneous, nonreactive elements that can be experienced in relationship with others.
Working through abandonment depression is a complicated, lengthy and conflicted process that can be an enormously painful experience in terms of what is remembered and what must be felt. It involves mourning and grieving for the loss of the illusion that the patient had adequate support for the emergence of the real self. There is also a mourning for the loss of an identity, the false self, which the person constructed and with which he or she has negotiated much of his or her life. The dismantling of the false self requires relinquishing the only way that the patient has ever known of how to interact with others. This interaction was better than not to have a stable, organized experience of the self, no matter how false, defensive or destructive that identity may be.
The dismantling of the false self "leaves the impaired real self with the opportunity to convert its potential and its possibilities into actualities."[19] Working through brings unique rewards, of which the most important element is the growing realization that the individual has a fundamental, internal need for relatedness that may be expressed in a variety of ways. "Only schizoid patients", suggests Klein, "who have worked through the abandonment depression ... ultimately will believe that the capacity for relatedness and the wish for relatedness are woven into the structure of their beings, that they are truly part of who the patients are and what they contain as human beings. It is this sense that finally allows the schizoid patient to feel the most intimate sense of being connected with humanity more generally, and with another person more personally. For the schizoid patient, this degree of certainty is the most gratifying revelation, and a profound new organizer of the self experience."[19]: 127
Development and course
SzPD can be first apparent in childhood and adolescence with solitariness, poor peer relationships and underachievement in school. This may mark these children as different and make them subject to teasing.[18][44]
Being a personality disorder, which is usually chronic and long-lasting mental conditions, SzPD is not expected to improve with time without treatment; however, much remains unknown because it is rarely encountered in clinical settings.[6]
There has been an especially large contribution of people with schizoid symptoms to science and theoretical areas of knowledge, including maths, physics, economics, etc. At the same time, people with SzPD are helpless at many practical activities because of their symptoms.[72]
Epidemiology
SzPD is uncommon in clinical settings (about 2.2%) and occurs more commonly in males. It is rare compared with other personality disorders, with a prevalence estimated at less than 1% of the general population.[4][8][11]
Philip Manfield suggests that the "schizoid condition", which roughly includes the DSM schizoid, avoidant and schizotypal personality disorders, is represented by "as many as forty percent of all personality disorders." Manfield adds "This huge discrepancy [from the ten percent reported by therapists for the condition] is probably largely because someone with a schizoid disorder is less likely to seek treatment than someone with other axis II disorders."[26][73]
A 2008 study assessing personality and mood disorder prevalence among homeless people at New York City drop-in centres reported an SzPD rate of 65% among this sample. The study did not assess homeless people who did not show up at drop-in centres, and the rates of most other personality and mood disorders within the drop-in centres was lower than that of SzPD. The authors noted the limitations of the study, including the higher male-to-female ratio in the sample and the absence of subjects outside the support system or receiving other support (e.g., shelters) as well as the absence of subjects in geographical settings outside New York City, a large city often considered a magnet for disenfranchised people.[74]
A University of Colorado Colorado Springs study comparing personality disorders and Myers–Briggs Type Indicator types found that the disorder had a significant correlation with the Introverted (I) and Thinking (T) preferences.[75]
Criticism
Nancy McWilliams of Rutgers University and Parpottas Panagiotis of European University Cyprus have argued that the definition of SzPD is flawed due to cultural bias and that it does not constitute a mental disorder but simply an avoidant attachment style requiring more emotional distance.[76][77] If that is true, then many of the more problematic reactions these individuals show in social situations may be partly accounted for by the judgements commonly imposed on people with this style. However, impairment is mandatory for classification as a personality disorder. SzPD seems to satisfy this criterion because it is linked to negative outcomes, including reduced overall functioning even after 15 years and among the lowest levels of quality of life and "life success" for all personality disorders (measured as "status, wealth and successful relationships").[8][9][10] However, determination of what qualify as "impairments" or as "negative outcomes" is itself potentially subject to cultural bias. People with SzPD may not regard a lack of social-status or successful relationships, for example, as a harm. Furthermore, correlation with negative outcomes does not necessarily demonstrate that these outcomes were directly caused by the schizoid traits. Rather, it may be that these outcomes are the result of discrimination against people with SzPD, who may be viewed as abnormal.
Due to the poor consistency and efficiency of diagnosis due to overlapping traits, it has been argued that SzPD should be removed altogether from the DSM.[64] In 2012, an article called for the replacement of the SzPD category with a dimensional model which would allow for the description of schizoid traits on an individual basis,[10] suggesting that two different disorders may better represent SzPD: one affect-constricted disorder (belonging to schizotypal PD, see also "emotional detachment" in 6D11.1 of ICD-11 § Personality disorder) and a seclusive disorder (belonging to avoidant PD, see also "social detachment" in 6D11.1 of ICD-11 § Personality disorder).
Origin and historical definition
The term "schizoid" was coined in 1908 by Eugen Bleuler to designate a human tendency to direct attention toward one's inner life and away from the external world as a concept akin to introversion, not viewed in terms of psychopathology. Bleuler labeled the exaggeration of this tendency the "schizoid personality".[13] He described these personalities as "comfortably dull and at the same time sensitive, people who in a narrow manner pursue vague purposes".[78]
In 1910, August Hoch introduced a very similar concept called the "shut-in" personality, characterised by reticence, seclusiveness, shyness and a preference for living in fantasy worlds, among others.[78] In 1925, Russian psychiatrist Grunya Sukhareva described a "schizoid psychopathy" in a group of children, resembling today's SzPD and ASD. About a decade later Pyotr Gannushkin also included Schizoids and Dreamers in his detailed typology of personality types.[79]
Clinical studies
Studies on the schizoid personality have developed along two distinct paths.
Descriptive psychiatry tradition
The descriptive psychiatry tradition focuses on overtly observable, behavioral and describable symptoms and finds its clearest exposition in the DSM-5.
The descriptive psychiatry tradition began in 1925 with the description of observable schizoid behaviors by Ernst Kretschmer. He organized those into three groups of characteristics:[80]
- Unsociability, quietness, reservedness, seriousness and eccentricity.
- Timidity, shyness with feelings, sensitivity, nervousness, excitability, fondness of nature and books.
- Pliability, kindliness, honesty, indifference, silence and cold emotional attitudes.
These characteristics were the precursors of the DSM-III division of the schizoid character into three distinct personality disorders: schizotypal, avoidant and schizoid. Kretschmer himself, however, did not conceive of separating these behaviors to the point of radical isolation but considered them to be simultaneously present as varying potentials in schizoid individuals. For Kretschmer, the majority of schizoids are not either oversensitive or cold, but they are oversensitive and cold "at the same time" in quite different relative proportions, with a tendency to move along these dimensions from one behavior to the other.[80]
Dynamic psychiatry tradition
The dynamic psychiatry tradition includes the exploration of covert or unconscious motivations and character structure as elaborated by classic psychoanalysis and object-relations theory.
The dynamic psychiatry tradition began in 1924 with observations by Eugen Bleuler,[81] who observed that the schizoid person and schizoid pathology were not things to be set apart.[19]: p. 5 Ronald Fairbairn's seminal work on the schizoid personality, from which most of what is known today about schizoid phenomena is derived, was presented in 1940. Here, Fairbairn delineated four central schizoid themes:
- The need to regulate interpersonal distance as a central focus of concern.
- The ability to mobilize self-preservative defenses and self-reliance.
- A pervasive tension between the anxiety-laden need for attachment and the defensive need for distance that manifests in observable behavior as indifference.
- An overvaluation of the inner world at the expense of the outer world.[19]: p. 9
Following Fairbairn, the dynamic psychiatry tradition has continued to produce rich explorations on the schizoid character, most notably from writers Nannarello (1953),[39] Laing (1965),[22] Winnicott (1965),[82] Guntrip (1969),[83] Khan (1974),[33] Akhtar (1987),[13] Seinfeld (1991),[34] Manfield (1992)[26] and Klein (1995).[19]
Controversy
The original concept of the schizoid character developed by Kretschmer in the 1920s comprised an amalgamation of avoidant, schizotypal and schizoid traits. The work of Millon in the 1980s led to this concept being split into three distinct disorders. This caused debate about whether this was accurate or if these traits were different expressions of a single personality disorder.[78]
See also
- Asociality
- Counterphobic attitude
- Dissociation (psychology)
- Hermit
- Recluse
- Schizothymia
- Schizotypy
- Sluggish cognitive tempo
- Social alienation
- Social isolation
References
- "F60 Specific personality disorders" (PDF). The ICD-10 Classification of Mental and Behavioural Disorders – Diagnostic criteria for research. Geneva: World Health Organization. p. 149.
- American Psychiatric Association (1968). Diagnostic and Statistical Manual of Mental Disorders, 2nd Edition. Washington, D. C. p. 42. doi:10.1176/appi.books.9780890420355.dsm-ii (inactive 31 July 2022). ISBN 978-0-89042-035-5.
{{cite book}}
: CS1 maint: DOI inactive as of July 2022 (link) - Millon, Theodore; Millon, Carrie M.; Meagher, Sarah E. (2012). "The Schizoid Personality (Chapter 11)". Personality Disorders in Modern Life. Seth D. Grossman, Rowena Ramnath (2nd ed.). John Wiley & Sons. pp. 371–374. ISBN 978-0-471-23734-1.
- Michelle L. Esterberg (2010). "Cluster A Personality Disorders: Schizotypal, Schizoid and Paranoid Personality Disorders in Childhood and Adolescence". Journal of Psychopathology and Behavioral Assessment. 32 (4): 515–528. doi:10.1007/s10862-010-9183-8. PMC 2992453. PMID 21116455.
- "Schizoid Personality Disorder (pp. 652–655)". Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (2013). 2013. ISBN 978-0-89042-555-8.
- MedlinePlus (2014). "Schizoid Personality Disorder". National Library of Medicine.
- Sonny Joseph (1997). "Chapter 3, Schizoid Personality Disorder". Personality Disorders: New Symptom-Focused Drug Therapy. Psychology Press. pp. 45–56. ISBN 9780789001344.
- Paul Emmelkamp (2013): Personality Disorders. p.54. See Cramer (2006) and Hong (2005) for details.
- Skodol, Andrew E. (2011). "Personality Disorder Types Proposed for DSM-5". Journal of Personality Disorders. 25 (2): 136–69. doi:10.1521/pedi.2011.25.2.136. PMID 21466247.
It [SPD] was found by Ullrich, Farrington & Coid 2007 to have the lowest functioning among the PDs with respect to achievement and interpersonal relations...
- Ullrich, Simone; Farrington, David P.; Coid, Jeremy W. (December 2007). "Dimensions of DSM-IV Personality Disorders and Life-Success". Journal of Personality Disorders. 21 (6): 657–663. doi:10.1521/pedi.2007.21.6.657. PMID 18072866. S2CID 30040457.
- Joseph Triebwasser; et al. (2012). "Schizoid Personality Disorder". Journal of Personality Disorders. 26 (6): 919–926. doi:10.1521/pedi.2012.26.6.919. PMID 23281676. S2CID 19412458.
... it seems reasonable for DSM-5 to move away from ScPD as a categorical diagnosis and instead to include Detachment traits as a codable dimension that can have a substantial impact on an individual's functioning and quality of life, and that can moreover be a focus of treatment.
- Coid, Jeremy; Yang, Min; Tyrer, Peter; Roberts, Amanda; Ullrich, Simone (May 2006). "Prevalence and correlates of personality disorder in Great Britain". The British Journal of Psychiatry: The Journal of Mental Science. 188 (5): 423–31. doi:10.1192/bjp.188.5.423. ISSN 0007-1250. PMID 16648528.
- Arthur S. Reber (2009) [1985]. The Penguin Dictionary of Psychology (4th ed.). London; New York: Penguin Books. p. 706. ISBN 9780141030241. OCLC 288985213.
- Salman Akhtar (1987). Schizoid Personality Disorder: A Synthesis of Developmental, Dynamic, and Descriptive Features. American Journal of Psychotherapy. Vol. 41. pp. 499–518. doi:10.1176/appi.psychotherapy.1987.41.4.499. ISBN 9781461627685. PMID 3324773. Archived from the original on 2017-07-31. Retrieved 2017-02-10.
- Dennis S. Charney, Eric J. Nestler (2005): Neurobiology of Mental Illness. Oxford Press. ISBN 978-0-19-518980-3. Schizophrenia-like Personality Disorders. p. 240.
- Lugnegård, Tove; Hallerbäck, Maria Unenge; Gillberg, Christopher (May 2012). "Personality disorders and autism spectrum disorders: what are the connections?". Comprehensive Psychiatry. 53 (4): 333–340. doi:10.1016/j.comppsych.2011.05.014. PMID 21821235.
- Cook, Michal L. (2019). "On the Continuity Between Autistic and Schizoid Personality Disorder Trait Burden: A Prospective Study in Adolescence". The Journal of Nervous and Mental Disease. 208 (2): 94–100. doi:10.1097/NMD.0000000000001105. PMC 6982569. PMID 31856140.
- "Schizoid personality disorder". Mayo Foundation for Medical Education and Research (2016).
- Descriptions from DSM-III (1980) and DSM-5 (2013):"Schizoid PD, Associated features (p. 310)" and "Schizoid PD (p. 652–655)".
- James F. Masterson; Ralph Klein (1995). Disorders of the Self – The Masterson Approach. New York: Brunner / Mazel. pp. 25–27, pp. 54–55, pp. 95–143 (therapy). ISBN 9780876307861.
- Levi-Belz, Y.; Gvion, Y.; Levi, U.; Apter, A. (2019). "Beyond the mental pain: A case-control study on the contribution of schizoid personality disorder symptoms to medically serious suicide attempts". Comprehensive Psychiatry. 90: 102–109. doi:10.1016/j.comppsych.2019.02.005. PMID 30852349.
- Attademo, Luigi; Bernardini, Francesco; Spatuzzi, Roberta (2021). "Suicidality in individuals with schizoid personality disorder or traits: a clinical mini-review of a probably underestimated issue" (PDF). Psychiatria Danubina. 33 (3): 261–265. doi:10.24869/psyd.2021.261. PMID 34795159. S2CID 244385145.
- Ronald D. Laing (1965). "The Inner Self in the Schizoid Condition". The Divided Self: an Existential Study in Sanity and Madness. Harmondsworth, Middlesex; Baltimore: Penguin Books. pp. 82–100. ISBN 9780140207347. OCLC 5212085.
- Aaron T. Beck; Arthur Freeman (1990). "Chapter 7 Schizoid and Schizotypal PD (p.120-146)". Cognitive Therapy of Personality Disorders (1st ed.). The Guilford Press. pp. 125 (Millon), 127–129 (cognitive therapy conceptualization). ISBN 9780898624342. OCLC 906420553.
- Sharon C. Ekleberry (2008). "Cluster A - Schizoid Personality Disorder and Substance Use Disorders". Integrated Treatment for Co-Occurring Disorders: Personality Disorders and Addiction. Routledge. pp. 31–32. ISBN 978-0789036933.
- Jeffrey J. Magnavita (1997). Restructuring Personality Disorders: A Short-Term Dynamic Approach. New York: The Guilford Press. p. 237. ISBN 978-1-57230-185-6.
- Philip Manfield (1992). Split self/split object: understanding and treating borderline, narcissistic, and schizoid disorders. Jason Aronson. pp. 204–207. ISBN 978-0-87668-460-3.
- Donald Winnicott (2006). The Family and Individual Development. Routledge. p. 73. ISBN 978-0415402774.
- Ernst Kretschmer (March 2013). "Chapter 10. Schizoid temperaments". Body structure and character. Studies on the constitution and theory of temperaments (in Russian). Ripol Classic. ISBN 9785458358392.
- "Treatment of schizoid personality: An analytic psychotherapy handbook - ProQuest". search.proquest.com. Retrieved 2019-08-22.
- Avner Falk (2008). Islamic Terror: Conscious and Unconscious Motives. ABC-CLIO. p. 98. ISBN 978-0-313-35764-0.
- Rosen, L. D.; Whaling, K.; Rab, S.; Carrier, L. M.; Cheever, N. A. (2013). "Is Facebook creating "iDisorders"? The link between clinical symptoms of psychiatric disorders and technology use, attitudes and anxiety". Computers in Human Behavior. 29 (3): 1243–1254. doi:10.1016/j.chb.2012.11.012. ISSN 0747-5632.
- W. R. D. Fairbairn (2013). Psychoanalytic Studies of the Personality. Routledge. pp. 3–17. ISBN 978-1-134-84213-1.
- Masud Khan (1974). "The Role of phobic and counter-phobic mechanisms and separation anxiety in schizoid character formation". The Privacy of the Self – Papers on Psychoanalytic Theory and Technique. New York: International Universities Press. p. 70. ISBN 978-0823643103.
- Jeffrey Seinfeld (1991). The Empty Core: An Object Relations Approach to Psychotherapy of the Schizoid Personality. J. Aronson. ISBN 978-0-87668-611-9.
Seinfeld writes: "The schizoid may also seem to be sociable and involved in relationships. However, he is frequently playing a role and not 'fully' involved, unconsciously disowning this role..."
- David Schuldberg (2001). "Six subclinical spectrum traits in normal creativity". Creativity Research Journal. 13 (1): 5–16. doi:10.1207/s15326934crj1301_2. S2CID 143791841.
- George Domino (2002). "Creativity and Ego Defense Mechanisms: Some Exploratory Empirical Evidence". Creativity Research Journal. 14 (1): 17–25. doi:10.1207/S15326934CRJ1401_2. S2CID 152269910.
- Kinney, Dennis K.; Richards, Ruth (2001). "Creativity in Offspring of Schizophrenic and Control Parents: An Adoption Study". Creativity Research Journal. 13 (1): 17–25. doi:10.1207/S15326934CRJ1301_3. S2CID 145560246.
- Donald Woods Winnicott (1991). Playing and Reality. Psychology Press. pp. 26–38. ISBN 978-0-415-03689-4.
- Nannarello, Joseph J. (1953). "Schizoid". The Journal of Nervous and Mental Disease. 118 (3): 237–249. doi:10.1097/00005053-195309000-00004. PMID 13118367.
- DiGiuseppe, Raymond; Tafrate, Raymond Chip (2007). Understanding Anger Disorders. Oxford University Press, USA. p. 207. ISBN 9780195170795.
- "Theodore Millon – The Retiring or Schizoid Personality". millonpersonality.com.
- Kenneth S. Kendler (2006). "Dimensional representations of DSM-IV Cluster A personality disorders in a population-based sample of Norwegian twins: a multivariate study". Psychological Medicine. 36 (11): 1583–1591. doi:10.1017/S0033291706008609. PMID 16893481. S2CID 21613637.
- Paul H. Blaney (2014). Oxford Textbook of Psychopathology. Oxford University Press. p. 649. ISBN 978-0-19-981184-7.
- Sula Wolff (1995). Loners – The Life Path of Unusual Children. Routledge. p. 35. ISBN 978-0-415-06665-5.
- Amber A. Mather (2008). "Associations Between Body Weight and Personality Disorders in a Nationally Representative Sample". Psychosomatic Medicine. 70 (9): 1012–1019. doi:10.1097/psy.0b013e318189a930. PMID 18842749. S2CID 26386820.
- Kathryn M. Abel (2010). "Birth weight, schizophrenia, and adult mental disorder: is risk confined to the smallest babies?". Archives of General Psychiatry. 67 (9): 923–930. doi:10.1001/archgenpsychiatry.2010.100. PMID 20819986.
- Willem H.J. Martens (2010). "Schizoid personality disorder linked to unbearable and inescapable loneliness". The European Journal of Psychiatry. 24 (1). doi:10.4321/S0213-61632010000100005.
- Brigham Young University (2014): Head injuries can make children loners. For original study, see Levan, Ashley; Baxter, Leslie; Kirwan, C. Brock; Black, Garrett; Gale, Shawn D (2015). "Right Frontal Pole Cortical Thickness and Social Competence in Children With Chronic Traumatic Brain Injury". Journal of Head Trauma Rehabilitation. 30 (2): E24–E31. doi:10.1097/HTR.0000000000000040. PMID 24714213. S2CID 20443326.
- R.L. Jenkins; S. Glickman (April 1946). "The Schizoid Child". American Journal of Orthopsychiatry. 16 (2): 255–61. doi:10.1111/j.1939-0025.1946.tb05379.x.
- James Overholser (1989) (November 1989). "Differentiation between schizoid and avoidant personalities: an empirical test". Canadian Journal of Psychiatry. 34 (8): 785–90. doi:10.1177/070674378903400808. PMID 2819642. S2CID 6222302.
- Malcolm L. West and A. E. Sheldon-Keller (1994). Patterns of Relating An Adult Attachment Perspective. New York: Guilford Press. pp. 111–113. ISBN 978-0-89862-671-1.
- Lenzenweger, Mark; Wastler, Heather (2019). "Self-referential hypermentalization in schizotypy". Personality Disorders: Theory, Research, and Treatment. 10 (6): 536–544. doi:10.1037/per0000344. PMID 31144838. S2CID 169040276.
- Somma, Antonella; Ferrara, Mauro; Terrinoni, Arianna; Frau, Claudia; Ardizzone, Ignazio; Sharp, Carla; Fossati, Andrea (April 2019). "Hypermentalizing as a marker of borderline personality disorder in Italian adolescents: a cross-cultural replication of Sharp and colleagues' (2011) findings". Borderline Personality Disorder and Emotion Dysregulation. 6: 5. doi:10.1186/s40479-019-0104-5. PMC 6457008. PMID 31007932.
- Ciaramidaro, Angela; Bolte, Sven; Schlitt, Sabine; Hainz, Daniela; Poustka, Fritz; Weber, Berndard; Bara, Bruno; Freitag, Christine; Walter, Henrik (January 2015). "Schizophrenia and autism as contrasting minds: neural evidence for the hypo-hyper-intentionality hypothesis". Schizophrenia Bulletin. 41 (1): 171–9. doi:10.1093/schbul/sbu124. PMC 4266299. PMID 25210055.
- Fritz-Georg Lehnhardt; Astrid Gawronski; Kathleen Pfeiffer; Hanna Kockler; Leonhard Schilbach; Kai Vogeley (2013). "The investigation and differential diagnosis of Asperger syndrome in adults". Deutsches Ärzteblatt International. 110 (45): 755–63. doi:10.3238/arztebl.2013.0755. PMC 3849991. PMID 24290364.
- World Health Organization (1993) – The ICD-10 Classification of Mental and Behavioural Disorders. "Simple schizophrenia" is classified F20.6.
- "ICD-11 - Mortality and Morbidity Statistics". World Health Organization. Retrieved 2019-08-22.
- "Appendix B: Criteria Sets and Axes Provided for Further Study". Diagnostic and Statistical Manual of Mental Disorders (4th ed.). American Psychiatric Association. 1994. p. 713. ISBN 9780890420621.
- Coolidge, Frederick L. (2012). "Are alexithymia and schizoid personality disorder synonymous diagnoses?". Comprehensive Psychiatry. 54 (2): 141–148. doi:10.1016/j.comppsych.2012.07.005. PMID 23021894. S2CID 15019411.
- Wolff, S.; Cull, A. (August 1986). "'Schizoid' personality and antisocial conduct: a retrospective case not study". Psychological Medicine. 16 (3): 677–687. doi:10.1017/S0033291700010424. ISSN 0033-2917. PMID 3763781. S2CID 35166577.
- Skinstad, Anne Helene; Swain, Annette (2001-01-01). "Comorbidity in a Clinical Sample of Substance Abusers". The American Journal of Drug and Alcohol Abuse. 27 (1): 45–64. doi:10.1081/ADA-100103118. ISSN 0095-2990. PMID 11373036. S2CID 2619787.
- Анатольевна, Панченко Евгения; Сергеевич, Положий Борис (2011). "Расстройства Личности у Пациентов, Совершивших Суицидальные Попытки" [Personality Disorders in Patients Who Have Committed Suicide Attempts]. Российский психиатрический журнал (3): 48–51. ISSN 1560-957X.
- Tantam, D. (December 1988). "Lifelong eccentricity and social isolation. II: Asperger's syndrome or schizoid personality disorder?". The British Journal of Psychiatry: The Journal of Mental Science. 153: 783–791. doi:10.1192/bjp.153.6.783. ISSN 0007-1250. PMID 3256377. S2CID 39433805.
- Hummelen, Benjamin; Pedersen, Geir; Wilberg, Theresa; Karterud, Sigmund (June 2015). "Poor Validity of theDSM-IVSchizoid Personality Disorder Construct as a Diagnostic Category". Journal of Personality Disorders. 29 (3): 334–346. doi:10.1521/pedi_2014_28_159. ISSN 0885-579X. PMID 25248009.
- Kuhn R (2004). "Eugen Bleuler's concepts of psychopathology". Hist Psychiatry. 15 (3): 361–366. doi:10.1177/0957154X04044603. PMID 15386868. S2CID 5317716. The quote is a translation of Bleuler's 1910 original.
- Cook, Michal (2019-05-03). "Pronounced Overlap of Autistic and Schizoid Personality Trait Burden in Adolescence". IMFAR.
- McVey, D. & Murphy, N. (eds.) (2010) Treating Personality Disorder: Creating Robust Services for People with Complex Mental Health Needs, ISBN 0-203-84115-8.
- Scoriels, Linda (2013). "Modafinil effects on cognition and emotion in schizophrenia and its neurochemical modulation in the brain". Neuropharmacology. 64: 168–184. doi:10.1016/j.neuropharm.2012.07.011. PMID 22820555. S2CID 17975469.
- Maher, Alicia R.; Theodore, George (2012). "Summary of the Comparative Effectiveness Review on Off-Label Use of Atypical Antipsychotics". Journal of Managed Care Pharmacy. 18 (5 Supp B): S1-20. doi:10.18553/jmcp.2012.18.s5-b.1. ISSN 1083-4087. PMID 22784311.
- McWilliams, Nancy (1994). Psychoanalytic diagnosis: understanding personality structure in the clinical process. New York: Guilford Press. pp. 480. ISBN 0898621992. OCLC 30035262.
- Ed. N. G. Neznanova; Yu. A. Alexandrovsky; L. M. Bardenshtein; V. D. Vida; V. N. Krasnov; Yu. V. Popov (2009). "Chapter 7. F6. Personality Disorders and Behavior in Adults". Psychiatry .-- S. . - 512 s. Clinical Recommendations Series. Moscow: GEOTAR-Media. pp. 304–307. ISBN 978-5-9704-1297-8.
- Белорусов, Сергей (2017-09-05). Очерки душевной патологии. И возможности ее коррекции соотносительно с духовным измерением бытия (in Russian). Litres. ISBN 9785040548330.
Especially important is the contribution of schizoid scientists in the theoretical fields of knowledge: mathematics, physics, economics. At the same time, schizoids are absolutely helpless in practical activities.
- George Eman Vaillant (1985). "Maturity of Ego Defenses in Relation to DSM-III Axis II Personality Disorder". Archives of General Psychiatry. 42 (6): 597–601. doi:10.1001/archpsyc.1985.01790290079009. PMID 4004502. Manfield backs his claim up with this study; it showed that of the seventy-four people inner city males found to have personality disorders, thirty were schizoid or avoidant.
- Connolly, Adrian J. (2008). "Personality disorders in homeless drop-in center clients" (PDF). Journal of Personality Disorders. 22 (6): 573–588. doi:10.1521/pedi.2008.22.6.573. PMID 19072678. Archived from the original (PDF) on 2009-06-17.
- "An Empirical Investigation of Jung's Personality Types and Psychological Disorder Features" (PDF). Journal of Psychological Type/University of Colorado Colorado Springs. 2001. Archived (PDF) from the original on 2014-01-25. Retrieved August 10, 2013.
- Nancy McWilliams (2011). Psychoanalytic Diagnosis: Understanding Personality Structure in the Clinical Process (2nd ed.). New York: Guilford Press. p. 196. ISBN 9781609184940.
- Parpottas Panagiotis (2012). "A critique on the use of standard psychopathological classifications in understanding human distress: The example of 'Schizoid Personality Disorder'". Counselling Psychology Review. 27 (1): 44–52.
- Livesley, W. J.; West, M. (February 1986). "The DSM-III Distinction between schizoid and avoidant personality disorders". Canadian Journal of Psychiatry. 31 (1): 59–62. doi:10.1177/070674378603100112. PMID 3948107. S2CID 46283956.
- Both types shared a detachment from the world but Schizoids also showed eccentricity and paradoxicality of emotional life and behavior, emotional coldness and dryness, unpredictability combined with lack of intuition and ambivalence (e.g., simultaneous presence of both stubbornness and submissiveness). Characteristic of Dreamers were tenderness and fragility, receptiveness to beauty, weak-willedness and listlessness, luxuriant imagination, dereism and usually an inflated self-concept. (From: Gannushkin, P.B (1933). Manifestations of psychopathies: statics, dynamics, systematic aspects.)
- Ernst Kretschmer (1931). Physique and Character. London: Routledge (International Library of Psychology,1999). ISBN 978-0-415-21060-7. OCLC 858861653.
- Eugen Bleuler – Textbook of Psychiatry, New York: Macmillan (1924)
- Donald Winnicott (1965): The Maturational Processes and the Facilitating Environment: Studies in the Theory of Emotional Development. Karnac Books. ISBN 9780946439843.
- Harry Guntrip (1969). Schizoid Phenomena, Object-Relations, and The Self. New York: International Universities Press. ISBN 978-1-85575-032-6.