Alcoholism

Some of the possible long-term effects of ethanol an individual may develop. Additionally, in pregnant women, alcohol can cause fetal alcohol syndrome.

Alcoholism is characterised by an increased tolerance to alcohol – which means that an individual can consume more alcohol – and physical dependence on alcohol, which makes it hard for an individual to control their consumption. The physical dependency caused by alcohol can lead to an affected individual having a very strong urge to drink alcohol. These characteristics play a role in decreasing the ability to stop drinking of an individual with an alcohol use disorder.[30] Alcoholism can have adverse effects on mental health, contributing to psychiatric disorders and increasing the risk of suicide. A depressed mood is a common symptom of heavy alcohol drinkers.[31][32]

Warning signs of alcoholism include the consumption of increasing amounts of alcohol and frequent intoxication, preoccupation with drinking to the exclusion of other activities, promises to quit drinking and failure to keep those promises, the inability to remember what was said or done while drinking (colloquially known as "blackouts"), personality changes associated with drinking, denial or the making of excuses for drinking, the refusal to admit excessive drinking, dysfunction or other problems at work or school, the loss of interest in personal appearance or hygiene, marital and economic problems, and the complaint of poor health, with loss of appetite, respiratory infections, or increased anxiety.[33]

Drinking enough to cause a blood alcohol concentration (BAC) of 0.03–0.12% typically causes an overall improvement in mood and possible euphoria (a "happy" feeling), increased self-confidence and sociability, decreased anxiety, a flushed, red appearance in the face and impaired judgment and fine muscle coordination. A BAC of 0.09% to 0.25% causes lethargy, sedation, balance problems and blurred vision. A BAC of 0.18% to 0.30% causes profound confusion, impaired speech (e.g. slurred speech), staggering, dizziness and vomiting. A BAC from 0.25% to 0.40% causes stupor, unconsciousness, anterograde amnesia, vomiting (death may occur due to inhalation of vomit while unconscious) and respiratory depression (potentially life-threatening). A BAC from 0.35% to 0.80% causes a coma (unconsciousness), life-threatening respiratory depression and possibly fatal alcohol poisoning. With all alcoholic beverages, drinking while driving, operating an aircraft or heavy machinery increases the risk of an accident; many countries have penalties for drunk driving.

Having more than one drink a day for women or two drinks for men increases the risk of heart disease, high blood pressure, atrial fibrillation, and stroke.[34] Risk is greater with binge drinking, which may also result in violence or accidents. About 3.3 million deaths (5.9% of all deaths) are believed to be due to alcohol each year.[13] Alcoholism reduces a person's life expectancy by around ten years[27] and alcohol use is the third leading cause of early death in the United States.[34] Long-term alcohol misuse can cause a number of physical symptoms, including cirrhosis of the liver, pancreatitis, epilepsy, polyneuropathy, alcoholic dementia, heart disease, nutritional deficiencies, peptic ulcers[35] and sexual dysfunction, and can eventually be fatal. Other physical effects include an increased risk of developing cardiovascular disease, malabsorption, alcoholic liver disease, and several cancers. Damage to the central nervous system and peripheral nervous system can occur from sustained alcohol consumption.[36][37] A wide range of immunologic defects can result and there may be a generalized skeletal fragility, in addition to a recognized tendency to accidental injury, resulting in a propensity for bone fractures.[38]

Women develop long-term complications of alcohol dependence more rapidly than do men, women also have a higher mortality rate from alcoholism than men.[39] Examples of long-term complications include brain, heart, and liver damage[40] and an increased risk of breast cancer. Additionally, heavy drinking over time has been found to have a negative effect on reproductive functioning in women. This results in reproductive dysfunction such as anovulation, decreased ovarian mass, problems or irregularity of the menstrual cycle, and early menopause.[39] Alcoholic ketoacidosis can occur in individuals who chronically misuse alcohol and have a recent history of binge drinking.[41][42] The amount of alcohol that can be biologically processed and its effects differ between sexes. Equal dosages of alcohol consumed by men and women generally result in women having higher blood alcohol concentrations (BACs), since women generally have a lower weight and higher percentage of body fat and therefore a lower volume of distribution for alcohol than men.[43]

Long-term misuse of alcohol can cause a wide range of mental health problems. Severe cognitive problems are common; approximately 10% of all dementia cases are related to alcohol consumption, making it the second leading cause of dementia.[44] Excessive alcohol use causes damage to brain function, and psychological health can be increasingly affected over time.[45] Social skills are significantly impaired in people with alcoholism due to the neurotoxic effects of alcohol on the brain, especially the prefrontal cortex area of the brain. The social skills that are impaired by alcohol use disorder include impairments in perceiving facial emotions, prosody, perception problems, and theory of mind deficits; the ability to understand humor is also impaired in people who misuse alcohol.[46] Psychiatric disorders are common in people with alcohol use disorders, with as many as 25% also having severe psychiatric disturbances. The most prevalent psychiatric symptoms are anxiety and depression disorders. Psychiatric symptoms usually initially worsen during alcohol withdrawal, but typically improve or disappear with continued abstinence.[47] Psychosis, confusion, and organic brain syndrome may be caused by alcohol misuse, which can lead to a misdiagnosis such as schizophrenia.[48] Panic disorder can develop or worsen as a direct result of long-term alcohol misuse.[49][50]

The co-occurrence of major depressive disorder and alcoholism is well documented.[51][52][53] Among those with comorbid occurrences, a distinction is commonly made between depressive episodes that remit with alcohol abstinence ("substance-induced"), and depressive episodes that are primary and do not remit with abstinence ("independent" episodes).[54][55][56] Additional use of other drugs may increase the risk of depression.[57] Psychiatric disorders differ depending on gender. Women who have alcohol-use disorders often have a co-occurring psychiatric diagnosis such as major depression, anxiety, panic disorder, bulimia, post-traumatic stress disorder (PTSD), or borderline personality disorder. Men with alcohol-use disorders more often have a co-occurring diagnosis of narcissistic or antisocial personality disorder, bipolar disorder, schizophrenia, impulse disorders or attention deficit/hyperactivity disorder (ADHD).[58] Women with alcohol use disorder are more likely to experience physical or sexual assault, abuse, and domestic violence than women in the general population,[58] which can lead to higher instances of psychiatric disorders and greater dependence on alcohol.

Serious social problems arise from alcohol use disorder; these dilemmas are caused by the pathological changes in the brain and the intoxicating effects of alcohol.[44][59] Alcohol misuse is associated with an increased risk of committing criminal offences, including child abuse, domestic violence, rape, burglary and assault.[60] Alcoholism is associated with loss of employment,[61] which can lead to financial problems. Drinking at inappropriate times and behavior caused by reduced judgment can lead to legal consequences, such as criminal charges for drunk driving[62] or public disorder, or civil penalties for tortious behavior. An alcoholic's behavior and mental impairment while drunk can profoundly affect those surrounding him and lead to isolation from family and friends. This isolation can lead to marital conflict and divorce, or contribute to domestic violence. Alcoholism can also lead to child neglect, with subsequent lasting damage to the emotional development of children of people with alcohol use disorders.[63] For this reason, children of people with alcohol use disorders can develop a number of emotional problems. For example, they can become afraid of their parents, because of their unstable mood behaviors. They may develop shame over their inadequacy to liberate their parents from alcoholism and, as a result of this, may develop self-image problems, which can lead to depression.[64]

"The bottle has done its work". Reproduction of an etching by G. Cruikshank, 1847.

As with similar substances with a sedative-hypnotic mechanism, such as barbiturates and benzodiazepines, withdrawal from alcohol dependence can be fatal if it is not properly managed.[59][65] Alcohol's primary effect is the increase in stimulation of the GABA_A receptor, promoting central nervous system depression. With repeated heavy consumption of alcohol, these receptors are desensitized and reduced in number, resulting in tolerance and physical dependence. When alcohol consumption is stopped too abruptly, the person's nervous system experiences uncontrolled synapse firing. This can result in symptoms that include anxiety, life-threatening seizures, delirium tremens, hallucinations, shakes and possible heart failure.[66][67] Other neurotransmitter systems are also involved, especially dopamine, NMDA and glutamate.[30][68]

Severe acute withdrawal symptoms such as delirium tremens and seizures rarely occur after 1-week post cessation of alcohol. The acute withdrawal phase can be defined as lasting between one and three weeks. In the period of 3–6 weeks following cessation, anxiety, depression, fatigue, and sleep disturbance are common.[69] Similar post-acute withdrawal symptoms have also been observed in animal models of alcohol dependence and withdrawal.[70]

A kindling effect also occurs in people with alcohol use disorders whereby each subsequent withdrawal syndrome is more severe than the previous withdrawal episode; this is due to neuroadaptations which occur as a result of periods of abstinence followed by re-exposure to alcohol. Individuals who have had multiple withdrawal episodes are more likely to develop seizures and experience more severe anxiety during withdrawal from alcohol than alcohol-dependent individuals without a history of past alcohol withdrawal episodes. The kindling effect leads to persistent functional changes in brain neural circuits as well as to gene expression.[71] Kindling also results in the intensification of psychological symptoms of alcohol withdrawal.[69] There are decision tools and questionnaires that help guide physicians in evaluating alcohol withdrawal. For example, the CIWA-Ar objectifies alcohol withdrawal symptoms in order to guide therapy decisions which allows for an efficient interview while at the same time retaining clinical usefulness, validity, and reliability, ensuring proper care for withdrawal patients, who can be in danger of death.[72]

Alcohol is the most available, widely consumed, and widely misused recreational drug. Beer alone is the world's most widely consumed[80] alcoholic beverage; it is the third-most popular drink overall, after water and tea.[81] It is thought by some to be the oldest fermented beverage.[82][83][84][85]

Based on combined data in the US from SAMHSA's 2004–2005 National Surveys on Drug Use & Health, the rate of past-year alcohol dependence or misuse among persons aged 12 or older varied by level of alcohol use: 44.7% of past month heavy drinkers, 18.5% binge drinkers, 3.8% past month non-binge drinkers, and 1.3% of those who did not drink alcohol in the past month met the criteria for alcohol dependence or misuse in the past year. Males had higher rates than females for all measures of drinking in the past month: any alcohol use (57.5% vs. 45%), binge drinking (30.8% vs. 15.1%), and heavy alcohol use (10.5% vs. 3.3%), and males were twice as likely as females to have met the criteria for alcohol dependence or misuse in the past year (10.5% vs. 5.1%).[86]

There are genetic variations that affect the risk for alcoholism.[74][73][87][88] Some of these variations are more common in individuals with ancestry from certain areas, for example Africa, East Asia, the Middle East and Europe. The variants with strongest effect are in genes that encode the main enzymes of alcohol metabolism, ADH1B and ALDH2.[74][87][88] These genetic factors influence the rate at which alcohol and its initial metabolic product, acetaldehyde, are metabolized.[74] They are found at different frequencies in people from different parts of the world.[89][74][90] The alcohol dehydrogenase allele ADH1B*2 causes a more rapid metabolism of alcohol to acetaldehyde, and reduces risk for alcoholism;[74] it is most common in individuals from East Asia and the Middle East. The alcohol dehydrogenase allele ADH1B*3 also causes a more rapid metabolism of alcohol. The allele ADH1B*3 is only found in some individuals of African descent and certain Native American tribes. African Americans and Native Americans with this allele have a reduced risk of developing alcoholism.[74][90][91] Native Americans, however, have a significantly higher rate of alcoholism than average; risk factors such as cultural environmental effects (e.g. trauma) have been proposed to explain the higher rates.[92][93] The aldehyde dehydrogenase allele ALDH2*2 greatly reduces the rate at which acetaldehyde, the initial product of alcohol metabolism, is removed by conversion to acetate; it greatly reduces the risk for alcoholism.[74][89]

A genome-wide association study (GWAS) of more than 100,000 human individuals identified variants of the gene KLB, which encodes the transmembrane protein β-Klotho, as highly associated with alcohol consumption. The protein β-Klotho is an essential element in cell surface receptors for hormones involved in modulation of appetites for simple sugars and alcohol.[94] Several large GWAS have found differences in the genetics of alcohol consumption and alcohol dependence, although the two are to some degree related.[87][88][95]

Alcohol-induced DNA damage, when not properly repaired, may have a key role in the neurotoxicity induced by alcohol.[96] Metabolic conversion of ethanol to acetaldehyde can occur in the brain and the neurotoxic effects of ethanol appear to be associated with acetaldehyde induced DNA damages including DNA adducts and crosslinks.[96] In addition to acetaldehyde, alcohol metabolism produces potentially genotoxic reactive oxygen species, which have been demonstrated to cause oxidative DNA damage.[96]

A man drinking from a bottle of liquor while sitting on a boardwalk, ca. 1905–1914. Picture by Austrian photographer Emil Mayer.

Misuse, problem use, abuse, and heavy use of alcohol refer to improper use of alcohol, which may cause physical, social, or moral harm to the drinker.[97] The Dietary Guidelines for Americans defines "moderate use" as no more than two alcoholic beverages a day for men and no more than one alcoholic beverage a day for women.[98] The National Institute on Alcohol Abuse and Alcoholism (NIAAA) defines binge drinking as the amount of alcohol leading to a blood alcohol content (BAC) of 0.08, which, for most adults, would be reached by consuming five drinks for men or four for women over a two-hour period. According to the NIAAA, men may be at risk for alcohol-related problems if their alcohol consumption exceeds 14 standard drinks per week or 4 drinks per day, and women may be at risk if they have more than 7 standard drinks per week or 3 drinks per day. It defines a standard drink as one 12-ounce bottle of beer, one 5-ounce glass of wine, or 1.5 ounces of distilled spirits.[99] Despite this risk, a 2014 report in the National Survey on Drug Use and Health found that only 10% of either "heavy drinkers" or "binge drinkers" defined according to the above criteria also met the criteria for alcohol dependence, while only 1.3% of non-binge drinkers met the criteria. An inference drawn from this study is that evidence-based policy strategies and clinical preventive services may effectively reduce binge drinking without requiring addiction treatment in most cases.[100]

The term alcoholism is commonly used amongst laypeople, but the word is poorly defined. Despite the imprecision inherent in the term, there have been attempts to define how the word alcoholism should be interpreted when encountered. In 1992, it was defined by the National Council on Alcoholism and Drug Dependence (NCADD) and ASAM as "a primary, chronic disease characterized by impaired control over drinking, preoccupation with the drug alcohol, use of alcohol despite adverse consequences, and distortions in thinking."[101] MeSH has had an entry for alcoholism since 1999, and references the 1992 definition.[102]

The WHO calls alcoholism "a term of long-standing use and variable meaning", and use of the term was disfavored by a 1979 WHO expert committee.

In professional and research contexts, the term alcoholism is not currently favored, but rather alcohol abuse, alcohol dependence, or alcohol use disorder are used.[4][2] Talbot (1989) observes that alcoholism in the classical disease model follows a progressive course: if a person continues to drink, their condition will worsen. This will lead to harmful consequences in their life, physically, mentally, emotionally and socially.[103] Johnson (1980) explores the emotional progression of the addict's response to alcohol. He looks at this in four phases. The first two are considered "normal" drinking and the last two are viewed as "typical" alcoholic drinking.[103] Johnson's four phases consist of:

1. Learning the mood swing. A person is introduced to alcohol (in some cultures this can happen at a relatively young age), and the person enjoys the happy feeling it produces. At this stage, there is no emotional cost.
2. Seeking the mood swing. A person will drink to regain that feeling of euphoria experienced in phase 1; the drinking will increase as more intoxication is required to achieve the same effect. Again at this stage, there are no significant consequences.
3. At the third stage there are physical and social consequences, i.e., hangovers, family problems, work problems, etc. A person will continue to drink excessively, disregarding the problems.
4. The fourth stage can be detrimental, as Johnson cites it as a risk for premature death. As a person now drinks to feel normal, they block out the feelings of overwhelming guilt, remorse, anxiety, and shame they experience when sober.[103]

In the United States, the Diagnostic and Statistical Manual of Mental Disorders (DSM) is the most common diagnostic guide for substance use disorders, whereas most countries use the International Classification of Diseases (ICD) for diagnostic (and other) purposes. The two manuals use similar but not identical nomenclature to classify alcohol problems.

Attitudes and social stereotypes can create barriers to the detection and treatment of alcohol use disorder. This is more of a barrier for women than men. Fear of stigmatization may lead women to deny that they have a medical condition, to hide their drinking, and to drink alone. This pattern, in turn, leads family, physicians, and others to be less likely to suspect that a woman they know has alcohol use disorder.[39] In contrast, reduced fear of stigma may lead men to admit that they are having a medical condition, to display their drinking publicly, and to drink in groups. This pattern, in turn, leads family, physicians, and others to be more likely to suspect that a man they know is someone with an alcohol use disorder.[58]

Screening is recommended among those over the age of 18.[113] Several tools may be used to detect a loss of control of alcohol use. These tools are mostly self-reports in questionnaire form. Another common theme is a score or tally that sums up the general severity of alcohol use.[114]

The CAGE questionnaire, named for its four questions, is one such example that may be used to screen patients quickly in a doctor's office.

Two "yes" responses indicate that the respondent should be investigated further.

The questionnaire asks the following questions:

1. Have you ever felt you needed to Cut down on your drinking?
2. Have people Annoyed you by criticizing your drinking?
3. Have you ever felt Guilty about drinking?
4. Have you ever felt you needed a drink first thing in the morning (Eye-opener) to steady your nerves or to get rid of a hangover?[115][116]

The CAGE questionnaire has demonstrated a high effectiveness in detecting alcohol-related problems; however, it has limitations in people with less severe alcohol-related problems, white women and college students.[117]

Other tests are sometimes used for the detection of alcohol dependence, such as the Alcohol Dependence Data Questionnaire, which is a more sensitive diagnostic test than the CAGE questionnaire. It helps distinguish a diagnosis of alcohol dependence from one of heavy alcohol use.[118] The Michigan Alcohol Screening Test (MAST) is a screening tool for alcoholism widely used by courts to determine the appropriate sentencing for people convicted of alcohol-related offenses,[119] driving under the influence being the most common. The Alcohol Use Disorders Identification Test (AUDIT), a screening questionnaire developed by the World Health Organization, is unique in that it has been validated in six countries and is used internationally. Like the CAGE questionnaire, it uses a simple set of questions – a high score earning a deeper investigation.[120] The Paddington Alcohol Test (PAT) was designed to screen for alcohol-related problems amongst those attending Accident and Emergency departments. It concords well with the AUDIT questionnaire but is administered in a fifth of the time.[121]

There are reliable tests for the actual use of alcohol, one common test being that of blood alcohol content (BAC).[122] These tests do not differentiate people with alcohol use disorders from people without; however, long-term heavy drinking does have a few recognizable effects on the body, including:[123]

• Macrocytosis (enlarged MCV)
• Elevated GGT
• Moderate elevation of AST and ALT and an AST: ALT ratio of 2:1
• High carbohydrate deficient transferrin (CDT)

With regard to alcoholism, BAC is useful to judge alcohol tolerance, which in turn is a sign of alcoholism.[4] Electrolyte and acid-base abnormalities including hypokalemia, hypomagnesemia, hyponatremia, hyperuricemia, metabolic acidosis, and respiratory alkalosis are common in people with alcohol use disorders.[5]

However, none of these blood tests for biological markers is as sensitive as screening questionnaires.

Medical treatment for alcohol detoxification usually involves administration of a benzodiazepine, in order to ameliorate alcohol withdrawal syndrome's adverse impact.[128][129] The addition of phenobarbital improves outcomes if benzodiazepine administration lacks the usually efficacy, and phenobarbital alone might be an effective treatment.[130] Propofol also might enhance treatment for individuals showing limited therapeutic response to a benzodiazepine.[131][132] Individuals who are only at risk of mild to moderate withdrawal symptoms can be treated as outpatients. Individuals at risk of a severe withdrawal syndrome as well as those who have significant or acute comorbid conditions can be treated as inpatients. Direct treatment can be followed by a treatment program for alcohol dependence or alcohol use disorder to attempt to reduce the risk of relapse.[9] Experiences following alcohol withdrawal, such as depressed mood and anxiety, can take weeks or months to abate while other symptoms persist longer due to persisting neuroadaptations.[69]

A regional service center for Alcoholics Anonymous.

Various forms of group therapy or psychotherapy are often utilized to encourage and support abstinence from alcohol, or to reduce alcohol consumption to levels that are not associated with adverse outcomes. Mutual-aid group-counseling is an approach used to facilitate relapse prevention.[8] Alcoholics Anonymous was one of the earliest organizations formed to provide mutual peer support and it is still the largest. Others include LifeRing Secular Recovery, SMART Recovery, Women for Sobriety, and Secular Organizations for Sobriety.[133]

Manualized[134] Twelve Step Facilitation (TSF) interventions (i.e. therapy which encourages active, long-term Alcoholics Anonymous participation) for Alcohol Use Disorder lead to higher abstinence rates, compared to other clinical interventions and to wait-list control groups.[135]

Rationing and moderation programs such as Moderation Management and DrinkWise do not mandate complete abstinence. While most people with alcohol use disorders are unable to limit their drinking in this way, some return to moderate drinking. A 2002 US study by the National Institute on Alcohol Abuse and Alcoholism (NIAAA) showed that 17.7% of individuals diagnosed as alcohol dependent more than one year prior returned to low-risk drinking. This group, however, showed fewer initial symptoms of dependency.[136]

A follow-up study, using the same subjects that were judged to be in remission in 2001–2002, examined the rates of return to problem drinking in 2004–2005. The study found abstinence from alcohol was the most stable form of remission for recovering alcoholics.[137] There was also a 1973 study showing chronic alcoholics drinking moderately again,[138] but a 1982 follow-up showed that 95% of subjects were not able to maintain drinking in moderation over the long term.[139][140] Another study was a long-term (60 year) follow-up of two groups of alcoholic men which concluded that "return to controlled drinking rarely persisted for much more than a decade without relapse or evolution into abstinence."[141] Internet based measures appear to be useful at least in the short term.[142]

In the United States there are four approved medications for alcoholism: acamprosate, two methods of using naltrexone and disulfiram.[143]

• Acamprosate may stabilise the brain chemistry that is altered due to alcohol dependence via antagonising the actions of glutamate, a neurotransmitter which is hyperactive in the post-withdrawal phase.[144] By reducing excessive NMDA activity which occurs at the onset of alcohol withdrawal, acamprosate can reduce or prevent alcohol withdrawal related neurotoxicity.[145] Acamprosate reduces the risk of relapse amongst alcohol-dependent persons.[146][147]
• Naltrexone is a competitive antagonist for opioid receptors, effectively blocking the effects of endorphins and opioids. Naltrexone is used to decrease cravings for alcohol and encourage abstinence. Alcohol causes the body to release endorphins, which in turn release dopamine and activate the reward pathways; hence in the body Naltrexone reduces the pleasurable effects from consuming alcohol.[148] Evidence supports a reduced risk of relapse among alcohol-dependent persons and a decrease in excessive drinking.[147] Nalmefene also appears effective and works in a similar manner.[147]
• Disulfiram prevents the elimination of acetaldehyde, a chemical the body produces when breaking down ethanol. Acetaldehyde itself is the cause of many hangover symptoms from alcohol use. The overall effect is discomfort when alcohol is ingested: an extremely fast-acting and long-lasting, uncomfortable hangover.

Several other drugs are also used and many are under investigation.

• Benzodiazepines, while useful in the management of acute alcohol withdrawal, if used long-term can cause a worse outcome in alcoholism. Alcoholics on chronic benzodiazepines have a lower rate of achieving abstinence from alcohol than those not taking benzodiazepines. This class of drugs is commonly prescribed to alcoholics for insomnia or anxiety management.[149] Initiating prescriptions of benzodiazepines or sedative-hypnotics in individuals in recovery has a high rate of relapse with one author reporting more than a quarter of people relapsed after being prescribed sedative-hypnotics. Those who are long-term users of benzodiazepines should not be withdrawn rapidly, as severe anxiety and panic may develop, which are known risk factors for alcohol use disorder relapse. Taper regimes of 6–12 months have been found to be the most successful, with reduced intensity of withdrawal.[150][151]
• Calcium carbimide works in the same way as disulfiram; it has an advantage in that the occasional adverse effects of disulfiram, hepatotoxicity and drowsiness, do not occur with calcium carbimide.[152]
• Ondansetron and topiramate are supported by tentative evidence in people with certain genetic patterns.[153][154] Evidence for ondansetron is stronger in people who have recently started to abuse alcohol.[153] Topiramate is a derivative of the naturally occurring sugar monosaccharide D-fructose. Review articles characterize topiramate as showing "encouraging",[153] "promising",[153] "efficacious",[155] and "insufficient"[156] results in the treatment of alcohol use disorders.

Evidence does not support the use of selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs), antipsychotics, or gabapentin.[147]

Alcoholics may also require treatment for other psychotropic drug addictions and drug dependencies. The most common dual dependence syndrome with alcohol dependence is benzodiazepine dependence, with studies showing 10–20% of alcohol-dependent individuals had problems of dependence and/or misuse problems of benzodiazepine drugs such as diazepam or clonazepam. These drugs are, like alcohol, depressants. Benzodiazepines may be used legally, if they are prescribed by doctors for anxiety problems or other mood disorders, or they may be purchased as illegal drugs. Benzodiazepine use increases cravings for alcohol and the volume of alcohol consumed by problem drinkers.[163] Benzodiazepine dependency requires careful reduction in dosage to avoid benzodiazepine withdrawal syndrome and other health consequences. Dependence on other sedative-hypnotics such as zolpidem and zopiclone as well as opiates and illegal drugs is common in alcoholics. Alcohol itself is a sedative-hypnotic and is cross-tolerant with other sedative-hypnotics such as barbiturates, benzodiazepines and nonbenzodiazepines. Dependence upon and withdrawal from sedative-hypnotics can be medically severe and, as with alcohol withdrawal, there is a risk of psychosis or seizures if not properly managed.[164]