Alcohol and drug dependence

Alcohol and drug dependence are diagnosed based on the clustering of characteristic physiological and behavioural symptoms. Since there is considerable diagnostic overlap with a variety of medical and psychiatric conditions, a careful history of a patient’s substance use, associated problems, and familial patterns of substance misuse is important.

Epidemiology and aetiology—alcohol use is widespread in Europe and North America, with about 1 in 10 people meeting the criteria for alcohol dependence during their lifetime. Genetics, comorbid psychiatric illness, personality factors, and environmental/social factors all influence the likelihood of development of alcohol and drug use disorders.

Pathological effects—alcohol consumption affects virtually every major organ system, with the primary causes of excess mortality including liver disease, severe respiratory infections, cancer of the upper respiratory and digestive systems, cardiovascular disease, suicides, and violence. While drug use is also associated with increased pathology, these effects are often the result of methods of administration or lifestyle rather than direct drug toxicity. Heavy or binge alcohol use during pregnancy can result in fetal alcohol syndrome, the leading preventable cause of mental retardation in North America and Europe. Other common adverse infant outcomes from both alcohol and drug use include reduced birth weight, decreased cognitive and learning abilities, and behavioural problems.

Management—this must focus on both management of the acute withdrawal syndrome associated with discontinuation of regular alcohol or drug use and long-term maintenance of abstinence/sobriety. (1) Alcohol withdrawal management—benzodiazepines remain the mainstay, with flexible, symptom-driven dose protocols appearing to provide greater relief at lower overall medication doses compared with more traditional, fixed-dose regimens. (2) Opioid withdrawal management—buprenorphine, typically in a sublingual formulation, is used. (3) Stimulant withdrawal management, e.g. amphetamines, cocaine—symptoms are primarily psychological rather than physical; antidepressants and/or noncardioselective β-blockers are sometimes employed but there is mixed evidence of effectiveness. Psychosocial treatments including motivational interventions, cognitive behavioural therapies, and supportive therapies are the primary interventions used in the outpatient setting. There is increasing interest in pharmacotherapies to support alcohol abstinence; naltrexone (oral and depot formulations) and acamprosate are now approved for use in North America and most European countries.

Pain—this is often undertreated in drug abusing patients due to providers’ concerns about medication misuse, hyperalgesia in this patient population, and tolerance to opioid drugs. Acute pain in drug-abusing patients can be successfully managed using the same protocols as with any patient, with the possible exception of the need to use higher medication doses. Chronic pain management can be more complex and requires careful assessment and monitoring by the provider.

Marijuana, nicotine, sedative, hallucinogen, and inhalant use—see Chapter 9.1.