These definitions are based on WHO recommendations and ICD-10.

Acute intoxication

A transient condition following the administration of a psychoactive substance, causing changes in physiological, psychological or behavioural functions and responses.

Dependence syndrome

The use of psychoactive substances has a higher priority than other behaviours that once had higher value. There is a desire, often strong and overpowering, to take the substance(s) on a continuous or periodic basis. Tolerance may or may not be present.

Harmful use

A pattern of psychoactive substance use that is causing damage to physical or mental health.

Physical dependence

An adaptive state in which intense physical disturbance occurs when the administration of a psychoactive substance is suspended. There is a desire to take the substance to avoid the physical symptoms of the withdrawal state.

Psychological dependence

A psychoactive substance produces a feeling of satisfaction and a psychological drive that requires periodic or continuous administration of that substance to produce pleasure or to avoid the psychological discomfort of its absence.

Tolerance

The desired central nervous system effects of a psychoactive substance diminish with repeated use, so that increasing doses are needed to achieve the same effects.

Withdrawal state

Physical and psychological symptoms, which may be complicated by delirium or convulsions, occur following absolute or relative withdrawal of a psychoactive substance after its repeated use.

ALCOHOL PROBLEMS

The concentration of alcohol in beverages may be given as a ‘proof’. In the USA 1° proof is 0.5% by volume (v/v). In Britain 1° proof is 0.5715% by volume.

One unit is approximately 8–10g alcohol (Fig. 4.1).

B9780702028762500044/f04-01-9780702028762.jpg is missing

Figure 4.1

Alcoholic beverages and units of alcohol.

(With permission from Puri BK, Laking PJ, Treasaden IH 2002 Textbook of psychiatry. Churchill Livingstone, Edinburgh.)

Types of alcohol problem

Excessive consumption

The Royal College of Physicians has defined low-risk levels of consumption as up to 21 units of alcohol per week for men and up to 14 units per week for non-pregnant women. This amount should not be consumed in one go, and alcohol should not be consumed every day, for these levels to apply. Consumption in greater amounts is regarded as excessive and carries a much greater risk of developing alcohol-related disabilities and dependence.

Alcohol-related disabilities

Physical complications of excessive alcohol consumption include gastrointestinal disorders, malnutrition, hepatic damage, pancreatitis, hypertension, arrhythmias, iron-deficiency anaemia, macrocytosis, folate deficiency, nerve and muscle disorders, accidents and trauma, increased risk of infections (e.g. tuberculosis) and increased risk of cancer of the oropharynx, oesophagus, pancreas, liver and lung. Drinking in pregnancy can cause the fetal alcohol syndrome.

Psychiatric complications include depressed mood, suicide, personality changes, short-term amnesia (blackouts), alcoholic hallucinosis (auditory hallucinations in clear consciousness), psychosexual disorders, delusional (pathological) jealousy, fugue states, gambling, the use of other psychoactive substances, the amnesic syndrome, dementia and withdrawal symptoms such as delirium tremens and withdrawal fits.

Alcohol-induced amnesic syndrome is frequently preceded by Wernicke’s encephalopathy, caused by thiamine deficiency, which may be reversible in its early stages through abstinence and high-dose thiamine treatment. Its features include:

• Ophthalmoplegia

• Nystagmus

• Ataxia

• Clouding of consciousness

• Peripheral neuropathy.

Social complications include the breakdown of relationships, marriages and families (because of mood changes, personality deterioration, verbal abuse, physical violence, psychosexual disorders, delusional jealousy, and associated gambling and illicit drug use), poor performance at work, crime (e.g. arson, sexual offences and homicide) and accidents and trauma (e.g. road accidents).

Problem drinking

This is said to occur when chronic heavy drinking causes alcohol-related disabilities.

Alcohol dependence

The following symptoms form the alcohol dependence syndrome:

• Primacy of drinking over other activities

• Subjective awareness of a compulsion to drink and difficulty in controlling the amount drunk

• A narrowing of the drinking repertoire

• Increased tolerance to alcohol

• Repeated withdrawal symptoms

• Relief or avoidance of withdrawal symptoms by further drinking

• Reinstatement of drinking after abstinence.

Epidemiology

Indices of alcohol consumption

Useful indices are figures for hepatic cirrhosis mortality (Fig. 4.2), drunkenness offences (including drink-driving offences), psychiatric hospital admissions for alcohol abuse, and surveys.