Intoxication is a condition that follows the administration of a psychoactive substance and results in disturbances in the level of consciousness, cognition, perception, judgement, affect, or behaviour, or other psychophysiological functions and responses. The disturbances are related to the acute pharmacological effects of, and learned responses to, the substance and resolve with time, with complete recovery, except where tissue damage or other complications have arisen. The term is most commonly used with regard to alcohol use: its equivalent in everyday speech is "drunkenness". Alcohol intoxication is manifested by such signs as facial flushing, slurred speech, unsteady gait, euphoria, increased activity, volubility, disorderly conduct, slowed reactions, impaired judgement and motor incoordination, insensibility, or stupefaction.
Intoxication is highly dependent on the type and dose of drug and is influenced by an individual's level of tolerance and other factors. Frequently, a drug is taken in order to achieve a desired degree of intoxication. The behavioural expression of a given level of intoxication is strongly influenced by cultural and personal expectations about the effects of the drug.
Acute intoxication is the term in ICD-I0 for intoxication of clinical significance. Complications may include trauma, inhalation of vomitus, delirium, coma, and convulsions, depending on the substance and method of administration.
ICD-10 Clinical description
A transient condition following the administration of alcohol or other psychoactive substance, resulting in disturbances in level of consciousness, cognition, perception, affect or behaviour, or other psychophysiological functions and responses.
This should be a main diagnosis only in cases where intoxication occurs without more persistent alcohol- or drug-related problems being concomitantly present. Where there are such problems, precedence should be given to diagnoses of harmful use, dependence syndrome, or psychotic disorder.
ICD-10 Diagnostic criteria for research
Acute intoxication is usually closely related to dose levels. Exceptions to this may occur in individuals with certain underlying organic conditions (e.g. renal or hepatic insufficiency) in whom small doses of a substance may produce a disproportionately severe intoxicating effect. Disinhibition due to social context should also be taken into account (e.g. behavioural disinhibition at parties or carnivals). Acute intoxication is a transient phenomenon. Intensity of intoxication lessens with time, and effects eventually disappear in the absence of further use of the substance. Recovery is therefore complete except where tissue damage or another complication has arisen.
Symptoms of intoxication need not always reflect primary actions of the substance: for instance, depressant drugs may lead to symptoms of agitation or hyperactivity, and stimulant drugs may lead to socially withdrawn and introverted behaviour. Effects of substances such as cannabis and hallucinogens may be particularly unpredictable. Moreover, many psychoactive substances are capable of producing different types of effect at different levels. For example, alcohol may have apparently stimulant effects on behaviour at lower dose levels, lead to agitation and aggression with increasing dose levels, and produce clear sedation at very high levels.