Psychiatric Implications of Cocaine Use

Substance Induced Psychosis

The abuse of hallucinogenic drugs (e.g. LSD) and stimulants (including cocaine) can give rise to psychological effects listed in Table 1 above. Although the threshold at which an individual might suffer psychotic effects differs, the prolonged use of large quantities may result in a paranoid psychosis, which closely resembles paranoid schizophrenia. The individual may have the following features,

This condition subsides within 1 or 2 weeks of the last administration of the drug, but may last for months.

A detailed history of any drug use will assist in the differentiation between substance induced psychosis and an underlying psychotic disorder that has been precipitated by use of the drug, which is more likely to have been associated with prodromal symptoms and a decline in personal functioning predating the use of the drug. The period of psychosis may be shortened by ‘urine acidification’ procedures, which hasten drug elimination. (Collier et al 1999p.354, Gelder et al 1994 p.288, Bloye et al 1999 p.56 and Gunn et al 1995).

Delirium and Excited Delirium

Delirium is an acute organic mental disorder characterised by an impairment of consciousness, disturbed attention, perception and thinking. Individuals are disorientated and may suffer from visual hallucinations or illusions.

Cocaine intoxication has been associated with ‘excited delirium’, which is a syndrome uniquely associated with chronic stimulant abuse, and is a medical emergency. It has the features listed below, and has been described as a ‘state of mental and physiological arousal, agitation, hyperpyrexia with euphoria and hostility’. (Farnham et al 1997 pp.1107-8). Karch (2000 p.431) describes the syndrome as having 4 sequential stages – hyperthermia, agitated delirium, respiratory arrest and death over a time course of approximately 4-6 hours.

The following features may be present during the early stages of the disorder,

Deaths from excited delirium cluster in the late summer months, and are more common amongst black males who are more likely to be cocaine injectors, and are younger than those who die of cocaine overdoses. (Karch 2000 p.431).

Blood cocaine concentrations are generally in the range of 6 mg/ml, which is twice the therapeutic dose, but are still well below those levels found in fatal cocaine intoxications. The mechanism behind the cause of death in these individuals is not well understood, but could involve autonomic reflexes, arrhythmias or stress during restraint. Exhaustion and postural asphyxia are probably not causal mechanisms because of the lack of overt asphyxial changes seen at autopsy, such as petechial haemorrhages etc.

High levels of circulating catecholamines could cause ventricular tacchyarrhythmias, coupled with cocaine induced myocardial hypertrophy in chronic users, and the effects of stress on levels of hydration and the onset of lactic acidosis could all be contributory factors.

Treatment in the emergency setting may include the use of neuroleptics for sedation. However, it should be noted that ‘neuroleptic malignant syndrome’ patients may present in a similar manner, and the use of these drugs would clearly worsen their symptoms. Some commentators believe that neuroleptic malignant syndrome is actually a variant of excited delirium (Karch 2000 p.431).

The management of excited delirium consists of careful restraint, seclusion and medication, although the use of electro-convulsive therapy (ECT) has also been found to be safe and effective. (Farnham et al 1997 pp.1107-8).

An individual acting in a violent and erratic or bizarre manner usually attracts the attention of the police, and a struggle often ensues. After being restrained (often forcibly), the individual may collapse and die, bringing the police actions into question. Excited delirium and it’s relationship with deaths in custody is thus an increasingly important area of research.

                              Forensicmed.co.uk book store     T-shirt store

© www.forensicmed.co.uk. Richard Jones forensicmed.co.uk , all rights reserved ; this page or any part thereof may not be duplicated without the express written permission of the copyright owner.

This site aims to provide educational resources for medical students in the fields of forensic pathology, clinical forensic medicine, forensic psychiatry and forensic science. All illustrations used are believed to be in the public domain, and royalty free. However, if this is not the case, and you are the copyright holder, I apologise, and will remove the relevant illustrations if required.