Alcohol, drugs and mental illness

Over-the-counter medicines
A variety of medicines that contain mild mood- altering drugs are available from pharmacies without a doctor's prescription. For example, some cough medicines contain codeine, part of which the body can convert into morphine. Cough and cold remedies also often contain stimulants such as ephedrine. Other cough remedies contain antihistamines, such as promethazine, whose sedative action is increased significantly by alcohol.

Solvent abuse
Solvent abuse (better known as glue-sniffing) is not uncommon because solvents, which are carbon-based substances used in glues, paints, nail varnish removers, aerosols, petrol and cigarette lighter gas, are easily bought over the counter. Solvent vapours are inhaled, passing from the lungs directly to the brain to produce a drunken sensation. The habit seems to be largely confined to secondary school children: surveys show that 7-10 per cent inhale solvents.

A disproportionate number of deaths from solvent abuse are caused by gas fuels (butane) and aerosols rather than glue. Long-term solvent abuse can lead to damage to the brain, kidney and liver. There seems to be no indication that the practice is a cause of schizophrenic relapse. In 1994 alone, 57 deaths in the UK were caused by the inhalation of solvents, adhesives and aerosols; some of the victims were first-time users.

Hormonal drugs
Some medications prescribed for physical conditions can induce psychiatric symptoms. These include steroids, which are used by athletes. In prolonged use or over-dosage, they can produce mood changes of either elation or depression, as well as ideas of persecution. Those with depressive illness should be cautious.

Stimulant substances
The most frequently abused stimulant drugs are amphetamines and cocaine, both of which are illegal. Commonly available drinks such as coffee, tea, cocoa and cola contain the stimulant caffeine, and cigarettes and tobacco contain nicotine. These are all freely available legally and may produce undesirable side effects if taken in excess. These substances stimulate the nervous system, elevate mood, increase alertness and overcome fatigue.