Drug and alcohol abuse

The essentials

The drugs commonly abused are opioids, cannabinoids and coca alkaloids, mostly obtained from flowering plants and some from fungi.

• Opioids bind to specific opioid receptors in the central nervous system and gastrointestinal tract. Heroin (smack), chemically diacetylmorphine, is a white, odourless, bitter crystalline compound obtained by acetylation of morphine, which is extracted from the latex of the poppy plant Papaver somniferum. Heroin is a depressant and slows down body functions.
• Cannabinoids interact with cannabinoid receptors, mainly in the brain. They are obtained from the inflorescences of Cannabis sativa; products include marijuana, hashish, charas and ganja. They affect the cardiovascular system.
• Coca alkaloid (cocaine) is obtained from the coca plant Erythroxylum coca. It interferes with the transport of the neurotransmitter dopamine, has a stimulating effect on the central nervous system and causes euphoria; excessive doses cause hallucinations.
• Other plants with hallucinogenic properties include Atropa belladonna and Datura.
• Drugs such as barbiturates, amphetamines, benzodiazepines and LSD, normally used to treat mental illnesses like depression and insomnia, are often abused.
• Tobacco contains nicotine, an alkaloid that stimulates the adrenal gland to release adrenaline and nor-adrenaline, raising blood pressure and heart rate. Smoking increases carbon monoxide in blood, reducing haem-bound oxygen.

Adolescence (about 12–18 years) is a period of biological and behavioural change, and curiosity, peer pressure, the need for adventure and excitement, and family problems can lead to experimentation with drugs. Repeated use leads to addiction and dependence; abrupt stopping causes a withdrawal syndrome. Chronic use of drugs and alcohol damages the nervous system and liver (cirrhosis). Use during pregnancy can harm the foetus.

Key points

• Prevention: avoid undue peer pressure, education and counselling, seeking help from parents and peers, watching for danger signs, and professional and medical help.