Class 12 Biology

Drugs and Alcohol Abuse

The commonly abused drugs are opioids, cannbinoids and coca alkaloids. Most of them are obtained from flowering plants. Some are obtained from fungi.


These drugs bind to specific opioid receptors in our central nervous system and in gastrointestinal tract. Heroin is commonly called smack. Chemically, it is diacetylmorphine; which is a white, odorless, bitter crystalline compound. Heroin is obtained by acetylation of morphine. Morphine is extracted from the latex of poppy plant (Papaver somniferum). It is generally taken by snorting and injection. It is depressant and slows down body functions.


These are a group of chemicals which interact with cannabinoid receptors present mainly in the brain. Natural cannabinoids are obtained from the inflorescences of the plant Canabis sativa. The flower tops, leaves and resin of this plant are used in various combinations to produce marijuana, hashish, charas and ganja. It is generally taken by inhalation and oral ingestion. These substances act on cardiovascular system.


Coca alkaloid or cocaine is obtained from coca plant (Erythroxylum coca). It interferes with the transport of dopamine (a neurotransmitter). It is usually snorted. It acts on the central nervous system, and produces a sense of euphoria and increased energy.

Drugs like barbiturates, amphetamines, benzodiazepines, lysergic acid diethyl amides (LSD), and other similar drugs generally used to help patients with mental illnesses. These drugs are often abused by many people.

Adolescence and Drug/Alcohol Abuse

Adolescence is the period of dramatic physical and psychological changes in a person. An adolescent person is at high risk of falling in the trap of drug/alcohol abuse. Common causes are; curiosity, excitement, experimentation, etc.

Addiction and Dependence

Drugs are frequently used because of their perceived benefits. The inherent addictive nature of these substances results in addiction and dependence. Addiction is a psychological attachment to various effects of a substance. So, a person continues to take addictive substance even when he does not need it in the real sense. Tolerance level of the receptors ion our body increases with repeated use of addictive substances. This results in body craving for higher doses. Long term consequences of addiction can be highly devastating.

Prevention and Control

Parents and teachers should take responsibility to identify situations which may trigger unwanted behavior. Parents and teachers should instill self-discipline adolescent persons. Peer pressure should be avoided at all cost. Proper steps should be taken to increase awareness. If the need arises, then profession help should also be taken.