12th Class Biology Drugs, Drug Dependence, Mental Health Drug Addiction

Drug Addiction

Category : 12th Class

Symptoms and Control

(1) Drugs : Drugs are normally used for the treatment of diseases. The prolonged use of drugs may lead to the dependence of the body on them. This is drug addiction. Some people without any medical advice, start taking drugs and soon become drug addicts. Certain drugs form habit, but some make the body completely dependent upon them.

(2) Addiction : Some persons are unable to bear tensions or think themselves unable to solve the problems of life or due to certain other curious factors start drinking, smoking and taking certain narcotic drugs and feel relief and peace. Gradually this becomes their habit and they are addicted to these things.

Thus addiction can be defined as a physical and mental dependence on any of the above mentioned factors and get temporary relief and feel pleasure.

The common factors are :

(3) Drug Addiction : The compounds used for the cure of the diseases are known as drugs. Certain drugs of specific category are nerve stimulants and depressants. Some of the drugs function as sedative and others act as hallucinogens.

The regular use of such drugs causes the drug addiction in human and they become habitual of these drugs. Drugs such as aspirin and antihistamines when taken with alcohol may have dangerous effects. Including death.

Types of Drugs : These are a large number of drugs on which people become dependent. On the basis of their mode of action on the brain, these drugs are of four types : Sedatives and Tranquillisers, Opiate Narcotics, stimulants and hallucinogens.

(1) Sedatives and Tranquillisers : These drugs depress the activities of the central nervous system. They give a feeling of calmness, relaxation or drowsiness in the body. Their higher doses induce sleep. Tranquillisers lower tension and anxiety without inducing sleep. Examples : barbiturates and benzodiazephines (e.g., Valium).

Barbiturates are synthetic drugs derived from barbituric acid and are called sleeping pills.

(2) Opiate Narcotics : These drugs suppress brain activity and relieve pain. They are called pain killers. Examples opium and its derivatives and some synthetic drugs (e.g., pethidine and methadone).

Opium and its Derivatives : Opium is the extract from the unripe capsules of the poppy plant (Papaver somniferum). It has bitter taste. The opium addict loses weight fertility and interest in work. Its derivatives are morphine, codeine and heroin. Opium derivatives immediately reduce respiratory and cardiovascular activity, constricts the pupils of the eye, reduce the visual activity and cause nausea and vomiting. An overdose leads to respiratory arrest and death. If the supply of the drug is not available, the addicts exhibit terrible “with-drawal symptoms” in the form of muscle cramps, running nose, vomiting and epilepsy.

(1) Morphine and Codeine : These are derived from opium. Morphine is a most valuable analgesic but it causes addiction. Codeine is a mild analgesic but causes no addiction so codeine is commonly used in many medicines and cough syrups.

(2) Heroin (Diacetylmorphine or Diamorphine) : Heroin is formed from morphine by acetylation. It is highly addictive and, therefore, considered most dangerous opiate. It is banned even for medical use. It is used in research. Heroin is taken orally or inhaled or injected. As the heroin addicts are careless about the needles and syringes so they can cause blood poisoning, serum hepatitis and AIDS.

(3) Stimulants : These drugs stimulate the nervous system; make a person more wakeful, alert and active; and cause excitement. The stimulants include caffeine, cocaine and amphetamines.

(i) Caffeine : It is an alkaloid derived from the leaves of tea plant (Thea chinesis), seeds of coffee plant (Coffea arabic) and seeds of Cocoa plant (Theobroma cocoa). Tea plants and coffee plants are shrubs while cacao plants are trees. Caffeine is a mild stimulant and is commonly taken as beverages - tea, coffee, coca and cola drinks. It increases alertness and thought. As it is mild stimulant, it is used in medicines as a cardiac stimulant. Its excessive use causes addiction.

(ii) Cocaine : It is extracted from the leaves and young twigs of the South American shrub Erythroxylon coca. Cocaine is used as local anaesthetic and stimulant. The bad effects are lack of sleep, loss of appetite and hallucination which ultimately lead to damaged mental functions and insanity. The misuse may also produce severe headache, convulsion or death due to cardiovascular or respiratory failure.

(iii) Amphetamines : These are synthetic drugs, which are strong stimulants. Amphetamines are taken by truck drivers and night workers to keep awake. They do not remove fatigue. However, they impair vision and judgement of distance.

(4) Hallucinogens : These drugs change thoughts, feelings and perceptions of an individuals. Hallucinogens (drugs) cause hallucinations (illusion of seeing objects or hearing sounds, etc., not actually present). They include chemicals such as LSD. (Lysergic acid diethylamide), mescalin, psilocybin and products of hemp plant.

(i) LSD (Lysergic acid diethylamide) : It is derived from Ergot fungus. It is most powerful hallucinogen which causes horrible dreams, chronic psychosis, and severe damage to the central nervous system. LSD also brings about chromosomal and foetal abnormalities.

(ii) Products of Hemp Plant : Bhang (hashish), ganja and charas are three drugs obtained from the dried leaves and flowers of the hemp plant (Cannabis indica) commonly called bhang. Another drug Marijuana is derived from another species of hemp plant (Cannabis sativa). Immediately after the intake of these drugs, the pupils of the eye dilate, blood sugar level rises and frequency of urination increases. These drugs are often mixed with tobacco and smoked. Compared to the other drugs, these drugs may appear to be less harmful, but these may lead to the opiates (opium group) addiction. They are dangerous if taken along with alcohol. Some of these drugs (e.g., Marijuana) cause anxiety and may lead to psychosis.

  • Marijuana is Hallucinogen.


Major Groups of Psychotropic Drugs with Examples and Effects

S.No. Type of Drug Examples Effects


Sedatives and tranquillisers (depressant)

Benozodiazephines (e.g., Valium Barbiturates)

Depress brain activity and produce feelings of calmness, relaxation, drowsiness and deep sleep (high doses).


Opiate narcotics

Opium, Morphine, Heroin, Pethidine, Methadone

Suppresses brain function, relieves intense pain.



Caffeine (very mild), Cocaine, Amphetamines

Stimulates the nervous system; makes a person more wakeful, increases alertness and activity, produces excitement.



LSD, Mescalin, psilocybin, Bhang (Hashish), Ganja Charas, Marijuana

Alters thought, feelings and perceptions cause illusions.


Combinations of Drugs : Some drug addicts use mixtures of drugs to have immediate effect. Combination of alcohol and barbiturates causes increased depressant effect. Mixture of alcohol and antihistamines produces marked drowsiness. Combination of alcohol and valium causes increased sedative effect. Mixture of alcohol and marijuana produces decreased coordination and impaired judgement. Combination of alcohol and aspirin causes increased chances of damage to gastric mucosa.


Alcohol-Drugs Interaction





Alcohol + barbiturates

Dramatically increased depressant effect


Alcohol + antihistamines

Marked drowsiness


Alcohol + Valium

Rapid increase in sedative effect


Alcohol + Marijuana or Hashish

Decreased coordination, increased reaction time, impaired judgement


Alcohol + Aspirin

Increased risk of damage to gastric mucosa.


Effect of Drug Addition of Family, Society and Addicts : The drug-users not only themselves suffer from the ill-effects of drug addiction, they also bring miseries to the entire family. Since they get the supply of the drugs from illegal sources, they encourage smuggling and other associated illegal activities, resulting in several other social problems. It is evident that all the drugs affect the central nervous system and their prolonged use causes permanent damage. The body fails to work without the drugs. Ultimately other organs also get damaged, and the drug-users become victims of various diseases. There are several reasons causing drug addiction.

(1) Curiosity : Frequent reference to drugs in newspapers, literature and on radio makes a person curious to have personal experience of the taste of a particular drug.

(2) Peer group pressure : Constant description by friends about the “good feeling” creates a temptation. Such inspiration from friends and peer groups acts as a pressure to start with drugs.

(3) To overcome frustrations and depressions : The desire to get solace or relief from personal problems initiates the use of drugs. The school children who take refuge in drugs are usually lonely, unloved and insecure.

(4) Excitement and adventure : It is natural for the young to look for some exciting work. The intake of drug being illegal satisfies that feeling of excitement and adventure.

(5) Looking for a different world : Some people believe that drugs open up a new world of perception. It increases the ability to appreciate the aesthetic beauties, helps in intellectual enlightenment and creativity.

(6) Desire to do more physical or mental work : Some people use drugs to increase their working power. Many students use drugs to work whole night before examinations. In most cases this leads to mental-breakdown.

(7) Persistent use to get relief from pain : People suffering from pain often take drugs for relief. Such persistent use is sometimes based on medical prescription. This practice makes them addicts.

(8) Family history : Examples of parents of members of the family using drugs act as the most natural stimulant.

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