The distinction between medicines and sensual drugs is simple. Sensual drugs are those that our body has no use for, but they give the user a strong sense of pleasure. Sensual drugs activate the brain's pleasure centres. We do not know precisely how they do this.

The brain governs sensations, moods, thoughts, and actions, not by a magical process, but by an incredibly complex series of chemically regulated controls. These are easily upset by sensual drugs. The drug user's craving for the drug continues, but he gets less and less satisfaction. His brain's pleasure reflexes seem to be weakened by artificial stimulation. In severe addiction the pleasure mechanisms fail to respond to drug stimulation. The drug then gives only relative relief from misery and suspends the illness of withdrawal. The drug addict experiences a general feeling of discomfort and his personality changes. He feels depressed and does not respond to his environment or the other people. His mental disturbance is similar to paranoia. He has difficulty in discerning the source of his problem. Any thing external is suspect, he draws further and further into himself. The addict often thinks that people are looking at him strangely. He fails to understand things properly.

The drug addict often overlooks the consequences that he will have to face. Possible results range from incidental delirious effects to death from overdose. Drugs act directly on the brain and cause mental mechanisms to respond abnormally. Drug-related health disorders are many and varied. Dirty needles and solutions used for injecting drugs can cause abscesses in the arms and veins, liver disease, AIDS and infection of the kidneys and brain. Sniffing cocaine and amphetamines can damage the tissue of the nose. Babies of women addicted to opiates are likely to be born addicted and to suffer from withdrawal symptoms. A drug user's way of life makes him more susceptible to pneumonia, tuberculosis, malnutrition and weight loss.

Drug-addiction and drug-trafficking have become very serious problems in several countries. Fifty thousand policemen have been appointed lately to deal with the cases relating to drug-trafficking is the USA. A number of clinics have been opened for the treatment of the drug addicts there. In the Gulf countries and some other countries those who are engaged in drug-traffic are given capital punishment. When a country experiences difficulty in arresting a drug-trafficker, the government of that country often seeks the help of Interpol (International Criminal Police Commission) which was established in 1923 (with headquarters in Paris) to coordinate the police activities of the participating nations.