4. Stimulants – Drugs that excite the central nervous system. e.g caffeine, cocaine and amphetamine 5. Tranquilisers – Drugs that change or modify an individual’s emotional state or mood. e.g valium, librum 6. Hallucinogens – Drugs capable of provoking changes of sensation, thinking, distorted perceptions, self – awareness and emotions. They alter the user’s ability…