This is a text of the 19th Deshamanya Nandadasa Kodagoda Oration delivered by Prof. Ravindra Fernando at the Sri Lanka Foundation on August 2

Adrug is a substance when taken into the living organism can modify one or more of its functions. Drug abuse may be defined as the use of a drug, usually by self-administration, in a way different from the approved medical or social patterns in a given culture.

Addiction is a state characterized by behavioural and other responses that always include a compulsion to take the drug on a continuous or periodic basis in order to experience its psychic effects (psychic dependence) and sometimes to avoid the discomfort of its absence (physical dependence).

Alcohol

Alcohol has been produced by humans for over 12,000 years! Alcohol causes impaired judgment, decreased inhibitions, coma and even death. Alcohol causes physical and psychological dependence. It affects the liver, heart, pancreas, stomach and brain.

Barbiturate type drugs

Barbiturates are depressants of the brain. It can cause relief of tension, mental stress and anxiety with positive feelings of pleasure, calmness, and relaxation. Overdose can cause coma, respiratory failure and death.

Amphetamine, methamphetamine (Ecstasy) and anti-obesity drugs

Amphetamines have medical uses for attention deficit disorders, narcolepsy and appetite suppressant (slimming pills). Abuse can cause feeling of well-being, euphoria, increased alertness and energy, improvement of performance, and bizarre, erratic and violent behaviour. 3,4-methylenedioxymethamphetamine (MDMA), also known as Ecstasy, is said to increases all pleasurable sensations. Ecstasy is popular among participants of discos and night clubs and users have died suddenly in night clubs.

Cannabis or marijuana or ganja