Depressants include heroin, opium and barbiturates, none of which are party drugs. No-one takes a shot of heroin and then goes out dancing. Stimulants include cocaine, amphetamine and Ecstacy, all party drugs and very much the sort of thing you take before painting the town red. So why is drinking alcohol, a party drug so common that in any randomly chosen night club over 95% of those present will have taken it, classified as a depressant? If it's a depressant, why does it make me feel perky and happy and energetic and social?