Any psychotropic drug, be it legal - anxiolytic, tranquillizer, benzodiazepine, neuroleptic - or illegal - street drugs - leads to ill-being, depression and to suicide. See table with side effects of psychotropic drugs – Technical Information/Classification .

A joint is made out of pure cannabis or grass; or hashish mixed with tobacco.
Alcohol is a general term, which covers a wide variety of products:
wine, cider, beer, port, cognac, whisky, vodka are types of alcohol with various rates of alcoholic content ranging from 5 to 90 ° (active principles)
Cannabis works the same way: but when we talk about a joint of grass or hashish, there are more than 100 varieties and its T.H.C. rate (active principles) –ranges from 4% to 35% - goes unnoted.alcools aux taux variés de 5 à 90 degrés ( principes actifs)

The half-life of an active substance is the time required by a healthy body, with no previous drug use, to eliminate 50% of the absorbed substance. In the case of cannabis, the half-life is 96 hours or 4 days. This means that within 4 days the body has eliminated 50% of the initial dose. 4 days later, there will be 25% of the product left… Within 28 days, cannabis will be totally eliminated from the body of a person who has not consumed it regularly. Traces of decayed THC may be found in a regular consumer’s body up to 40 days after the last take. According to Dr Chamayou’s thesis, 18 months are needed to be completely cleared of cannabis.

Yes, Alcohol is a sedative drug. In drinking regularly a large amount of alcohol, one becomes an alcoholic within a few years. Alcohol is characteristically able to potentialize the effect of all other drugs it is mixed with. If one mixes alcohol with another or others drugs, one can very rapidly become a drug-addict.