Cannabis is a drug that comes from the cannabis sativa plant. Cannabis is a 'depressant' drug. Depressant drugs do not necessarily make you feel depressed. Rather, they slow down the central nervous system. They slow down the messages going to and from the brain to the body.
Cannabis can also have mild hallucinogenic effects.
Forms of cannabis Marijuana is the most common and least powerful form of cannabis. It is the dried leaves and flowers of the plant. Its texture can be fine or coarse. It can contain seeds and twigs from the plant. The flowers or 'heads' are the most potent part of the plant and so the potency of marijuana will depend upon the amount of leaf and heads it contains.