Cannabis cigarette. Hands crumbling cannabis resin (marijuana or hashish) into rolling tobacco, to make a cigarette or joint. Marijuana is made from cannabis (Cannabis sativa) or hemp plant leaves & flowering tops. It is an illegal drug in most countries. Smoking cannabis can cause mental relaxation, perceived slowing of time and heightened senses. Large doses may result in panic attacks and illusions. Prolonged use may lead to sterility, lung damage and psychological problems. Smoking marijuana can help to relieve the symptoms of multiple sclerosis, a disease of the central nervous system. However, medicinal use remains both controversial and illegal.