Most of the natural and synthetic drugs have been clinically tried to experiment with different conditions as medicines. Many have shown promising results in certain fields or other. But as it happens, these substances are addictive and have side effects that can be way worse to nullify any usefulness.
These narcotics, natural and synthetics have their own stories to tell.
Also known as Magic Mushrooms, and Shrooms popularly, they have been known to reduce the symptoms while in influence, especially that of OCD. But their side effects include anxiety, confusion, incoherence in thoughts and behaviour, paranoia and panic attacks.
MDMA was originally promoted as the cure for PTSD and was effective in the sense that it got you high and hence no stress. Although it's prolonged use, include serotonergic neurotoxicity, memory problems, and other psychobiological problems.
Alcoholism can be treated for a short term with reducing effects and ever increasing side effects inclusive of hallucinations, mental incoherence and a long list of crappy stuff.
To tell the truth, it is actually a horse tranquilizer, and thus too strong for humans. It is often used as chemical handcuffs, and unbreakable. It was studied as the treatment for depression, and sure one can't be depressed if one is practically unconscious.
Stupid, as it may sound, it was medically proven to cure constipation, however, they came to that. And of course, the side effects are a long list of crappy stuff, including premature aging of the skin.
Well, seemingly the only narcotic with so many uses as medicine for so many mental and physical conditions, with research going on over inhibition of cancers as well. Side effects are next to nothing, except prolonged and continuous high dose use, I am talking years here, can lead to memory loss, hallucinations, incoherent mental behaviour.