yes and no...
in a sense, yes, because they can relax people and there are actually many legal drugs, but even those that are illegal can help people.
For those in depression, a stimulant or a narcotic might do the trick temporarily. For those that are too hyper, a depresant might be helpful.
But yet, theres something just wrong about hearing "Hey nurse, can ya light me up blount?"

besides, drugs can be addictive and can cause brain and other body system damage.
So, like I said, yes and no...