Well. First off, lots of antidepressants, can’t just be discontinued. The person needs close/frequent contact with a doctor. Some have extreme personality changes, when even minor dosage changes are made. Many of the people they know can be affected, when someone changes the dosage of their antidepressant , or abuses other drugs , in conjunction. So, there’d have to be a way to deal with that. The black market would benefit. Case by case (as stated by the op,) plus close, continuous checking on the patient’s responses to the med , would be ideal. Abuse of such drugs, is rampant though. Same with opioids. And that needs to be assessed, with constructive, unbiased and realistic suggested courses of action, and possible negative effects. I think most drugs should be legal. Just not abused. If the patient isn’t taking a prescribed drug, as directed by the doctor, it could have unforseen effects. But if they took the drugs ,as directed by a competent physician, they might better their lives…