[smt1]

I think a lot of the time, it is a side effect of lifestyle decisions (and/or misuse) that the drug in question can induce, not necessarily the drug itself. For example, amphetamine is prescribed to millions of Americans for ADHD (see, Adderall/Vynanse). However, if one were to for example, have poor sleep hygenine as a result of miuse, the chance of psychosis is high from not getting enough sleep.

There are definitely neurotoxic substances that can induce psychosis or other problems (such as parkinsonianism) but these tend not to be very usable either clinically or recreationally. I think overall, the chance of cardiotoxic or repository depression is more of a common problem with most common recreatioal drugs at common doses.