They say, "hurt people hurt people." True. What is also often true, "Hurt people self-medicate." That is, they're trying run from a problem they otherwise can't mitigate or remedy.

I suppose that can be construed as eventually leading to "loneliness and isolation", but I'm not so sure that's what the writer is talking about. Do we have societal issue that encourage (?) use and abuse? Yes, obviously. But is that what's driving addiction?

It teaches us that many psychiatrists are badly educated enough that they will write laudatory essays about results that don't replicate as long as the original results were appealing enough, and never mention that.