From what I can tell, the most widely used antidepressants are long off patent and pretty cheap as generics. That’s why insurance companies want doctors to prescribe them instead of sending you to expensive therapy. Overprescribing antidepressants in that sense is more like overprescribing aspirin. Medically unnecessary, maybe even potentially harmful? Maybe. But, the stuff is too cheap for Big Pharma to be doing it purely for the money. That’s what opiods were for ;).