I think you’ve hit on a big part of the problem. The availability of these “magic pills” discourages doctors, therapists, and psychologists from taking the necessary steps to make a proper diagnosis. Instead, they can prescribe some magic pills, in a low dosage to start of course, and “see if that helps”. Most people will report some positive effects after a few weeks, because the magic pills are psychological uppers. However, if they report positive effects, lazy doctors can assume that depression was the correct diagnosis, and pat themselves on the back.
Also, the pills do have rare side effects that can provoke psychotic behavior, and I really don’t think that they take any precautions against that. Even if the side effects are very rare, when you prescribe these pills widely to the general public for minor maladies, those very rare events are going to happen more often.
We will probably have a test for the presence of the genes that underlie the condition soon. That test should be mandatory, particularly for anyone running for political office.