This is plenty of overuse of many types of medical technology - this overuse is not restricted just to antidepressants or Ritalin. I have had plenty of back problems since a bodysurfing accident in 1989. By necessity I have done a lot of reading, tried several types of treatments, talked to many surgeons, chiropractors, and physical therapists.
The Scientology view against antidepressants reminds me of David Sarno's book "Mind Over Back Pain", where he argues that back pain is mostly in your head. Even though I know his absolute view on this is wrong, his philosophy helped me through a back crisis once, so I recognize his opinion has value *in moderation*.
I have had back surgeries in 1989, 1993, and 2004 - they all proved to be 100% helpful, and 100% necessary. While some people endure surgeries that are not needed, or that are more aggressive than needed, there are other people who have avoided surgery even when it could help, and endured pain that could be avoided.
I know people who are taking antidepressants for whom it is a big help. While I don't have personal knowledge of people who are taking them who should not be, I also believe there is overprescribing of these medications.
If you hear anyone giving an absolutist view on one of these medical topics, I would not trust them as your only source of information.