Just taking the other side. If all of these people were on anti depressants, they would have to have gone to a doctor to get them prescribed, correct? That being the case, is it fairer to say that all of these people were diagnosed clinically depressed and that is the main link? Of course (in this country at least) everyone clinically diagnosed with depression from a shrink would be on anti depressants. Not sure if the cause/effect relationship is good here...
To make matters worse, most antidepressants have significant side effects such as causing a disruption of sleep patterns, sexual side effects, eating and digestive troubles, nausea, lethargy, etc. These side effects can cause as much or in some cases more troubles for the patient than the original condition, so many patients stop taking their meds after awhile or take them intermittently, longing as they do for the feeling of 'normalcy' away from the side effects.
All of these factors and more combine to make this entire issue a very complex one, and some of these meds have been directly linked to suicides in some patients, and profound personality changes.
From what I've seen, I believe that the wrong combination of drugs in the wrong person could indeed send them 'over the edge' but I've also seen many patients who have been able to live much happier lives as a result of a chemical imbalance being corrected through drugs. Getting it right for every patient is something that everyone involved with healthcare want so see, but it's not always possible.