Yes, those concerns have been raised. The problem is - any truly effective antidepressant also, paradoxically, can take some people from too depressed to do anything, to just a little less depressed so they have enough energy to kill themselves. Even electric shock therapy can do this - I saw it during my training. Whether Prozac does this more - or whether it just gets a bad rap because it is so widely used, as such an effective anti-depressant (which it is) - really is not clear at all from the data.
