I've personally been excluded from several depression clinical trials for having suicidal ideations, it makes me wonder just what kind of "depression" they are testing drugs on.
Or the type of depression that doesn't lead to suicide ideation because depression, in and of itself, is an incredibly broad term and not everyone that is depressed wants to die.
The type of person who doesn't have suicidal ideations are on the low end of the pool. They are the type of depressed people that things like hanging around friends, going outside, or eating a diet that's not poo works on.