All of your examples could include "too much social interaction" as their primary cause, but seem unlikely to, to me. Just because a suicide isn't caused by lack of social interaction, doesn't mean it automatically was caused by the opposite.
Basically, either you kill yourself, because you see yourself as unfig with society, either because you are too fit for society, at a point you are ready to die for it. The kamikazes are a good example of that.
