All those disorders you listed can become dangerous in the right conditions, and I don't want guns in the hands of someone who feels so inferior that they want to kill their superior. Nor do I want guns in the hands of someone who hates crowds so much that they open fire. Nor do I want someone who becomes so anxious and paranoid that they start thinking everyone is the enemy.

Edit: Having said that, nice post. Always like a person who gives sources.