Trying to play mind-reader, I will assume you were asking about the legality of removing firearms from a home of someone with PTSD. The short answer (without knowing your state or details) is that simply being diagnosed with some sort of PTSD should NOT be sufficient grounds to seize firearms. However, if the person was involuntarily committed for a psychiatric evaluation, or voluntarily committed for such an evaluation for a period of time (law varies by state) then they could lose their right to possess or own firearms.