More info please. Psychiatric hospitals have an ethical responsibility to not discharge a patient who presents a danger to himself or others, and often take these issue to a judge for commitment papers if the patient insists on being released anyhow. Responding to internal stimuli would qualify as a danger to self or others in certain situations but not all. If this individual actually stated he wanted to die or wanted to harm others and was still discharged, seems like a lawsuit against the hospital could be in order. More info please.
