Can I file for divorce if my husband is mentally incompetent? 

Question Details:

My husband and I separated 3+ months ago, and I just found out from his parents (where he was living) that he has stopped taking his medication for his schizophrenia. He refuses to get back on them, and i see his mental health is declining. He is now living on the streets. I've had him here sleep on the couch out of guilt but this is not a solution and I am not helping him by doing so. He has asked me to file for divorce in a text message at 1 in the morning. Is he legally allowed under this condition to be signing these types of papers? Important Notice