Is it permissible to pray for someone who committed suicide if they were suffering from an unnoticeable mental illness and appeared kind and naive to others?

One prays over a person who committed suicide. It has been reported that the Prophet, may Allah bless him and grant him peace, did not personally pray over a person who committed suicide, as a deterrent to the people, not because it is impermissible to pray over him. The Companions did pray over him, and this is the view of the majority of scholars. Some scholars, however, held the view of not praying over him as a deterrent to others.