Suicide is haram and a major sin. The one who commits suicide is faced with a warning of eternity in the Fire of Hell, where Allah will punish him with the means that he used to commit suicide. If the suicide is due to mental illness that has had such a far-reaching impact on a person’s reason that he is not aware of what he is saying or doing, if in such a case it so happens that he killed himself, then he will not be with the sinners who have committed the major sin of suicide; rather he will be excused. That is because this person was no longer accountable due to severe mental illness that led to loss of reason.