I’m not Roman Catholic, but a Reformed Protestant, and I am not so sure that we should easily go the “mental illness/depression” route. Scripture is clear that things like suicide (ie. self murder) are sins that come clearly from the heart.
How can this come from the heart when a person can be so totured by some inner demons that they cannot think rationally? I had this happen in my own family just 28 dags ago. Nobody but God knows why!
I find it amazing that other illness's no one doubts, but anything that has to do with the brain is somehow not really an illness...Too many people fear such things and therefore poo poo it...Be careful my friend...
Excerpts from the 1907 Catholic Encyclopedia; ( http://www.newadvent.org/cathen/14326b.htm ) The teaching of the Catholic Church concerning the morality of suicide may be summarized as follows:
...God has reserved to himself direct dominion over life; He is the owner of its substance and He has given man only the serviceable dominion, the right of use, with the charge of protecting and preserving the substance, that is, life itself. Consequently suicide is an attempt against the dominion and right of ownership of the Creator. To this injustice is added a serious offense against the charity which man owes to himself, since by his act he deprives himself of the greatest good in his possession and the possibility of attaining his final end. Moreover, the sin may be aggravated by circumstances, such as failure in conjugal, paternal, or filial piety, failure in justice or charity, if by taking his life one eludes existing obligations of justice or acts of charity, which he could and should perform. That suicide is unlawful is the teaching of Holy Scripture and of the Church, which condemns the act as a most atrocious crime and, in hatred of the sin and to arouse the horror of its children, denies the suicide Christian burial. Moreover, suicide is directly opposed to the most powerful and invincible tendency of every creature and especially of man, the preservation of life. Finally, for a sane man deliberately to take his own life, he must, as a general rule, first have annihilated in himself all that he possessed of spiritual life, since suicide is in absolute contradiction to everything that the Christian religion teaches us as to the end and object of life and, except in cases of insanity, is usually the natural termination of a life of disorder, weakness, and cowardice.
..... The Frequency of Suicide and its Chief Causes
The plague of suicide belongs especially to the period of decadence of the civilized peoples of antiquity, Greeks, Romans, and Egyptians. The Christian Middle Ages were unacquainted with this morbid tendency, but it has reappeared at a more recent period, has developed constantly since the Renaissance, and at present has reached such an intensity among all civilized nations that it may be considered one of the special evils of our time.
This suicide rate obviously includes suicides attributable to mental illness, but we cannot accept the opinion of a large number of physicians, moralists, and jurists who, led into error by a false philosophy, lay it down as a general rule that suicide is always due to insanity, so great is the horror which this act inspires in every man of sane mind. The Church rejects this theory and, while admitting exceptions, considers that those unfortunates who, impelled by despair or anger, attempt their life often act through malice or culpable cowardice. In fact, despair and anger are not as a general thing movements of the soul which it is impossible to resist, especially if one does not neglect the helps offered by religion, confidence in God, belief in the immortality of the soul and in a future life of rewards and punishments.
Obviously, you've never experienced something like an intense panic attack.