What causes a person to become suicidal ? For a woman, rape, mental and physical abuse at the hands of "loved ones", such as a husband, father, brother, even her mother or relative, hormone changes, "stresses of life" in this "world" or "system of things".
For a man, taking on a heavy "load" such as a job, abuse at the hands of his wife, a brother, a father, a mother, so that he reaches a state of depression, such as Fred Trump Jr whose brother Donald and father Fred Sr berated him for wanting to learn about aviation instead of running the Trump company, driving him to become an alcoholic and dying at the age of 42 in 1981.(source: The Washington Post, August 8, 2019, article "Trump Pressured his alcoholic brother about his career")
Here is what the Bible says concerning "losing it", as at Proverbs 18:14: "A person’s spirit (or will to live) can sustain him through illness, but who can bear a crushed spirit ?" Proverbs 17:22 states: "A joyful heart is good medicine, but a crushed spirit (losing the will to live) saps one’s strength."(Note: the word spirit as used in the Bible [either the Hebrew ruach or Greek pneuma] means that which is invisible but produces visible results)
So, when a person has something to really look forward to, they can have "a joyful heart", while those who feel that that they are at their "wits end", not knowing what to do, are placing themselves "in harm's way" of a possible suicide. For those then who come to intimately know our Creator, whose name is Jehovah (see Isa 12:2, KJV), they can now have "the real life" (1 Tim 6:19), to "hang their hat on", as an "anchor for the soul".(Heb 6:19)
Of what Jesus taught, James T. Fisher (1864-1951 C.E.), a psychiatrist, had this to say about the psychological value in Jesus’ Sermon on the Mount: “If you were to take the sum total of all the authoritative articles ever written by the most qualified of psychologists and psychiatrists on the subject of mental hygiene—if you were to combine them, and refine them, and cleave out the excess verbiage—if you were to take the whole of the meat and none of the parsley, and if you were to have these unadulterated bits of pure scientific knowledge concisely expressed by the most capable of living poets, you would have an awkward and incomplete summation of the Sermon on the Mount. And it would suffer immeasurably through comparison.”—A Few Buttons Missing, page 273.
Thus, those who read Jehovah's word the Bible daily, without prejudice, can gain an everlasting hope of a paradise earth that will be the home for "meek" ones, and in which suicidal thoughts will never be again.(Ps 37:11, 29; Matt 5:5)
Isaiah 35 gives this promise: "The wilderness and the parched land will exult, and the desert plain will be joyful and blossom as the saffron. Without fail it will blossom; It will rejoice and shout for joy. The glory of Lebʹa·non will be given to it, the splendor of Carʹmel and of Sharʹon. They will see the glory of Jehovah, the splendor of our God. Strengthen the weak hands, and make firm the knees that are shaking. Say to those who are anxious at heart: “Be strong. Do not be afraid. Look ! Your own God will come with vengeance, God will come with retribution. He will come and save you.” At that time the eyes of the blind will be opened, and the ears of the deaf will be unstopped. At that time the lame will leap like the deer, and the tongue of the speechless will shout for joy. For waters will burst forth in the wilderness, and streams in the desert plain........And a (symbolic) highway will be there, yes, a way called the Way of Holiness. The unclean (or abusive) one will not travel on it. It is reserved for the one walking on the way (whose shows genuine love); No one foolish (or heartless) will stray onto it."(Isa 35:1-6, 8)