Why someone commits suicide is often a mystery. But we still wonder.

One highly respected expert who has studied this topic is Kay Redfield Jamison, professor of psychiatry at Johns Hopkins. A few quotes from her 2000 book Night Falls Fast: Understanding Suicide :

Each way to suicide is its own: intensely private, unknowable, and terrible. Suicide will have seemed to its perpetrator the last and best of bad possibilities, and any attempt by the living to chart this final terrain of life can be only a sketch, maddeningly incomplete.  

When people are suicidal, their thinking is paralyzed, their options appear spare or nonexistent, their mood is despairing, and hopelessness permeates their entire mental domain. The future cannot be separated from the present, and the present is painful beyond solace. “This is my last experiment,” wrote a young chemist in his suicide note. “If there is any eternal torment worse than mine I’ll have to be shown.”

It is tempting when looking at the life of anyone who has committed suicide to read into the decision to die a vastly complex web of reasons; and, of course, such complexity is warranted. No one illness or event causes suicide; and certainly no one knows all, or perhaps even most, of the motivations behind the killing of the self. But psychopathology is almost always there, and its deadliness is fierce. Love, success, and friendship are not always enough to counter the pain and destructiveness of severe mental illness.

Another leading researcher on why someone commits suicide is Professor Thomas Joiner, author of several pertinent books. He believes there are three main contributing factors: feeling a burden to others; loneliness and isolation; and lacking fear.

Having a longstanding pattern of substance abuse is one possible way the body becomes inured to self-harm and/or pain. Others, per Todd Kashdan, Psychology Today, include:

• playing violent and extreme sports
• getting multiple body piercings and tattoos
• shooting guns
• getting in physical fights

New Zealand psychologist Jesse Bering‘s 2018 book Suicidal: Why We Kill Ourselves has been written in a uniquely approachable way, according to some reviewers. Bering is a survivor himself of an ongoing battle with suicidal ideation.

Bering’s earlier articles, e.g., his 2010 “What It Feels Like to Want to Kill Yourself” and “Why Do More Men Than Women Kill Themselves” also shed light on the topic, including his personal struggles.

One of the various reasons people consider or commit suicide is depression, of course, but “most people suffering from depression do not kill themselves (only about 5 percent Bering says), and not all suicide victims were depressed.” Genetics and environmental factors can also play a large part in one’s desire to stop living.