Also from Edwin S. Shneidman, known as the "father of suicidology," who by the way developed his own interest in the topic from work he did at the V.A. (read his story elswhere, for example in his obituaries, to confirm this) He also also developed the concept of the "psychological autopsy," where you could go back from the point of a person's suicide and attempt to reconstruct the reasons why the person got there/stressors that they found too much to bear.
For educational purposes, here are what he considered the "top ten commonalities of suicide.":
1. The common purpose of suicide is to seek a solution;
2. The common goal of suicide is cessation of consciousness;
3. The common stimulus of suicide is unbearable psychological pain;
4. The common stressor in suicide is frustrated psychological needs;
5. The common emotion in suicide is hopelessness;
6. The common cognitive state in suicide is ambivalence;
7. The common perceptual state in suicide is constriction;
8. The common action in suicide is escape;
9. The common interpersonal act in suicide is communication of intention;
10. The common pattern in suicide is consistency of lifelong styles.
-- Source: The Suicidal Mind, by Edwin S. Shneidman.
