I think that rejection of self (acute disappointment in oneself, and a resulting desire to erase one's very being) is a big factor in many suicides, GfS. Japan has always had high quite suicide statistics, and that is largely because suicide is seen in that culture as a legitimate way of restoring personal honor after having "failed"...or of atoning for one's failure. Enormous numbers of their military personnel committed suicide merely over the personal shame of having participated in a lost battle or a failed campaign. These were highly trained and desperately needed men who took their own lives as a form of apology for having let their nation down by losing a battle! Extraordinary. The thing their nation most needed at that moment (from a practical military point of view) was for them to live to fight again another day, but instead they took their own lives. They did it because they were deeply ashamed of themselves and felt they didn't deserve to live.

While many people do commit suicide because they feel that "no one understands", I think that many also do so because they feel like abject failures. Lack of self-esteem is quite common in depressed and suicidal individuals. It can also be found in the manic type who rebounds from extreme confidence at times to the depths of depression at other times.