Suicide is treated very seriously in halacha. According to the Shulchan Aruch, if someone commits suicide, we basically write him off. No sitting shiva, burial outside the Jewish cemetery, etc. However, the community generally tries to find a way to not call it a suicide. There are some rules delineated in Shulchan Aruch that must come together for it to be considered a halachic suicide, and if they do not, one can avoid the unpleasantness. A common way is to say that he was not of sane mind, and therefore his suicide was not suicide. He was mentally unstable, or something like that (in halacha he has to have told someone prior what he intended to so so we know he was aware of what he was about to do, and he had to have been seen performing the whole suicide).

An avreich in Bnei Braq recently committed suicide. The family, or the community decided to have a sefer torah written in the fellow's memory. Realizing it might be a problem to have a Torah written in his memory, perhaps it is simply inappropriate, they decided to ask Rav Chaim Kanievsky.

A group of askanim (why is it always askanim, and not simply family members or the shul gabbai or someone else like that??) went to Rav Chaim Kanievsky to ask.

Rav Kanievsky asked them if he was aware of what he was doing when he committed suicide. When they responded that he was not, Rav Kanievsky said that if he was not aware then it is ok to write the Torah in his memory, whereas had he been aware it would not be proper. (source: Kikar)