Do you mean legally or is your question "Are humans physically capable of committing suicide without a mental disorder"? I don't think that only people with mental disorder can commit suicide. If you have time to read, download this: http://www.suicidenote.info/ It's a book in which a perfectly happy 35 year-old person with a bachelor in psychology attempts to explain why suicide is the only thing that makes sense. That is called nihilism Btw, I'm curious of what @Stingray makes of that. The arguments against Nihilism were never 'logical' but rather 'moral' or 'practical'. Personally, I can't really argue with much of what Michael (the 35yo) wrote. PS: If you are depressed or have any suicidal inclinations atm, DO NOT read that book.