A letter I wrote to a friend:
You have expressed an interest in current legislation regarding euthanasia or assisted suicide.
It may be worth knowing that according to the Minchas Chinuch in 34, suicide is not prohibited to Gentiles.
והנה מאבד עצמו לדעת אינו בכלל לאו דלא תרצח רק חייב מיתה ביד"ש כמבואר בר"מ פ"ב מהל' רוצח ונ"מ אם שיבר כלים בשעת מעשה. גם נ"ל דב"נ אין מצווה דנלמד מאך דמכם לנפשותיכם ולא נישנית בסיני אם כן לישראל נאמרה ולא לבני נח.
According to the MInchas Chinuch, it would hard to make the argument that in Jewish thought suicide is criminally repugnant to the conscience and to society.
From R Ozer Alport in his Parsha Potpourri:
This is discussed at length in:
S’ridei Aish 104, Chovos HaLevavos Shaar HaBitachon, Matamei Yaakov, and Chavatzeles HaSharon
I personally think that is is absolutely assur. Why does the Torah give a reason for the issur retzicha, but not for the other less sichlius issurim? Because the chidush is that murder is not only a crime against the individual, it is a crime against nature, against society, against God. Once the Torah teaches this, then it follows that the issur of retzicha applies no less to suicide.