Analyses of suicide have shown that the most common contributing factor is mental illness, but of the broad range of mental illnesses only a few display a close link to suicide. Among these are depression, bipolar disorder, schizophrenia, borderline personality and antisocial disorders, alcoholism, and drug abuse.
分析自殺原因，最常見的因素就是精神疾病，不過在各類精神疾病中，只有幾種與自殺有強烈關聯，如憂鬱症和躁鬱症、精神分裂、邊緣型和反社會型人格疾患、酗酒和藥癮者等。