Thinking about (completed) suicide

Suicide is a major cause of mortality, and research over the last 50 years has identified many factors found to accompany both suicide-associated behaviors and completed suicide. Why then, has accurate assessment and prediction of suicide risk remained such an intractable clinical problem? Part of the answer is that weak predictors and relatively low base rate combine to impair predictive accuracy. Another factor is that, despite many studies, it has proven very difficult to study suicide prospectively, such that proxy endpoints such as suicidal ideation or parasuicidal behaviors must often be relied upon.