Assessing the risk of harm to self and the risk of harm to others usually a
re distinct clinical processes. Yet these forms of aggression frequently co
exist, occasionally with lethal outcomes. The author summarizes the literat
ure on co-occurring aggression against self and others. Studies of homicide
-suicide are reviewed first. Studies investigating the risk of co-occurring
aggression against self and against others are reviewed next. The studies
show a strong link between the 2 forms of aggression, etiologically implica
ting depression and other factors. Both types of risk assessment should occ
ur jointly. Guidelines for combined risk assessment, prevention, and treatm
ent are offered.