Relation between suicide and homicide in Portugal from 1970 to 1982

To evaluate to what extent a suicide can be considered a hetero-aggression converted into self-aggression, this study analyses whether the increase in suicides corresponds to a decrease in homicides and vice-versa. Rates of suicide and homicide from 1970 to 1982 have been analysed in Portugal, Azores and Maderia, and the district and city of Lisbon; age and sex groups have also been compared. There is no inverse variation between suicides and homicides either globally or for males or females. There is also a difference in age distribution for suicides and homicides - suicides being mainly over 50 years, homicides mainly under. This suggests that it is not very plausible that self- and hetero-aggressive behaviours alternate in the same individual, although it is possible that, with increasing age, he may move from hetero- or potential hetero-aggression to self-aggression.