Psychiatrists have always maintained that there is a relationship betw
een aggressive behaviour and suicide in depressed patients. However, t
his relationship is based on inconsistent and undocumented hypotheses,
not on reliable clinical experimental data. The present study was des
igned to investigate the relationship between aggressive behaviour ass
essed by means of the Buss and Durkee Hostility Inventory (BDHI), and
suicide in a sample of 134 depressed out-patients. The group with a hi
gher level of suicidal behaviour was of younger age. The association b
etween depressive subtypes (major depression, recurrent; major depress
ion, single episode; bipolar disorder, depressive episode; dysthymia)
and suicidality was found to be statistically significant. In contrast
, there was no correlation between depressive subtypes and aggressive
behaviour. The relationship between suicide and guilt as measured by t
he BDHI suggests that, in depression, suicidal behaviour becomes part
of a symptom pattern in which aggression does not appear to be the mai
n component. The suicide dimension arises when the cognitive sphere is
involved. In fact, in depression, suicide is included among the cogni
tive disturbances, together with guilt, paranoid and obsessive-compuls
ive symptoms, depersonalization/derealization and agitation.