[Aggressive and suicidal behavior. A cluster analysis study of suicidal and nonclinical subjects]

An attempt was made to examine the relationship between different dimensions of aggression and suicidal behavior in clinical and non-clinical subjects.

A clinical sample of 68 suicide attempters (39 females, 29 males) and a matched sample of 70 non-clinical subjects (38 females, 32 males) were subgrouped by cluster analytic techniques. Classification variables included the scales of the Aggressive Factors Questionnaire (AFQ). Discriminant function analyses were performed on the clusters to determine the quality of group separation and to assess the power of each input variable. External variables such as the amount of hopelessness, suicidal ideation and the number of suicide attempts were used to assess the clinical relevance of the identified clusters.

Two subgroups were identified in each sample. Variables that contributed most to group separation were Auto-aggression/Depression and Spontaneous Aggression in the non-clinical sample and Excitability in the clinical sample, respectively. The clusters identified within the non-clinical sample differentiated between ideators and non-ideators. Cluster allocation within the clinical sample was indicative of the number of suicide attempts.

Clusters defined on the basis of different dimensions of aggressiveness turned out to be a classification with significant implications for the assessment of suicidal behavior.