Though widely used in clinical and biological studies, no investigation of the factor structure of the Karolinska Scales of Personality (KSP) has been performed in suicide attempters. There are very few studies of personality traits in suicide completers. The aim of the present study was to assess the factor structure of KSP in suicide attempters. A secondary aim was to examine whether the factor structure of the KSP was related to gender and/or to violent method of the suicide attempt or to suicide completion.

The factor structure of the KSP was analysed in data from 165 suicide attempters from the Suicide Prevention Clinic at the Karolinska University Hospital using principal component analysis and orthogonal varimax rotation for the factor extraction. The effect of gender and (1) used method in the suicide attempt (violent versus nonviolent), and (2) later completed suicide on the factors was assessed in two separate series of the two-way ANOVAs.

A four-factor solution appeared: (1) Neuroticism, (2) Nonconformity, (3) Psychoticism and (4) Extraversion. Men who later completed suicide reported more Extroversion than male survivors.

The obtained factor structure is comparable to a previous factor structure in a group of twins from the population-based Swedish Twin Registry indicating that no specific personality structure characterized the current sample. Differences in personality traits between suicide completers and survivors indicate that these groups may have some distinct characteristics.