Personality traits were assessed in a series of 148 patients classified according to Winokur into depression pure disease (DPD), depression spectrum disease (DSD) and sporadic depression (SD) with the addition of a fourth group: family history positive-others (FH+.O) comprised of patients with psychiatric disorders among first-degree relatives other than those taken into account by Winokur. Personality was assessed by means of a Swedish inventory, the KSP, comprised of 15 subscales assumed to measure relatively stable traits. DSD patients appeared to be most deviant from the other groups in most variables. Statistically significant differences were obtained for the variable socialization, which measures the internalization of social rules on which the DSD patients scored lowest, and variables of aggression on which the DSD patients scored higher than all the others.