Previous studies have suggested that impulsive and violent behaviour are related to alterations of cholesterol serum concentrations. The primary aim of our study was to find out if there is a difference in cholesterol levels of criminal offenders who act in an impulsive and violent way, and criminal offenders who act non-violently and with persons with no criminal record. The study compares three groups. Impulsive violent criminal offenders (N=21), criminal offenders who commited nonviolent crimes (N=21) and control group included persons with no criminal record (N=21). The analysis of variance (ANOVA) was used to analyse differences in cholesterol levels in all groups. A statistically significant lower level of cholesterol was found with the group of violent criminal offenders, related to the second and the control group. Our findings are therefore consistent with the theory that low levels of cholesterol are associated with increased impulsiveness and aggression, and that they contribute to a more violent pattern of behaviour.

        Key words: cholesterol, violence, depression, suicide, impulsivity, serotonin.