[Cholesterol, omega-3 fatty acids, and suicide risk: empirical evidence and pathophysiological hypotheses]

Studies in psychiatric patients described an association between lower serum cholesterol concentrations, suicidality, depression, impulsivity, and aggression which is not entirely attributable to depression-related malnutrition and weight-loss. Several lines of evidence suggest that a serotonergic deficit in the prefrontal cortex may predispose vulnerable subjects to impulsive, autoaggressive, and suicidal behaviour in stressful life-events. In-vitro studies, animal experiments, and human in-vivo studies support the hypothesis that cholesterol reduction may contribute to the serotonergic abnormalities which have been postulated in suicidal subjects. Recently it was hypothesized that decreased consumption of polyunsaturated fatty acids, especially omega-3 fatty acids, may be a risk factor for depression and suicide. Data from human studies in healthy volunteers suggest that increasing the dietary intake of omega-3 fatty acids may increase central serotonergic activity and reduce impulsive and aggressive behaviours. Earlier epidemiological studies showed an association between low cholesterol concentrations and increased suicide risk. Recent epidemiological studies with greater samples and longer follow-up periods, however, even showed a positive correlation between cholesterol concentrations and suicide risk after controlling for potential confounding variables. Large trials of statins (simvastatin, lovastatin, pravastatin) did not show an increase of suicide mortality.