Korean Journal of Biological Psychiatry

An association of low total cholesterol in blood with psychiatric diseases and suicidal behavior has been suggested. As part of an attempt to further explore this relationship, we examine first, whether serum cholesterol levels in psychiatric patients with suicidal attempt would be lower than in non-suicidal psychiatric inpatients or normal controls, second, whether such significant difference of cholesterol levels would be present when the diagnostic groups are analyzed separately, third, whether low cholesterol level would be associated with a history of serious suicidal attempts, and finally, whether low cholesterol level in suicide attempters is a state or a trait marker. We determined the serum cholesterol levels in 231 patients admitted to an emergency room following an suicidal attempt, in the same numbers of age-, sex- and diagnosis- matched non-suicidal psychiatric controls, and in the same numbers of age-, sex matched normal controls. The seriousness of an attempt was divided into 5 grades according to the degree of the resulting medical injury. Total cholesterol levels in suicide attempters were significantly lower compared with both psychiatric and normal controls, when sex, age, and nutritional status (i.e., body mass index) were controlled for. This significant relationship was observed in major depressive disorders and personality disorders, but not in schizophrenia and bipolar type I disorders. The severity of suicide by a lowering of blood cholesterol was related to the magnitude of the cholesterol reduction. After treatment of their psychiatric ailments, the cholesterol levels in suicide attempters were significantly increased. This result suggests that low cholesterol level in psychiatric patients might be a potential biological marker of suicide risk. It is hypothesized that low cholesterol levels is associated with the suicide by modifying the serotonin metabolism, the production of interleukin-2 and melatonin metabolism in psychiatric patients.

Keywords Cholesterol;Depression;Suicide.