Suicidal behaviour and lipid levels in unipolar and bipolar depression

Evidence for a possible association between a low level of cholesterol and increased suicidal behaviour has accumulated in the recent 3 decades. The present study investigates whether lipid levels can make state-dependent markers of suicidal behaviour in Polish patients with mood disorder recently admitted to a psychiatric hospital owing to an acute depressive episode.

The study was conducted on 223 patients (73 male and 150 female) with unipolar (n=171) and bipolar (n=52) depression. They were interviewed to assess any occurrence of suicidal thoughts, suicidal tendencies and/or suicidal attempts during the 3 months before admission. Laboratory measurements [total cholesterol, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, triglycerides and total lipids] were obtained within 24-72 h after hospital admission.

Suicidal thoughts, tendencies, and attempts were associated with low total cholesterol, LDL cholesterol, and total lipids in both male and female patients, in both diagnostic categories. Triglycerides were significantly lower in male and female patients with suicidal thoughts compared with their non-suicidal counterparts. No association with suicidality was found with HDL cholesterol.

The results of our study support a majority of research showing the association in depressed patients between suicidal behaviour and low levels of total and LDL cholesterol. In addition, the data suggest a similar association with low total lipids, and in some instances, with low triglycerides.