Low cholesterol increases depression
Men with low cholesterol have a higher death rate from injury. Although cholesterol-lowering tends to reduce CHD mortality in certain age groups, there is no evidence that low cholesterol reduces total mortality. In populations with naturally low blood cholesterol there is also a significant death rate from 'non-medical' causes. Why is there this association?
A pilot study into blood cholesterol and depression in schizophrenics found a highly significant interaction between low levels of cholesterol and depression. Extreme lowering of cholesterol with drugs altered the functional state of the 'feel good' hormone, serotonin. The authors suggest that: 'the degree of the low cholesterol combined with its duration might be a risk factor for the development of an abnormal mental state.'[1] Dr A Ryman, writing in the British Medical Journal says: 'Our current understanding of the relation between cholesterol metabolism and psychiatric illness is poor . . . The possibility that a low or falling cholesterol concentration is a marker of risk merits further study.'[2]
A large study at the Cholesterol Center, Jewish Hospital, Cincinnati, Ohio aimed to assess the relation between cholesterol levels and affective disorders such as depression, bipolar disorder and schizophrenia disorder.[3] Cholesterol concentrations below 4.16 mmol/L (160 mg/dL) were much more common in patients with these disorders. When paired with healthy people of a similar sex and age, patients had much lower total cholesterol, LDL and HDL.
Dr M Law added confirmation two years later. He writes: 'treating depression has been shown to increase serum cholesterol concentration. . . . Low serotonin concentrations (which accompany and may cause depression) are, not surprisingly, also associated with low cholesterol, people who attempt suicide have low serum cholesterol concentrations, . . . men with declining serum cholesterol concentrations are particularly likely to commit suicide.'[4]
References
1. Dursun SM, Burke JG, Reveley MA. Low serum cholesterol and depression. BMJ 1994; 309: 273-4
2. Ryman A. Cholesterol, violent death, and mental disorder. BMJ 1994; 309: 421-2
3. Glueck CJ, Tieger M, Kunkel R, et al. Hypocholesterolemia and affective disorders. Am J Med Sci 1994; 308: 218-25.
4. Law M. Having too much evidence (depression, suicide and low serum cholesterol). BMJ 1996; 313: 651-2.
