Are men’s and women’s brains affected by cholesterol in the same way?
New research suggests that high cholesterol, while known to increase the risk of depression in older adults, may affect the mental health of men and women in different ways.
Dr. Marie-Laure Ancelin from the University of Montpellier Hospital in France and her colleagues found that the effects of the two major subtypes of cholesterol altered the risk of depression differently in men and women.
Prior research has clearly demonstrated that problems with blood flow to the brain in older patients influence not only the development of certain types of dementia, but can increase the risk of depression. Strokes or other types of brain injury can cause or worsen depression, and high blood lipid levels can lead to these conditions. Alterations in lipid levels are a known risk factor for depression.
Ancelin and her colleagues identified a group of 1,040 women and 752 men aged 65 years and older, followed their cholesterol levels and screened for depression symptoms over a seven year period. Both high density lipoprotein (HDL- the “good” cholesterol), and low density lipoprotein (LDL- the “bad” cholesterol) levels were assessed. The presence of depression was ascertained either by a diagnosis based on the Mini-International Neuropsychiatric Interview, or by a score of 16 or higher on the Centre for Epidemiology Studies Depression scale.
The researchers found that even after statistical adjustment for other considerations, including physical health, smoking, genetics, and socioeconomic status, gender had an effect on the association between high cholesterol, the type of lipid, and depression.
Men who had low levels of LDL had twice the risk of depression, whereas in women who had low levels of HDL the odds of depression were 1.5 higher.
Furthermore, in men, but not in women, there seemed to be a genetic link between LDL and serotonin metabolism.
The relationship between depression and cardiovascular disease is not clear-cut. Scientists have postulated that the psychological stress of depression may take a toll on the cardiovascular system, or that the converse is true, and chronic illness contributes to depressed emotions. These results are intriguing in suggesting a more direct and possibly even genetic interaction between cholesterol metabolism and neurotransmitters.
The different risks HDL and LDL levels pose in men and women with regard to depression may present some difficult clinical issues, particularly in treating men with high cholesterol. It may be that while decreasing LDL levels in men reduces cardiovascular risk, it could increase the likelihood of mental health problems. Treatment might require careful consideration between each patient and clinician of individual risk-benefit ratios.
Ancelin writes, “Our results suggest that clinical management of abnormal lipid levels may reduce depression in the elderly, but different treatment will be required according to sex. LDL-C serum level seems to be an important biological marker in men, with a narrow range for normal functioning. Above this range, cardio- or cerebro-vascular risk increases and below it, there is increased risk of depression.”
Ancelin’s results are available in the July edition of the journal Biological Psychiatry
Source: Biological Psychiatry