Major depressive disorder is the term doctors use to officially describe one of America’s most…
Low Levels of BDNF Blamed for Depression in Elderly Women
Recent findings from a team of Japanese researchers link increased major depression risks in elderly women to reduced blood levels of an important human protein known as BDNF.
Researchers and mental health professionals know that women and the elderly are two of the population groups most likely to develop symptoms of major depression or some other depressive illness. In a study published in January 2015 in the journal Progress in Neuro-Psychopharmacology and Biological Psychiatry, researchers from five Japanese institutions looked at the impact that reduced levels of a key protein called BDNF have on elderly women’s major depression risks. These researchers linked low BDNF levels to increased chances for depression in this at-risk demographic group.
Depression and Women
Statistically speaking, 17 women in the U.S. receive a major depression diagnosis for every 10 men who receive such a diagnosis. Biological/hormonal factors help explain part of this stark, gender-based difference. For example, during their childbearing years, women naturally undergo recurring, potentially mood-destabilizing changes in their hormone levels as they move through various phases of the monthly menstrual cycle. At the end of their childbearing years, women also undergo potentially mood-destabilizing hormonal changes associated with the onset of menopause. In addition, pregnancy and the postpartum period following pregnancy make their own contributions to hormone-related depression risks unique to women. Non-biological explanations for women’s magnified exposure to depressive illness include stress associated with a traditionally prominent role in household management, reduced socioeconomic opportunities in comparison to men and a tendency among doctors to diagnose depression in women more quickly than in men.
Depression and the Elderly
The elderly have increased risks for depression that include medication side effects and unintended interactions, increased exposure to physical conditions that limit mobility and self-sufficiency, and increased exposure to mental health conditions that limit self-sufficiency. Symptoms of depression in older people can differ substantially from those found in younger adults and teenagers, the National Alliance on Mental Illness reports. For this reason, doctors may overlook or mischaracterize depression in the elderly. Unfortunately, some people view depression in the elderly as an expected norm, not a pressing mental health concern.
BDNF is the common abbreviation for a protein called brain-derived neurotrophic factor. All healthy human beings naturally produce this protein in their brains and spinal cords, where it serves functions that include growing and maintaining nerve cells, making sure that the brain’s nerve cells maintain the connections that allow them to communicate, and regulating normal functions associated with the control of body weight and the consumption of beverages and food. In its role as a maintainer of nerve cell communication, BDNF is crucial in giving the brain its ability to adapt to changing circumstances.
BDNF and Depression in Elderly Women
In the study, researchers from Japan’s Showa University, Tokyo Metropolitan Institute of Gerontology, Dokkyo Medical University, National Institute for Longevity Sciences and Toho University used information drawn from 538 women between the ages of 78 and 88 to gauge the impact of BDNF levels on the major depression risks of elderly women. All of these women underwent blood tests to determine how much of the protein was circulating in their bloodstreams. Each woman also took two screening tests designed to detect the presence of major depression symptoms. In addition, each woman took a separate test designed to detect potential symptoms of any mood disorder (a category that includes all forms of depression and all forms of bipolar disorder).
Eight of the study participants had test scores that indicated the presence of major depression. Another 45 participants had scores that indicated the presence of some other form of depressive illness. A subgroup of 106 participants had no indication of any type of mood disorder. When the researchers compared the major depression-affected women to the women unaffected by a mood disorder, they concluded that the women with major depression had significantly lower levels of BDNF circulating in their bloodstreams. They also concluded that those women with the lowest BDNF levels had the most severe depression symptoms. Even when the researchers excluded all study participants affected by potentially diagnosable major depression or some other mood disorder, they linked low BDNF levels with increased chances of registering depressive tendencies on the two screening tests.
The study’s authors believe that low BDNF levels, already confirmed as a depression risk in younger populations, apparently also help predict major depression in elderly women.