Women carry a higher genetic risk of depression, new study says | Science
Women have a higher genetic risk of depression, a new study revealed.
By claiming to be the biggest genetic study to date on sexual differences in major depression, research published Wednesday in Nature Communications has found 16 genetic variants linked to depression in women and eight in men.
The study, led by the Qimr Berghofer Medical Institute of Australia, has shown that a large part of the variants associated with depression were shared between the sexes, but there was a “higher burden of genetic risk in women who could be due to variants specific to women”.
Dr. Brittany Mitchell, principal researcher at the Qimr Berghofer genetic epidemiology laboratory, said that “we already know that women are twice as likely to suffer from depression in their lives as men”.
“And we also know that depression seems very different from one person to another. So far, there has been no very coherent research to explain why depression affects women and men differently, including the possible role of genetics,” said Mitchell.
The study recognized that the explanations have been put forward covering behavioral, environmental and biological areas, including men less likely to request help leading to a sub-diagnosis, and environmental exhibitions like women being more frequently exposed to sexual abuse and interpersonal violence.
The study said that together, these factors highlight the need for a “multifaceted approach” to understand the underlying mechanisms of depression, but proposed that a “key component of the underlying biological mechanisms for these disparities could be differences in genetics”.
The researchers analyzed the DNA of five international cohorts-Australia, Netherlands, United States and two from the United Kingdom-with a final sample size of 130,471 women and 64,805 men suffering from major depression, and 159,521 women and 132,185 men without diagnosis.
They also found stronger genetic correlations in women between depression and metabolic features (such a body mass index and metabolic syndrome) than in men with the same traits.
Dr. Jodi Thomas, the principal researcher, said that these genetic differences “can help explain why women suffering from depression more often experience metabolic symptoms, such as changes in changed energy”.
The authors acknowledged that the study included about twice as many women with depression as men and carried out additional analyzes to ensure that their results were not due to the difference in samples.
They also recognized the limits according to which their analyzes were limited to Europeans only, which limits the applicability of results to other populations.
Professor Philip Mitchell, from the School of Clinical Medicine of the University of New South Wales, said: “There has been a long-standing debate on the reasons for the constant observation in the world that depression is more frequent in women than men, most studies indicating that women have 2 to 3 times the risk of depression compared to men”.
“The most dominant theories have been linked to social and psychological factors, for example the impact of the female role in the care of families in relation to the role of gain of income for men or personality vulnerabilities in women,” said Mitchell, who was not involved in the study.
“This new very interesting genetic study in a very large global study provides solid evidence that these differences in depression rate can actually be due to genetic factors, with the statistically significant discovery of more regions of risk of depression in genome in women compared to men, and little overlap in these regions between men and women.”
“In addition to the strengthening of evidence that differences in depression rates between men and women can largely be due to biological factors, it also indicates the future possibility of different pharmacological treatments for depression in women and men, as biological systems coded by these genetic regions become better understood.”
