Genetic link To Premenstrual Depression

A specific genetic variation may be tied to an increased risk for severe premenstrual depression, scientists at the University of North Carolina at Chapel Hill and the National Institute of Mental Health have found.

Known medically as premenstrual dysphoric disorder, or PMDD, this psychiatric condition affects roughly 8 percent of women in their childbearing years. It’s characterized by bouts of major depression and/or anxiety and severe irritability during the second half of the menstrual cycle. Symptoms subside with the onset of each menstrual period.

While PMDD has been thought to be linked to hormonal changes over the course of the menstrual cycle, until now an explanation for the susceptibility to hormone-related mood changes has been elusive.

The team discovered four specific genetic variants, called single nucleotide polymorphisms (SNPs), in one of the two genes that encode the estrogen receptor. The variants, which are differences in strings of DNA nucleotides A, G, C, or T, were identified in the estrogen receptor alpha gene, ESR1.

Compared to the control group, women with PMDD were significantly more likely to have the ESR1 gene variants, the study found.

“While these are preliminary findings that require replication in larger studies, we would argue that this may explain part of the variance among women in the susceptibility to developing this mood disorder,” Dr David R Rubinow, thestudy’s senior author said. “Studies have shown that PMDD is characterized by abnormal sensitivity to reproductive steroids like estrogen.”

The study acknowledges that as with other complex genetic disorders, the contribution to PMDD of polymorphisms in a single gene may not be large. In addition, they also noted that the findings may be telling us more about the control group.

These women, who have no history of psychiatric problems or menstrual cycle-related symptoms, may have gene variants that protect against PMDD. According to Rubinow, “this is equally interesting because it may help us to understand resilience and protection, which are also very important.”

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