New study reveals why women face significantly higher depression risk than men

"We already know that females are twice as likely to suffer from depression in their lifetime than males," said Dr. Brittany Mitchell, senior researcher at QIMR Berghofer's Genetic Epidemiology Lab.

"And we also know that depression looks very different from one person to another. Until now, there hasn't been much consistent research to explain why depression affects females and males differently, including the possible role of genetics."

The team analyzed genetic data from hundreds of thousands of people, including about 130,000 women and 65,000 men diagnosed with depression. They identified roughly 7,000 DNA changes linked to depression across both sexes, and another 6,000 genetic variations unique to women, for a total of about 13,000 changes.

The study also showed that depression-related genes in women overlap more strongly with those tied to metabolic traits, which may help explain why women with depression often experience symptoms like weight changes or altered energy levels.

The changes in DNA the scientists have identified are genetic differences people are born with, not changes that happen because of life experiences.

Traditionally, most drug trials and therapies are tested on males, but those involved in the study hope their work will translate to a greater clinical understanding of female depression.

Mitchell said the key takeaway is that differences in genetics, and therefore biology, contribute to the differences seen in depression between sexes. 

While the study focused on participants of European ancestry, the team hopes to expand their work to more diverse populations.

"It will be really important for future research to also include a wider variety of other populations to determine whether our findings are also applicable to other populations," Mitchell said.