A recent study has revealed that females carry a significantly higher genetic risk for major depression compared to males. This research, which is the largest of its kind, involved approximately 200,000 individuals diagnosed with depression across Australia, Europe, the UK, and the US. Scientists discovered nearly twice as many genetic indicators for depression in the DNA of females than in males.

The study identified around 7,000 genetic variations that could lead to major depressive disorder in both sexes. Additionally, it found about 6,000 variations that are specific to females. The findings, published in the journal Nature Communications, aim to inform more personalized treatment approaches for depression.

Research has consistently shown that women are twice as likely to experience depression in their lifetimes compared to men. The study's authors noted that males and females also exhibit different symptoms of depression. Females tend to show symptoms such as weight gain, excessive daytime sleepiness, and increased appetite. In contrast, males are more likely to display anger, aggression, risk-taking behaviors, and substance abuse.

Neuro-geneticist Jodi Thomas, who led the study at QIMR Berghofer, highlighted that the genetic factors linked to depression in females overlap significantly with those associated with metabolic traits. "That's an interesting finding that we can … continue on the road and see if perhaps therapeutics that are targeting more of these shared signals between depression and metabolic traits may be very good treatments for females," Dr. Thomas stated.

Dr. Thomas emphasized that the genetic findings do not negate the impact of life experiences on the development of major depression, particularly the increased risk of sexual abuse faced by females. "We know that depression is caused not only by genetics, it also has a very large environmental influence," she said.

The researchers made their results publicly available for further analysis by other scientists. Dr. Thomas and her colleague, Dr. Brittany Mitchell, a senior researcher at QIMR Berghofer's Genetic Epidemiology Laboratory, expressed hope that this study will inspire similar research into other health conditions, taking sex differences into account.

"Traditionally, a lot of research, particularly on health conditions, has really focused on males," Dr. Thomas noted. "This leaves a really big gap in our understanding of female health."

The study analyzed the DNA of about 130,000 female participants with major depression and nearly 65,000 males diagnosed with the disorder. The researchers compared this data to nearly 160,000 females and over 132,000 males without a depression diagnosis. Dr. Thomas explained that they conducted various analyses to ensure the reliability of their findings, acknowledging that males are often less likely to seek help or disclose depressive symptoms, which can lead to underdiagnosis.

Clinical psychologist Luke Martin, who was involved in the study, emphasized the importance of these findings in understanding the genetic underpinnings of depression and the need for tailored treatment options for different sexes.