Females carry a much higher genetic risk of major depression than males, new research has found.
While it has been statistically shown females are twice as likely to suffer from depression, this study has for the first time revealed the genetic reasons behind that.
The global study was the largest of its kind and involved about 130,000 females and 65,000 males diagnosed with depression.
Know the news with the 7NEWS app: Download today 
The results showed important genetic differences in how females and males experience depression, with scientists hoping the findings could pave the way for more targeted intervention and treatments.
Genetic factors were found to contribute more to depression risk in females than in males, with the team said to have discovered about twice as many genetic “flags” for depression in the DNA of females compared with males.
“We already know that females are twice as likely to suffer from depression in their lifetime than males,” Queensland Institute of Medical Research (QIMR) Berghofer’s Genetic Epidemiology Lab senior researcher Dr Brittany Mitchell said.
“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 researchers identified about 7,000 changes in DNA that could cause depression in both sexes, and a further about 6,000 DNA changes that could cause depression in females only.
The study also revealed the genetic factors linked to depression overlap more with those associated with metabolic traits in females.
“We found some genetic differences that may help explain why females with depression more often experience metabolic symptoms, such as weight changes or altered energy levels,” fellow researcher Dr Jodi Thomas said.
The researchers were quick to clarify the changes in DNA they had 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, with the QIMR team hoping their work will now translate to a greater clinical understanding of female depression.
“Unpacking the shared and unique genetic factors in males and females gives us a clearer picture of what causes depression, and opens the door to more personalised treatments,” Thomas said.
“The findings highlight the importance of considering sex-specific genetic influences in studying depression and other health conditions.”
The researchers have made their results publicly available, allowing other scientists to analyse them further in the spirit of advancing scientific knowledge in this area.
