Study provides genetic evidence why women possibly twice at risk of depression than men 

A study has found 6,000 gene variants responsible for causing depression among women, in addition to the 7,000 of those shared with men, potentially explaining why the risk is double in women.

A gene variant is a change in the DNA sequence of gene, which can be inherited from parents or arise spontaneously in an individual.

The findings published in the journal 'Nature Communications' show that genetic factors plays a greater role in risk of depression for women than in men.

"We already know that females are twice as likely to suffer from depression in their lifetime than males," author Brittany Mitchell, senior researcher at QIMR (Queensland Institute of Medical Research) Berghofer Medical Research Institute in Australia, 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," Mitchell said.

The study, which screened genetic data of around 1,30,000 women and 65,000 men having depression from Australia, The Netherlands, the UK and US, is the "largest of its kind", the team said.

Data of nearly 1,60,000 women and over 1,30,000 men without depression were also analysed.

The analysis "revealed that all 7,111 causal variants for MDD (major depressive disorder) in males were shared with MDD in females, with an additional 6,133 variants unique to MDD in females and zero variants unique to MDD in males".

The genetic changes associated with depression were found to more significantly overlap with those linked to metabolic traits in women, which "may help explain why females with depression more often experience metabolic symptoms, such as weight changes or altered energy levels," author Jodi Thomas, researcher at QIMR (Queensland Institute of Medical Research) Berghofer Medical Research Institute, said.

The result provides genetic evidence of how depression presents differently between women and men, the team said.

They also emphasised that the identified DNA changes in the study are genetic differences that people are born with, and not caused by life experiences.

"The findings highlight the importance of considering sex-specific genetic influences in studying depression and other health conditions," Thomas said.