Novel genetic links to depression discovered in East Asian population

Genetic risk factors for depression are different in East Asian populations compared to European, a new study has shown.

Historically, most studies on the genetics of depression have been based on participants of European descent. However, this study found that East Asians have genetics underlying depression which are different to Europeans, suggesting that findings of studies based on only European populations may not be generalisable to all populations.

'We were surprised to find many differences in the depression genes for Europeans and East Asians, which shows the need to increase the diversity of samples in these types of studies and to be cautious about generalising findings about genes in causing depression,' said study lead Dr Karoline Kuchenbäcker from University College London (UCL).

Depression affects around 300 million people worldwide and is a leading cause of ill health and disability. Previously, 102 genetic variants have been identified that are associated with depression. However, the scientists at UCL have extended their research to non-European populations with the aim to identify further genetic variants that are specific to different ancestry groups.

Using genome-wide association analysis the scientists combined data from multiple studies of people from East Asian descent, a total of 194,548 participants, making it the largest cohort of non-European participants ever studied for genetic risk of depression.

Publishing their findings in JAMA Psychiatry, five new genes were identified which increase depression risk in East Asians. Only 11 percent of variants identified in previous studies, based on only European participants, were associated with depression in East Asian participants. Furthermore, the study found East Asians with higher body mass index have a lower risk of developing depression, the opposite of the correlation previously found in European populations.

Thus, the authors stress the importance of diverse populations for genetic studies of depression. Professor Kuchenbäcker said, 'Genetic research has the potential to contribute to new treatments. But if the foundational research did not involve appropriately diverse study populations, then new treatments might not work the same for everyone, and may contribute to health disparities.'