Global depression study uncovers 300 new genetic risk factors

Scientists have identified 300 previously unknown genetic risk factors for depression in a landmark study that analysed DNA data from more than 5 million people across 29 countries.

The research, led by the University of Edinburgh and King’s College London, marks a significant departure from previous studies by including participants from non-European backgrounds, who made up one-quarter of the sample.

Published in the journal Cell, the study discovered 700 variations in genetic code linked to depression, with nearly half being newly identified. These DNA variations were found to affect neurons in brain regions controlling emotion.

One hundred of the newly discovered genetic differences were specifically identified through the inclusion of people with African, east Asian, Hispanic and south Asian ancestry, highlighting the importance of diverse sampling in genetic research.

The findings could lead to more accurate prediction of depression risk across different ethnicities and the development of more inclusive treatment options, researchers said.

The World Health Organisation estimates that 3.8% of the global population – approximately 280 million people – experience depression at any given time.

The study also examined more than 1,600 medications’ effects on 308 depression-linked genes, identifying potential new therapeutic applications for existing drugs.

Pregabalin, used for chronic pain, and Modafinil, prescribed for narcolepsy, were found to potentially affect these genes, though researchers emphasised that further clinical trials would be necessary.

Prof Andrew McIntosh from the University of Edinburgh’s Centre for Clinical Brain Sciences said: “There are huge gaps in our understanding of clinical depression that limit opportunities to improve outcomes for those affected”.

While welcoming the research, Dr David Crepaz-Keay from the Mental Health Foundation cautioned against over-relying on genetic factors, emphasising the importance of addressing societal issues like poverty and racism in depression prevention.

Dr Jana de Villiers, speaking for the Royal College of Psychiatrists, praised the study’s global representation and its potential to improve treatment methods for depression.