Hundreds of genes have been newly linked to depression, shedding light on the origins of the condition and highlighting personality types that could be at risk.
The international study published in Nature Neuroscience, involving more than two million people, is the largest of its kind. It could inform treatments for the condition, which affects one in five people in the UK and is the leading cause of disability worldwide. Scientists studied information pooled from three large datasets of anonymised health and DNA records and pinpointed 269 genes that were linked to depression.
They also used an innovative statistical method to identify sections of DNA that were common in people with depression and in those who adopted lifestyle behaviours such as smoking. The findings suggest that depression could be a driving factor leading some people to smoke, but more research is needed to explain why, the team says.
Results also show that neuroticism - a tendency to be worried or fearful - could lead people to become depressed, which could shed light on personality factors that put people at risk.
The statistical approach - known as Mendelian randomisation - allows scientists to look at how a condition impacts on behaviour, while ruling out other influences such as age or income.
Anonymised data, used with donor consent, is held by UK Biobank, the personal genetics and research company 23andMe and the Psychiatry Genomics Consortium. Experts say that the study reflects the importance of data science in understanding mental health and the leading role that Scotland plays in this field. The team is inviting people with depression or anxiety in Scotland to take part in a further study, to understand more about the role of DNA in the common mental health conditions.
The research - known as The Genetic Links to Anxiety and Depression (GLAD) Study - aims to better understand depression and anxiety in order to improve the lives of people with mental health issues. The team, working with colleagues at the National Institute of Health Research Mental Health BioResource and King's College London, hopes to collect saliva samples and questionnaires from 40,000 people across the UK. Participants in the study will be offered the chance to take part in further mental health research.
The study lead said: "These findings are further evidence that depression is partly down to our genetics.We hope that by launching the GLAD study, we will be able to find out more about why some people are more at risk than others of mental health conditions, and how we might help people living with depression and anxiety more effectively in future."
More than 100 genes linked to depression!
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