A study by the University of Edinburgh has found that 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, involving more than two million people, is the largest of its kind.

Scientists analysed health and DNA records, after which they pinpointed 269 genes linked to depression.

Researchers from the Genetic Links to Anxiety and Depression (Glad) Study, identified sections of DNA common in people with depression and in those who took up ‘lifestyle behaviours’ such as smoking. Their findings suggested that depression could be a driving factor leading some people to smoke, researchers said.

They also found neuroticism β€” a tendency to be worried or fearful β€” could lead people to become depressed.

Participants in the study will be offered the chance to take part in further mental health research.

The study, published inΒ Nature Neuroscience, was funded by Wellcome and the Medical Research Council.

Professor Andrew McIntosh, of the University of Edinburgh’s Centre for Clinical Brain Sciences, who led the research, 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.’

Sophie Dix, director of research at mental health charity MQ, who was not involved in the research, said: ‘The power of this big genetic study is that it can point to systems in the brain which adds to our currently limited understanding in this area.

‘By increasing our understanding of these systems, and how the social environment affects biological risk factors, we can begin to identify new targets for treatments that could help the millions of people worldwide affected by depression.’

The study, published in Nature Neuroscience, was funded by Wellcome and the Medical Research Council.

Original study