Study finds that depression could be rooted in our DNA

DNA

A new large-scale study has identified 15 genome locations in human DNA that may be associated with depression, leading to a potential breakthrough in understanding the biology behind the mental health condition, which affects 1 in 5 people in the UK.

The team, led by researchers from Harvard and Massachusetts General Hospital, the University of Pennsylvania and backed by US medical research agency the National Institutes of Health (NIH), analysed genotyping data from more than 140,000 individuals of European descent who had a diagnosis of depression, as well as data relating to more than 330,000 others with no history of depression diagnosis.

Publishing in the journal Nature Genetics, the study authors identified 17 genetic variations linked to depression at 15 genome locations, and also found some evidence of overlap between the genetic basis for depression and other mental illnesses, such as bipolar disorder and schizophrenia.

Lead researcher Professor Roy Perlis, associate director of the Psychiatric Genetics Program in mood and anxiety disorders at Massachusetts General Hospital, says: “We hope these findings help people understand that depression is a brain disease, with its own biology.

“Now comes the hard work of using these new insights to try to develop better treatments.”

Woman sitting on bench

The majority of the data for the study was provided by private US-based company 23andMe, who offer a genetic profiling service which – for around £125 – can provide an individual with information relating to more than 100 genetic traits and inherited risk factors for various health conditions, all via a saliva-based DNA home test kit.

23andMe says that the average customer that consents to have their results and medical history anonymously added to data pools for further research could contribute to more than 230 studies, with the aim of learning more about disease prevention, treatments and possibly even future cures.

While experts have long suspected genetic tendencies toward depression, large sample sizes on a scale required to pinpoint specific factors have proved elusive via classic study recruitment strategy – until now.

Findings a “great leap forward”

Dr Elisabeth Binder, Associate Professor in Psychiatry, Max-Planck Institute of Psychiatry, and member of the European College of Neuropsychopharmacology (ECNP) Executive Committee, says: “This study has proven that sample size is key, as it now identifies over 15 genetic loci with well over 100,000 patients and 300,000 controls. It is also the first study to show that this can be achieved repurposing large commercial databases for science, in this case from 23andme. Without this collaboration such samples sizes could not have been achieved.

“This is a great leap forward for depression researchers and a first glimpse of light on the horizon for clinicians and patients, that in the future, we may be able base diagnoses and treatment on biology.”

Nature versus nurture?

Many experts believe that environmental factors play as much of a role in the development of depression as inherited genetics do, therefore the potential for future treatments to eliminate the risk of depression may not be as straightforward as, for example, gene therapy to control one or two genes.

For more on some of the symptoms of depression, view our Live Healthy article on Men and Depression.


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Georgie Fenn, writes most of our news articles and social media posts.