London, Jan 11 (IANS): More than 200 genes linked to depression have been newly identified, which may soon lead to treatments for the mental health condition suffered by thousands of people.

The research, published in Nature Genetics, found more than 50 new genetic loci (a locus is a specific position on a chromosome) and 205 novel genes that are associated with depression in the first large-scale global study of the genetics of major depression in participants of diverse ancestry groups.

The study, led by researchers at the University College London, also showcases the potential for drug repurposing, as one of the identified genes encodes a protein targeted by a common diabetes drug, while also pointing to new targets for drugs that may be developed to treat depression.

The international research team reviewed genetic data from 21 study cohorts from several countries and included nearly one million study participants of African, East Asian, South Asian, and Hispanic/Latin American descent, including 88,316 people with major depression.

The study has made major advances in identifying genes that are linked to the risk of depression, both for newly identified links and by strengthening prior evidence, and showcases some genes with potential implications for drug development, such as NDUFAF3.

The protein that NDUFAF3 encodes has been implicated previously in mood instability, and it is targeted by metformin, the first-line drug for treating Type 2 diabetes.

Animal studies of metformin have suggested a possible link with reduced depression and anxiety, so this latest finding further suggests that additional research into metformin and depression may be warranted.

Other genes identified in the study may have biologically plausible links with depression, such as a gene linked to a neurotransmitter involved in goal-directed behaviour and genes encoding a type of protein previously linked with multiple neurological conditions.

Surprisingly, the researchers found less overlap in the genetic hits for depression across ancestry groups than expected, at about 30 per cent, which is less overlap than previously found for other traits and diseases.

Therefore, it is even more important to study depression in diverse samples because some of the findings might be ancestry-specific, they said in the paper.