The genes behind depressive illness

“There is certainly no single gene for depression,” says Professor Cathryn Lewis of King’s College London, a senior author of a study that identified dozens of gene variants that make people more likely to suffer from depression.

Years ago studies of twins showed that depression is partly heritable but the actual genes involved have proved elusive.

For the new study an international team compared the DNA of 135,000 people with a history of depression and 345,000 without. They found 44 gene variants that were more common in those with depression, 30 of which had not previously been linked to the condition.

When subjects were ranked according to their genetic risk factors, those in the top 10% were found to be two-and-a-half times more likely to experience depression than those in the bottom 10%.

Knowing which genes can influence depression should lead to a better understanding of what causes the condition.

It could perhaps lead to new drug treatments, which are much needed given the increasing number of people who suffer from the condition.