Scientists have identified a link between a particular gene and depression, marking a potential breakthrough in ways to treat the condition in future.

In a study of 15,000 people, researchers from Germany’s Max Planck Institute of Psychiatry discovered that slight changes in genetic code influenced a gene called SLC6A15 and that the changes were closely linked with depression.

The SLC6A15 gene, which is believed to regulate the brain’s excitatory transmitter glutamate, was less active in depressed people, the study found.

Dr Martin Kohli, a co-author of the report from the Max Planck Institute, was quoted as saying that the gene could be targeted by specialised drugs.

“Identification of mechanisms causing depression is pertinent for discovery of better treatments,” he said.

Dr Alex Wilde from the University of NSW’s School of Psychiatry said the breakthrough could be significant for her field of science.

“If there are deficits in the way this gene is expressed in depressed people, psychotropic drugs to treat depression could be designed that specifically boost this gene’s activity in the hippocampus,” she told The Conversation.

However, she said that not a lot was known about the interaction between genetics and environmental factors linked to depression (such as a traumatic childhood or the death of a parent).

An under active SLC6A15 gene in depressed people could also be driven by outside factors causing emotional stress, she said.

“So genetic test to detect SLC6A15 activity in healthy people susceptible to depression because of their family history would be less relevant if expression of the gene is only compromised during a depressive episode,” she said.

The study was published in the journal Neuron.