Researchers at the University of Nice, France claim to have created a depression-resistant strain of mice by breeding them with the absence of TREK-1 gene. TREK-1 is a gene that can affect transmission of serotonin, which is known to play an important role in mood, sleep and sexuality.

The permanently 'cheerful' mice are providing hope of a new treatment for clinical depression. This research represents the first time depression has been eliminated through genetic alteration of an organism.

"Depression is a devastating illness, which affects around 10% of people at some point in their life. Current medications for clinical depression are ineffective for a third of patients, which is why the development of alternate treatments is so important," says Dr. Guy Debonnel an MUHC psychiatrist, professor in the Department of Psychiatry at McGill University, and principal author of the new research.

"These 'knock-out' mice were then tested using separate behavioral, electrophysiological and biochemical measures known to gauge 'depression' in animals. The results really surprised us; our 'knock-out' mice acted as if they had been treated with antidepressants for at least three weeks," says Debonnel.

"The discovery of a link between TREK-1 and depression could ultimately lead to the development of a new generation of antidepressant drugs," noted Dr. Debonnel.

The study appears in the journal Nature Neuroscience.