A world of only happy people sounds like a scene from the paranormal cable show “Charmed”. Yet researchers have developed a new breed of permanently ‘cheerful’ mice with the hope that the knowledge gained by exploring the genetic link to depression can be used to develop a new clinical treatment.

Mice breed without the TREK-1 gene, the gene responsible for the transfer of serotonin in the brain, were tested with a variety of measures used to assess ‘depression’ in mice. Surprisingly, they acted as though they had been on antidepressants for at least three weeks.

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

Serotonin is known to play an important role in mood, sleep and sexuality. By breeding mice with an absence of TREK-1, researchers were able create a depression-resistant strain. The details of this research, which involved an international collaboration with scientists from the University of Nice, France, are published in Nature Neuroscience this week.

Mice without the TREK-1 gene (‘knock-out’ mice) were created and bred in collaboration with Dr. Michel Lazdunski, co-author of the research, in his laboratory at the University of Nice, France. “These ‘knock-out’ mice were then tested using separate behavioral, electrophysiological and biochemical measures known to gauge ‘depression’ in animals,” says Dr. Debonnel. “The results really surprised us; our ‘knock-out’ mice acted as if they had been treated with antidepressants for at least three weeks.”

This research represents the first time depression has been eliminated through genetic alteration of an organism. “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.

According to Health Canada and Statistics Canada, approximately 8% of Canadians will suffer from depression at some point in their lifetime. Around 5% of Canadians seek medical advice for depression each year; a figure that has almost doubled in the past decade. Figures in the U.S. are comparable, with approximately 18.8 million American adults (about 9.5% of the population) suffering depression during their life.

Source: McGill University