Some Are More Resilient To Seasonal Depression Because Of Special Ability, Denmark Study Says

Per Medical News Today, the National Institute of Mental Health estimates that 6.7 percent of the American population had an experience with depression over the past year. Beyond that, five percent of the population suffers from Seasonal Affective Disorder (SAD). The specific cause of SAD has not yet been concluded, but scientists believe that there is a certain gene which makes people more likely to develop depression in the wintertime.

However, just because someone has this gene doesn’t mean they will necessarily experience SAD. Scientists from Copenhagen, Denmark sought to find out why some people are more resilient to SAD despite their genetics, Medical News Today reports. The team, led by Dr. Brenda McMahon, published their findings in the journal European Neuropsychopharmacology this August. What scientists already knew about SAD was that in the wintertime, when people are exposed to less sunlight, their bodies make less serotonin, which leads to feelings of depression. Dr. McMahon explained the concept in a simple statement.

“Daylight is effectively a natural antidepressant. Like many drugs currently used against depression, more daylight prevents serotonin [from] being removed from the brain,” Dr. McMahon said, according to Medical News Today.

Apparently, a study had previously found that those who experience SAD are more likely to carry a gene which plays a role in regulating the removal of the happy hormone serotonin. The transporter proteins that control how much serotonin is removed from the brain are not being lowered enough in the wintertime when serotonin is more scarce. Therefore, these people don’t keep enough serotonin in the winter and wind up depressed.

But the new Denmark study has now found that some people’s bodies are able to control their level of serotonin reuptake proteins, decreasing the amount in the winter so that more serotonin is allowed to remain in the brain. When summer comes again and more sunlight is available, these people’s bodies apparently increase the level of serotonin reuptake proteins again so that serotonin levels are again appropriate. Dr. McMahon summarized the findings.

“We found that some people who you would expect to have SAD because of their genetic disposition were nevertheless able to control how much serotonin transporter was produced, which means that they were able to regulate how much serotonin was removed from their brain.”

This newly discovered mechanism works similarly to how Selective Serotonin Reuptake Inhibitor (SSRI) drugs work. Scientists should now be able to use this new information in order to come up with better treatment solutions for Seasonal Affective Disorder. Dr. McMahon’s summary recommended the use of SSRIs in treating SAD.

“Our findings offer good grounds for treatment of SAD with [selective serotonin reuptake inhibitors],” said Dr. McMahon.