Genes and Behaviour

[andrewducker]

The Anxiety of Depression

Individuals with the "long" version of the gene, which regulates serotonin, could cope with challenges such as the death of family a member, a major breakup or getting fired. People with the "short" version of the gene were much more likely to fall into depression following a major life crisis.

Only 17 percent of those with the long variation of the gene who suffered multiple stressful events developed depression. Forty-three percent of those with the other version of the gene became depressed.

She added that other research offers evidence that the 5-HTT gene is the active gene. "It is known to be expressed in the brain and it has been shown to be associated with reactions to stressful stimuli in mice, monkeys and people undergoing brain imaging," Moffit said.

Eight prior studies found no direct connection between the 5-HTT gene and depression.

Moffitt said she and her colleagues found the connection between 5-HTT and depression only because they took individuals' stress histories into consideration in addition to their depression status. She suggested researchers use the study as a model for studying the nature-vs.-nurture question vis-à-vis other mental disorders.

"In my opinion," Carlezon said, "the most important aspect of this work is that it makes a connection between specific genes in the brain and complex behaviors in people."