Researchers have uncovered a gene that influences how deeply life experiences will effect a person, and the discovery challenges traditional thinking about genes as risk factors for depression. The gene makes some people more susceptible to depressive disorders after traumatic life events, and the same gene can help some people thrive in positive situations.

The study, published in British Journal of Psychiatry Open, evaluated adults who had experienced sexual or physical abuse as children. The authors aimed to uncover why some of these adults developed depression after the traumatic events and others did not; they focused their research on the SERT gene, which controls the transport of the mood-regulating chemical serotonin. All people have one of three types of the gene: long-long, short-long, or short-short. A total of 333 middle-aged men and women from urban and rural areas were included in the study and the researchers tracked the participants’ depressive symptoms over a 5-year period using the Primary Care Evaluation of Mental Disorder Patient Health Questionnaire.

Participants with the short-short type of the SERT gene who had experienced abuse were more likely to experience ongoing depressive symptoms than participants with other variations of the gene. However, participants with the short-short gene and no history of abuse were more likely to be happier than participants with other genotypes.

Serotonin and the SERT gene have long been associated with mood and depressive symptoms, as well as the efficacy of antidepressant drugs. The SERT gene has also been associated with personality traits and temperament. And, the short-short version of the gene has been associated with a weaker response to stress and less effective coping strategies.

The current study is different from previous examinations of the SERT gene because it used a broader population and studied the participants over a long period of time. The researchers are continuing their research by examining several genes at once to predict vulnerability to stressful life events.

Depression is associated with changes in mood and behavior, as well as changes at the cellular and molecular levels. Symptoms vary widely and affect everyone differently.

Genes are only one piece of a complex puzzle of mental health; genes alone cannot determine psychiatric fate or response to life stress – negative or positive. However, scientists and health care providers may now be able to use a person’s genes to identify if he or she is more likely to develop symptoms of depression and if they will respond to treatment.

As the authors of the study claimed, people cannot change their genes or avoid life stress. But, people can modify their environment and put themselves into healthy environments to allow themselves the best opportunities to thrive and be happy.

References

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), severe childhood abuse and depressive symptom trajectories in adulthood
British Journal of Psychiatry Open, 1 (1), 104-109 DOI: 10.1192/bjpo.bp.115.000380

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