Depression in medical students: gene-environment interactions.

This study investigated the interaction of genetic, environmental, and psychological factors in predicting depression and anxiety symptoms in medical students.

First-year medical students (n=141) completed measures of anxiety, depression, hope, and spiritual meaning at three time points during the first year. Buccal samples were utilized to genotype each individual at the s/l variant in the promoter region of the serotonin transporter gene (5-HTTLPR). A subset (n=91) completed a measure of recent stressors.

Mean levels of depression increased during year one of medical school. Presence of the s/s genotype in the promoter region of the 5-HTT gene was associated with greater increases in depression, but only in association with higher numbers of recent stressors.

Spiritual meaning and hope were found to counteract genetic susceptibility to stress-related depressive symptoms in the more vulnerable s/s group.