What is the role of genetic vulnerability, environmental stressors, and brain structural abnormalities in the development of major depressive disorder (clinical depression)?

Updated: Mar 28, 2019
  • Author: Jerry L Halverson, MD; Chief Editor: David Bienenfeld, MD  more...
  • Print
Answer

Researchers are currently investigating the relationship between genetic vulnerability, environmental stressors, and brain structural abnormalities in the development of depression. In an MRI genetic study, Frodl et al found that patients with major depression who carried the S allele of 5-HTTLPR and had a history of childhood emotional neglect had smaller hippocampal volumes than patients who had only one of those factors. They concluded that structural hippocampal brain changes resulting from stress may be part of the risk for developing depression and that these changes are more pronounced in individuals with the S-allele. [39]

Conflicting evidence exists regarding the interaction between the functional serotonin transporter promoter (5-HTTLPR) and stress in the development of depression. A 2011 meta-analysis suggested that 5-HTTLPR moderates the relationship between stress and depression. [40] Earlier, smaller meta-analyses had concluded that the evidence did not support the presence of the interaction.


Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!