Psychobiology of depressive disorders: Gene-environment interactions and the pathophysiology of major depression

Pedro L. Delgado

Research output: Contribution to journalArticlepeer-review


The risk for major depressive disorder is increased by both genetic factors and living through stressful and/or traumatic life events. New research shows that certain genetic differences in the regulation of the serotonin neurotransmitter system are associated with greater likelihood of developing major depression, but only when people lived through stressful life situations. In the absence of serious life stress, the same genetic differences did not contribute to risk of major depression. The basic neuroscience that may underlie the way in which stress predisposes to depression in the face of functional differences in serotonergic function is beginning to be understood. These findings have profound implications for the field and suggest that certain forms of major depression result from trauma in genetically susceptible people - in essence that some forms of depression may be considered a type of a posttraumatic stress syndrome. This hypothesis suggests that certain forms of major depressive illness may be preventable or that the course of illness may be favourably modified by aggressive early intervention. In this context, some of the most important steps in treatment may involve increasing resilience among vulnerable and at-risk individuals and early aggressive intervention with strategies aimed at improved adaptation and coping in people living with stressful situations and/or chronic or serious general medical illness. Objectives. (1) To learn the relevant aspects of the current literature regarding the role of brain neurotransmitters in depression; (2) to learn the results of studies depleting neurotransmitters in living humans; (3) to identify the important areas of the brain that are likely to be involved in the regulation of emotion relevant to depression and to stress responses; (4) to learn about the new research showing that reducing stress will improve the growth of brain nerve cells.

Original languageEnglish (US)
Number of pages1
JournalInternational Journal of Psychiatry in Clinical Practice
Issue numberSUPPL. 1
StatePublished - May 1 2007

ASJC Scopus subject areas

  • Psychiatry and Mental health


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