Editor’s Note: Anti-Inflammatory Actions of Antidepressants

Norman Sussman, MD, DFAPA

Editor, Primary Psychiatry and Psychiatry Weekly, Professor of Psychiatry, New York University School of Medicine

Some studies suggest that C-reactive protein (CRP), a sensitive marker of inflammation and tissue damage, is elevated in depression. This has led to the hypothesis that increased rate of cardiovascular disease among those with major depressive disorder (MDD) is associated with activation of the inflammatory response.

In 2004, researchers at the Johns Hopkins University School of Medicine reported that a history of MDD is indeed associated with elevated CRP levels, especially among men.

In the most recent issue of The British Journal of Psychiatry researchers from Cork, Ireland, who previously noted that CRP levels are elevated in depressive illness, now present the results of a study that shows that treatment with selective serotonin reuptake inhibitor antidepressants causes a significant drop in CRP levels. This observed reduction is not, however, correlated with improvements in clinical state. That is, there was a significant reduction in CRP concentrations among subjects independently of antidepressant action. These findings indicate that the anti-inflammatory effects of SSRIs could be used in the treatment of inflammatory disorders.

Increasingly depression is being linked to stress-like adverse effects on the brain and cardiovascular system. For example, reduction in hippocampal volume is correlated with the severity and duration of depression. Decreases in brain-derived neurotrophic factor (BDNF) have consistently been shown to parallel this degenerative process. Effective use of antidepressant drugs, regardless of their presumed mechanism of action, can reverse this damage, inducing the sprouting of new neurons. It is possible that CRP levels may be a marker of a similar process in the cardiovascular system. Although the new findings do not answer the question of whether antidepressants decrease morbidity and mortality, the results of the Irish study do support the findings of other trials that antidepressant use is associated with a lower risk of death or recurrent non-fatal heart attack, and lower risk of death from all causes.

Disclosure: Dr. Sussman reports no affiliations with or financial interests in any organization that may pose a conflict of interest.