A bold question is no longer dismissed: could reducing inflammation alleviate depression? New findings suggest yes.
Traditionally, depression has been viewed mainly as a problem of brain chemistry. But emerging evidence points to a potentially influential role for the immune system, hinting that inflammation may drive or amplify depressive symptoms in some individuals.
A recent systematic review and meta-analysis found that anti-inflammatory treatments can lessen depressive symptoms and, notably, reduce anhedonia—the difficulty or inability to experience pleasure—in people who have both depression and elevated inflammatory markers.
“This is a significant result that could elevate immunopsychiatry into a more practically relevant field,” notes Annelise Madison, the study’s co-first author and an assistant professor of clinical psychology at the University of Michigan, who is also affiliated with the Eisenberg Family Depression Center. Immunopsychiatry examines the links between the immune system and mental health.
The research, funded by federal agencies and other institutions, appears in the American Journal of Psychiatry. Its implications may include more personalized treatment options and potential help for patients who haven’t benefited from conventional antidepressants.
The review encompassed 19 clinical trials involving individuals with depression and signs of inflammation who received various anti-inflammatory medications or placebos for up to 12 weeks. Across these studies, anti-inflammatory strategies alleviated both overall depressive symptoms and anhedonia in participants with high inflammation, without a rise in serious adverse events.
Regarding future drug development, Madison points out that, at present, anti-inflammatory agents are used off-label for depression because the FDA has not approved them for this purpose.
In sum, the meta-analysis may clarify why earlier studies yielded mixed results: if researchers don’t select participants based on their inflammatory status, a heterogeneous group may obscure potential benefits. As she puts it, recruitment focused on an inflammatory phenotype could reveal clearer effects.
The work also involved collaborators from Harvard University and Emory University. Funding came from the National Institute of Mental Health, the L.I.F.E. Foundation Research Grant, Harvard’s Mind Brain Behavior Interfaculty Initiative, and the Massachusetts General Hospital Translational Clinical Research Center’s Early Career Investigator Award.
Source: University of Michigan
