Women are more prone to depression than men, a phenomenon potentially linked to reduced pleasure caused by systemic inflammation. A new U.S. study suggests inflammation may exacerbate this pleasure deficit in women without similarly affecting men.
Conducted by researchers at the University of California, Los Angeles, the study was published in the journal Biological Psychiatry: Cognitive Neuroscience and Neuroimaging. Participants, both men and women, first underwent a procedure to induce and increase inflammation in their bodies. They then played a game offering monetary rewards while researchers monitored activity in their brain's reward centers.Results revealed that women with heightened inflammatory responses exhibited reduced activity in their reward centers when potential rewards were presented—a phenomenon absent in men. In other words, inflammation dampens the female brain's reward response without affecting males. Diminished reward center activity signals anhedonia, a core symptom of depression characterized by loss of interest in external stimuli and persistent low mood.
Study author Dr. Naomi Eisenberger of UCLA notes that women are known to be diagnosed with depression two to three times more often than men. This new finding suggests that inflammation-induced gender differences in pleasure perception may be a key factor in the imbalance of depression risk between the sexes.Additionally, women with chronic inflammatory conditions may be more susceptible to depression due to reduced sensitivity to rewards. Clinicians treating inflammatory diseases in women should be particularly vigilant for potential depressive symptoms in these patients.