Acupuncture treatment modulates the corticostriatal reward circuitry in major depressive disorder

Major depressive disorder (MDD) is a common disorder with a high prevalence and significant social and economic impacts. Nevertheless, the treatment of MDD is far from satisfactory. Acupuncture treatment has emerged as a promising method for treating MDD. However, the neural mechanism by which acupuncture reduces depressive symptoms is not fully understood. Studies have shown that the corticostriatal reward circuitry is associated with the pathophysiology of MDD; thus, we investigated the corticostriatal resting-state functional connectivity (rsFC) before and after real and sham acupuncture treatments combined with the antidepressant fluoxetine. Forty-six female major depressive patients were assigned to either verum acupuncture plus fluoxetine (n = 22) or sham acupuncture plus fluoxetine (n = 24) treatment for 8 weeks, and resting state functional magnetic resonance imaging (fMRI) data were collected before the first and after the last treatment sessions. The results showed that compared with sham acupuncture, the verum acupuncture group showed: (1) significantly increased rsFC between inferior ventral striatum and medial prefrontal cortex, ventral rostral putamen and amygdala/parahippocampus, as well as dorsal caudate and middle temporal gyrus; (2) significantly decreased rsFC between right ventral rostral putamen and right dorsolateral prefrontal cortex, and right dorsal caudate and bilateral cerebellar tonsil. The increased rsFC between the inferior ventral striatum and medial prefrontal cortex, ventral rostral putamen and amygdala/parahippocampus were significantly positively associated with decreased clinical scores (Montgomery-Åsberg Depression Rating Scale and Self-Rating Depression Scale scores) at the end of the eight-week treatment. Our findings suggest that acupuncture may achieve treatment effects by modulating the corticostriatal reward/motivation circuitry in MDD patients.