Effects of deep brain stimulation on dopamine D2 receptor binding in patients with treatment-refractory depression

Depression is a chronic psychiatric disorder related to diminished dopaminergic neurotransmission. Deep brain stimulation (DBS) has shown effectiveness in treating patients with treatment-refractory depression (TRD). This study aimed to evaluate the effect of DBS on dopamine D2 receptor binding in patients with TRD.

Six patients with TRD were treated with bed nucleus of the stria terminalis (BNST)-nucleus accumbens (NAc) DBS were recruited. Ultra-high sensitivity [¹¹C]raclopride dynamic total-body positron emission tomography (PET) imaging was used to assess the brain D2 receptor binding. Each patient underwent a [¹¹C]raclopride PET scan for 60-min under DBS OFF and DBS ON, respectively. A simplified reference tissue model was used to generate parametric images of binding potential (BP_ND) with the cerebellum as reference tissue.

Depression and anxiety symptoms improved after 3-6 months of DBS treatment. Compared with two-day-nonstimulated conditions, one-day BNST-NAc DBS decreased [¹¹C]raclopride BP_ND in the amygdala (15.9 %, p < 0.01), caudate nucleus (15.4 %, p < 0.0001) and substantia nigra (10.8 %, p < 0.01).

This study was limited to the small sample size and lack of a healthy control group.

Chronic BNST-NAc DBS improved depression and anxiety symptoms, and short-term stimulation decreased D2 receptor binding in the amygdala, caudate nucleus, and substantia nigra. The findings suggest that DBS relieves depression and anxiety symptoms possibly by regulating the dopaminergic system.