A [ 11 C]raclopride positron emission tomography study of dopamine‐D 2/3 receptor binding in patients with severe major depressive episodes before and after electroconvulsive therapy and compared to control subjects

AIM: The aim of the study was to test: (i) if D2 /D3 binding in three functional subsections of striatum is different in patients with severe major depressive episodes than in controls; and (ii) if this difference is normalized after electroconvulsive therapy (ECT). METHODS: Nine inpatients were examined with positron emission tomography (PET) and the radioligand [(11) C]raclopride before and after an average of 8.4 ECT sessions. Treatment response was assessed using the Montgomery-Asberg Depression Rating Scale. Nine age- and sex-matched controls were examined twice with PET and [(11) C]raclopride. RESULTS: [(11) C]raclopride binding was significantly lower in all three subsections of striatum in patients compared to controls (Cohen's dz , 1.14-1.68; P = 0.003-0.027). Montgomery-Asberg Depression Ratings decreased significantly after ECT (P < 0.001; Cohen's dz , 2.9). ECT had no statistically significant effect on [(11) C]raclopride binding, although post-ECT binding estimates were more similar to those obtained in controls in all subsections of striatum. CONCLUSION: Using PET and [(11) C]raclopride, we found support for the notion that severe major depressive episodes are associated with significantly lower dopamine D2 /D3 binding in all three subsections of striatum compared to controls. We noted no significant effect on D2 /D3 binding in the patient group after response to ECT.