An examination of anhedonia as a predictor of response with transcranial magnetic stimulation treatment for youth with depression

This exploratory study examined the relationship between the change in anhedonia symptoms and treatment response in adolescents receiving 1 Hz or 10 Hz transcranial magnetic stimulation (TMS) treatment for major depressive disorder (MDD). Participants were aged 12–18 years, had a depressive symptom score of 40 or higher on the Children’s Depressed Rating Scale-Revised (CDRS-R), and were randomized to either the 1 Hz (n = 22) or 10 Hz (n = 19) group for 30 daily TMS treatments over the left dorsolateral prefrontal cortex (LDLPFC). Anhedonia was measured using items from the Beck Depression Inventory-II and CDRS-R. Treatment outcome was assessed with the Clinical Global Impressions-Improvement scales (CGI-I). Logistic regression was used to estimate the odds of CGI-I treatment response from the change in anhedonia symptoms (baseline to week 6), and a linear mixed model of repeated measures analyzed the change in anhedonia (baseline, weeks 4 and 6) compared between the TMS treatment groups over the 6-week study period. TMS stimulus frequency did not affect the change in anhedonia and CGI-I response. There was a significant inverse relationship concerning the change in anhedonia symptoms and CGI-I response for both the 10 Hz (p = 0.0109, δ= −0.8581, SE= 0.3371) and 1 Hz (p = 0.0277, δ= −1.1017, SE=0.5003) groups. Thus, as anhedonia symptoms improved over the 6 weeks, the probability of CGI-I response at week 6 increased for both the 1 Hz and 10 Hz TMS groups. An adjusted least squares for anhedonia revealed a significant improvement in anhedonia for TMS groups (10 Hz, p < 0.0001, d=0.9032; 1 Hz, p < 0.0001, d=0.8536). Future studies of anhedonia may inform precision TMS treatments for youth.