Influence of age on ECT efficacy in depression and the mediating role of psychomotor retardation and psychotic features

To investigate whether older age predicts a higher efficacy of electroconvulsive therapy (ECT) in severely depressed patients. Also, to analyze whether psychomotor disturbance and/or psychotic features might explain the potential higher efficacy of ECT in older age.A total of 96 patients with major depressive disorder treated with bilateral ECT were evaluated. The 17-item HAM-D and the MADRS were used to evaluate the efficacy of ECT and time to remission, respectively. Psychomotor disturbance was defined according the HAM-D.Middle-aged (MA; 50-70 years) and older-aged (OA; ≥70 years) patients had a non-significant larger symptom reduction compared with young-aged (YA;50 years) patients. Medium effect size was found in favor of MA (d = 0.44) and small effect size in favor of OA (d = 0.30), when compared to YA. Patients with psychotic features and patients with psychomotor retardation had a significantly larger symptom reduction (p 0.001 and p = 0.005, respectively; d = 0.88 and d = 0.66, respectively). The association between age and ECT efficacy is mediated by psychomotor retardation (p = 0.049) and in lesser extent by psychotic features (p = 0.071).The results show that psychomotor retardation and psychotic features are strong predictors of ECT efficacy and explain the association between age and ECT efficacy. Instead of focusing on the age of a patient, clinicians should focus on the presence of psychomotor disturbances and psychotic features of depression, when considering ECT treatment.