• BDNF; ECT; Plasma; Treatment-resistant depression;

There is an increasing evidence that the Brain-Derived Neurotrophic Factor (BDNF) could be
involved in the mode of action of antidepressants and, perhaps, of ECT. This study aimed to
investigate whether the clinical course of medication-resistant depressed patients following a course of ECT might be associated with changes of plasma BDNF concentrations. Our findings
showed that at T0 (baseline) plasma BDNF levels of patients were significantly lower than those
of control subjects, and that at T2 (after ECT) were significantly increased in parallel with the
decrease of the Hamilton Rating Scale for Depression (HRSD) total score. However, only remitter patients who showed higher baseline BDNF levels than non-remitters reached normalized BDNF
levels after ECT. These findings would suggest the potential usefulness of baseline plasma BDNF
levels as predictors of response to ECT in treatment-resistant depressed patients.