Influence of depressed patients' expectations prior to electroconvulsive therapy on its effectiveness and tolerability (Exp-ECT): a prospective study.

Electroconvulsive therapy (ECT) is the most effective therapy for severe depressive disorders. Though there are known clinical predictors of response (e.g., higher age, presence of psychotic symptoms), there is a lack of knowledge concerning the impact of patients' expectations on treatment outcome and tolerability in terms of possible placebo/nocebo effects. In 31 patients with unipolar or bipolar depressive disorder, we used a questionnaire to investigate the patients' expectations of ECT effectiveness and tolerability prior to and in the course of the treatment. Additionally, the questionnaire was used after the ECT course for a final assessment. Depressive symptoms and putative side-effects were measured at each time point. General linear models were used to analyze the course of depressive symptoms and patients' expectation of ECT effectiveness and tolerability. ECT significantly reduced depressive symptoms with large effect sizes. Patients' rating of ECT effectiveness decreased in parallel: While responders' rating of ECT effectiveness remained stable on a high level, non-responders' rating decreased significantly. Group difference was significant after, but not prior to and during the treatment. Regarding tolerability, there was a (temporary) significant increase in the severity of self-rated symptoms such as headache and memory impairment. In contrast, patients' expectation and assessment of ECT tolerability remained unchanged, and their expectations prior to ECT had no impact on the occurrence of side-effects. These findings contradict the presence of relevant placebo/nocebo effects in the context of ECT when investigating a population of mostly chronic or treatment resistant patients with moderate to severe depressive disorder.