Prospective Assessment of Cost-effectiveness and Side-effects of Depressive Patients Treated With ECT or TCA

Inclusion Criteria: * adult patients (\>18 years) with a major depressive disorder who will either start with ECT or medication * failed response to at least 1 adequate dose-duration trial with antidepressants * moderate or severe depression (HDRS-17 \>16) Exclusion Criteria: * lifetime diagnosis schizophrenia or schizoaffective disorder, current substance abuse disorder, organic brain syndrome * the presence of a concurrent significant medical condition impeding the ability to participate