The study period lasted one year at each of the sites, although the whole study took 17 months due to the varying start times. Eligible participants were aged 18 years or older, had presented with symptoms to an outpatient clinic, and had then screened positive for depression when using the two-question (depressed mood and/or loss of interest) screening questionnaire, had experienced a first episode of MDD or recurrent episodes, and/or recurrent episodes of dysthymia or double depression. Exclusion criteria were: comorbidity, pregnancy, and lactation; severe substance abuse; cognitive impairment on Mini-Mental Status Examination; a history of schizophrenia or bipolar disorder; and failure to provide written informed consent.