Factors influencing outcomes of depression in clinical practice, especially health-related quality of life (HRQoL), are poorly understood. The Factors Influencing Depression Endpoints Research (FINDER) study is a European prospective, observational study designed to estimate the HRQoL of adults with a clinically diagnosed depressive episode at baseline, and 3 and 6 months after commencing antidepressant medication. We report here the study design and baseline patient characteristics. HRQoL was assessed by the 36-item Short-Form Health Survey (SF-36) and European Quality of Life-5 Dimensions (EQ-5D). Patient ratings on Hospital Anxiety and Depression Scale (HADS) and pain Visual Analogue Scale (VAS) were also obtained. Results (n=3468) showed that SF-36 mental component summary (mean 22.2) was more than two SDs below general population norms (mean 50.0) and one SD below clinical depression norms (mean 34.8); the physical component summary (mean 46.1) was similar to general population (mean 50.0) and clinical depression norms (mean 45.0). Mean EQ-5D scores were also lower than general population norms. Mean HADS-Depression and -Anxiety subscores were 12.3 and 13.0, respectively. Fifty-six percent of patients reported an overall pain VAS score of at least 30mm and 70% of these patients had no physical explanation for their pain. Further investigation into factors associated with HRQoL in depression after treatment initiation is warranted.