Evidence of efficacy of new drugs is based on clinical studies which include highly selected patient samples. The aim of the present observational study was to verify the findings of clinical escitalopram studies in depression and anxiety with a large and heterogenous patient sample. By means of a simple questionnaire, 626 general practitioners and psychiatrists in private practices from Switzerland documented the course of illness over about 6 weeks in patients for whom a treatment with escitalopram was intended. The questionnaire included information on demographics, severity of illness and related disabilities in daily life, treatment efficacy and tolerability, as well as a rating on the subjectively most disturbing symptom, time to onset of effect and remission. The sample included 5649 patients of whom 2/3 were female. 4282 patients were diagnosed as suffering from depression, 539 from anxiety, and 708 from both depression and anxiety (no information available for 120 patients). "Depressive mood" was rated the most disturbing symptom among the depressive and comorbid patients and "inner tension" was the most disturbing symptom among the anxiety patients. The comorbid patient sample was most often rated as being severely ill (34% vs. 18% [anxiety patients] and 19% [depression patients]), had most often received a previous pharmacological treatment (43% vs. 26% and 31%, respectively) and was most often treated with the higher dose of 20 mg/d escitalopram (34% vs. 22% and 19%, respectively). Treatment outcome was equal between the diagnostic groups and reached values of over 80% for the ratings "good" or "very good". Remission was achieved in 52% of the patients. The average time until patients reported onset of effect was 14 days, and time until remission was stated as early as 24 days. Interestingly, patients achieving remission reported a better tolerability than patients who did not achieve remission. The analysis of adverse events revealed the same profile, albeit with lower frequencies, for side effects as is reported in the product information. No as of yet unknown adverse events were reported. The present evaluation confirmed the clinical profile of escitalopram as it is reported from clinical studies. It became evident that observational studies of this scale may also generate interesting general information such as subjective feelings of patients, the time course of the illness during treatment, and the time at which a change of therapy should be considered in the event of an unsatisfactory response.