Methods: 240 patients with acute coronary syndromes (ST-elevation myocardial infarction [STEMI]), non-STEMI or unstable angina) will be enrolled within 8 weeks after ACS and will be randomly assigned to treatment with escitalopram/placebo (5-20 mg) in 52 weeks. Primary outcome measures are the diagnosis of depression and HDS (Hamilton Depression Scale). Psychiatric measurements: SCAN (Schedules for Clinical Assessment in Neuropsychiatry), HDS, HAS (Hamilton Anxiety Rating Scale), Udvalg for Kliniske Undersogelser (UKU) Side Effect Rating Scale, ESSI (Enhancing Recovery in Coronary Heart Disease [ENRICHD] Social Support Instrument), SF-36 (Short Form-36 Health Survey), SCL-92 (Symptom Check List) and BDI (Beck´s Depression Inventory). Cardiological measurements are blood pressure, electrocardiography, echocardiography (left ventricular ejection fraction), heart rate variability and use of medicine.