Inclusion Criteria:

• Age 18 years or older.
• Diagnosis of Type-1 or Type-2 diabetes mellitus (excluding gestational diabetes) by a specialist at least 6 months prior to the study.
• Current diagnosis of major depression based on DSM-IV criteria .
• Hamilton Depression Rating Scale (HAMD) baseline score > 17
• Available for 14-weeks of treatment and all evaluations.
• Able to understand study rules and procedures and willing to sign written informed consent for study participation.

Exclusion Criteria:

• Competence: Not competent to understand and sign informed consent forms and/or to understand and answer the evaluations.
• Psychiatric exclusions: One or more of the following: Alcohol or substance abuse or dependence in past 6 months; psychotic symptoms or history of psychosis; bipolar disorder; organic brain syndrome; significant suicide risk; homicidal thoughts.
• Medical exclusions: Known intolerance or hypersensitivity to escitalopram or other SSRI; pregnancy; breastfeeding; women of childbearing potential not using adequate contraception; significant renal or hepatic dysfunction (such that demands medical workup and/or regular follow up); resting heart rate less than 40/minute (or 50/minute if symptomatic); uncontrolled hypertension (systolic blood pressure >180 mm Hg or diastolic blood pressure >100 mm Hg); any acute or unstable medical condition that might interfere with the safe conduct of the study.
• Concomitant medication(s) exclusion: Current use (within 2 weeks of enrollment) of one or more of the following: antidepressants; regular benzodiazepine; neuroleptics; anticonvulsants; reserpine; guanethidine; clonidine; methyldopa.