Cardiovascular Effects of Agomelatine and Escitalopram in Patients With Major Depressive Disorder (MDD)

Inclusion Criteria: * Aged 18-65 years. * Capable of understanding and willing to provide signed and dated written, voluntary informed consent in advance of any protocol-specific procedures. * MDD or MDD with melancholia according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria. Patients with comorbid panic or anxiety disorders will be included if MDD is the primary diagnosis. * Hamilton Depression (HAM D) \> 18. * Beck Depression Inventory (BDI-II) \>18. Exclusion Criteria: * Aged \< 18 or \> 65 years. * Current antidepressant treatment. * Previous failed response to SSRI treatment at the maximum tolerated dose for at least 4 weeks. * Known or suspected hypersensitivity to either escitalopram or agomelatine or any of their ingredients. * Current high suicide risk. * Comorbid panic or anxiety disorders as the primary diagnosis. * Pre-existing and/or current diagnosed heart disease. * Comorbid medical conditions including type 1 diabetes, hepatic impairment (cirrhosis or active liver disease), medicated hypertension, epilepsy, bleeding disorders, alcohol/drug dependence, infectious blood diseases, psychotic disorders, personality disorders, eating disorders, mental retardation, dementia (ie, Mini Mental State Examination \[MMSE\] \< 23), or gastrointestinal illness or previous bariatric (weight loss) surgery that may impair antidepressant absorption. * Participants on betablockers (for example, metoprolol). * Participants currently taking the following contraindicated medications for agomelatine and/or escitalopram: * Cytochrome (CYP) P450 1A2 inhibitors (e.g. fluvoxamine, ciprofloxacin) * Monoamine Oxidase Inhibitors; * Irreversible non-selective monoamine oxidase inhibitors (MAOIs) * Reversible, selective MAO-A inhibitor (e.g. moclobemide) * Reversible, non-selective MAOI (e.g. linezolid) * Pimozide Participants who are eligible to take part in the study are prohibited to take the contraindicated medications listed above for the entire duration of the study. * Clinically significant abnormalities on examination or laboratory testing and clinically significant medical conditions not listed above that are serious and/or unstable. * Pregnant or breastfeeding women. * Women of childbearing potential (WOCP) who are not using medically accepted contraception (ie, intrauterine devices \[IUDs\], hormonal contraceptives \[oral, depot, patch or injectable\], and double barrier methods such as condoms or diaphragms with spermicidal gel or foam). Women who are postmenopausal (ie, amenorrhea for at least 12 consecutive months) or surgically sterile are not considered to be WOCP. * Sexually active men with WOCP partners who are not using medically accepted contraception. Medically accepted contraception for women and sexually active men with WOCP partners will be continued throughout the study and for 30 days after the last antidepressant dose.