Open-label Long Term (52 Weeks) Safety and Tolerability of Agomelatine Sublingual Tablets in Major Depressive Disorder (MDD)

Inclusion Criteria: Key Inclusion Criteria Cohort I: * Documentation of completion of a Novartis AGO178C Double-blind Study in MDD patients. * Male and female adults, 18 through 71 years of age, inclusive (i.e., same age range as for Double-blind Study, but with upper age limit increased by 1-year to accommodate patients whose age increased during the Double-blind Study). * Female patients should continue to use effective contraception as defined in double-blind study protocol. Inclusion Criteria: Key Inclusion criteria Cohort II: * Male and female adults, 18 through 70 years of age, inclusive. * Diagnosis of MDD, single or recurrent episode, according to DSM-IV criteria. * Current episode ≥4 weeks. * CGI-Severity score ≥4 at Screening and Baseline. Exclusion Criteria: Key Exclusion Criteria Cohort I: * Concomitant use of fluvoxamine. * Any significant medical condition that emerged during Double-blind Phase of a previous study, which may interfere with study participation and/or study assessments as assessed by the investigator. Exclusion Criteria: Key Exclusion criteria Cohort II: * History of bipolar disorder (I or II), schizophrenia, schizoaffective disorder, eating disorder (current or during previous one year), obsessive-compulsive disorder. * Any other current Axis I disorder other than MDD which is the focus of treatment. * Substance or alcohol abuse in the last 30 days, dependence in the last 6 months. * Prior exposure to agomelatine. * Female patients of childbearing potential who are not using effective contraception. Other protocol-defined inclusion/exclusion criteria may apply.