Short-term Study of Combination Treatment of Escitalopram and Gaboxadol in Major Depressive Disorder

Randomised, Double-Blind, Parallel-Group, Placebo-Controlled, Fixed-Dose Study of Escitalopram in Combination With Two Fixed Doses of Gaboxadol Compared to Escitalopram in Major Depressive Disorder

To compare the efficacy of escitalopram fixed dose 20 mg/day in combination with fixed doses of gaboxadol (5 and 10 mg/day) versus escitalopram fixed dose 20 mg/day after 8 weeks of treatment in patients with Major Depressive Disorder

Subjects participating in this study will be respectively randomised (1:2:2:2) to receive either:

• placebo or
• escitalopram 20 mg/day or
• escitalopram 20 mg/day in combination with gaboxadol 5 mg/day or
• escitalopram 20 mg/day in combination with gaboxadol 10 mg/day

Inclusion Criteria:

Clinical Diagnosis of MDD according to DSM-IV-TR criteria:

• With reported duration of the current major depressive episode of at least 3 months
• With MADRS total score of at least 30

Exclusion Criteria:

The patient has 1 or more of the following:

• Any current psychiatric disorder other than MDD as defined in the DSM-IV-TR
• Current or past history of: manic or hypomanic episode, schizophrenia, or any other psychotic disorder, including major depression with psychotic features, mental retardation, organic mental disorders, or mental disorders due to a general medical condition as defined in the DSM-IV-TR
• Any substance disorder (except nicotine and caffeine) within the previous 6 months as defined in the DSM-IV-TR
• Presence or history of a clinically significant neurological disorder (including epilepsy)
• Neurodegenerative disorder (Alzheimer disease, Parkinson disease, multiple sclerosis, Huntington disease, etc)
• Any Axis II disorder that might compromise the study
• Previous use of hallucinogenic drug

The patient has a significant risk of suicide according to the investigator's opinion, or has a score >=5 on item 10 (suicidal thoughts) of the MADRS, or has made a suicide attempt in the previous 12 months.