NMDA Modulation in Major Depressive Disorder

Most of the current antidepressants for major depressive disorder (MDD) are based upon the monoamine hypothesis which cannot fully explain the etiology of depression. NMDA hypofunction has been implicated in the pathophysiology of depression. Therefore, this study will examine the efficacy and safety as well as cognitive function improvement of an NMDA enhancer (NMDAE) in the treatment of MDD in the adults.

Inclusion Criteria: * Have a DSM-5 (American Psychiatric Association) diagnosis of MDD * 17-item Hamilton Rating Scale for Depression total score ≥ 18 * Free of antidepressant drugs for at least 2 weeks * Agree to participate in the study and provide informed consent Exclusion Criteria: * Current substance abuse or history of substance dependence in the past 6 months * History of epilepsy, head trauma, stroke or other serious medical or neurological illness which may interfere with the study * Bipolar depression, schizophrenia or other psychotic disorder * Moderate-severe suicidal risks * Severe cognitive impairment * Initiating or stopping formal psychotherapy within six weeks prior to enrollment * A history of severe adverse reaction to SSRIs * A treatment-resistant history (that is, they have failed to respond to two or more different classes of antidepressants with adequate dosage and treatment duration * A history of previously received electroconvulsive therapy * Inability to follow protocol