Objective Evaluation of Depression Using Sleep EEG

Inclusion Criteria: Individuals with Untreated Depression: \- 16 men and 16 women aged from 30 to 59 years, with an approximate ethnic balance of 10 Asian, 3 White and 3 other ethnicity for each gender, whom are diagnosed with Major Depressive Disorder by a psychiatric specialist of this research according to MINI screening and DSM-5 criteria, and defined as a score of 15 or higher on the clinician-administered Hamilton Rating Scale for Depression, Beck Depression Inventory, and Patient Health Questionnaire for Depression (PHQ-9). Healthy Participants: \- 16 men and 16 women age-, ethnic-, and gender-matched healthy participants to the cohort with untreated depression, with absence of mental disorders, including but not limited to depression and sleep disorders, by a psychiatric specialist according to MINI screening and DSM-5 criteria, and negative Hamilton Rating Scale for Depression, Beck Depression Inventory, and Patient Health Questionnaire for Depression (PHQ-9). Exclusion Criteria: Participants corresponding to any of the following conditions are considered ineligible for the trial. * Diagnosed with epilepsy or other organic brain disorder. * Medical conditions resulting in depressive symptoms such as hypothyroidism, Cushing's disease, systemic lupus erythematosus; neurological conditions resulting in depressive symptoms such as Parkinson's disease, Huntington's disease, multiple sclerosis * Patients with suspected sleep apnea, based on symptoms and a BMI of 30 or greater * Prescribed interferon regularly with stimulants, opioid drugs (Ritalin, Opioid, etc.) and steroids * Repetitive thoughts of death, current thoughts about suicide, suicide attempts, or a suicide plan * Tested positive to controlled substance use by a urine drug screening before commencement of testing * Current or past drug or alcohol dependence * Shift work or rotating work schedule * Nursing, pregnant or planning to become pregnant * Participating in other clinical trials