The Effect of Fish Oil in Major Depressive Disorder

Inclusion Criteria: 1. DSM-IV criteria for major depressive disorder. 2. Age being age 18-65. 3. Capacity and willingness to give written informed consent. Exclusion Criteria: 1. Any major medical illnesses. 2. A recent or past history of any Axis-I diagnoses besides major depressive disorder, including psychotic disorders; cognitively impaired mental disorders; impulse control disorders; substance use disorder or substance abuse (last 6 months prior to the studies); primary anxiety disorders, including post-traumatic stress disorder and panic disorder; and bipolar disorders; or Axis-II diagnoses, i.e. borderline and antisocial personality disorder.