Depression is characterized by severe emotional despondency and dejection felt over a period of time and accompanied by feelings of hopelessness and inadequacy. Common symptoms include difficulty with remembering things or making decisions, setting priorities, planning, and taking action. Free radical oxidative stress is one of the main causes of the mechanisms that contribute to depression. Glutathione is a new way to treat the condition. The results of a clinical trial published in a 2008 issue of “Biological Psychiatry” showed that taking 1 gram of N-acetyl cysteine as a supplement twice daily for 24 weeks increases glutathione levels in the body and helped alleviate depressive symptoms.

http://www.ncbi.nlm.nih.gov/pubmed/18534556