A review of the use of N-acetylcysteine (NAC) in neuropsychiatry suggests that NAC positively affects such diverse disorders as drug addiction, autism, schizophrenia, depression, and bipolar disorder. The authors caution that much of the research is preliminary and requires further study, but that NAC is well tolerated and a potentially novel therapeutic option for people suffering from psychiatric disorders.

Trends Pharmacol Sci. 2013 Mar;34(3):167-77 (PMID: 23369637)