Bipolar disorder, also known as manic-depressive illness, is a brain disorder that causes unusual shifts in energy, mood and behavior. Different from the normal ups and downs everyone experiences, bipolar disorder symptoms are severe and usually emerge in late adolescence or early adulthood. Researchers in this study explained that lingering depression is common in bipolar disorder and that current drug treatments do not work well. Study authors also noted that those with bipolar disorder often lack the antioxidant glutathione, which protects cells from toxins.
Researchers gave 75 participants with bipolar disorder 1 gram of N-acetyl cysteine (NAC) per day along with their usual medications. Scientists believed NAC helps the body produce glutathione in the brain and hoped the nutrient might help reduce depressive symptoms. After eight weeks, depressive symptoms in the NAC group began to improve significantly and continued to improve through 20 weeks. Participants then stopped taking NAC for the next four weeks, during which time symptoms reemerged.