Lead author Dr. Alexander B. Niculescu, an associate professor of psychiatry Indiana University School of Medicine in Indianapolis, said the mice used in the study have characteristic bipolar symptoms, including being depressed and, when subjected to stress, becoming manic.
The fatty acid DHA, one of the main active ingredients in fish oil, "normalized their behavior," Niculescu said.
"The mice that were given DHA normalized their behavior, they are not depressed and when subjected to stress, they do not become manic," Niculescu said in a statement. "When we looked into their brains, using comprehensive gene expression studies, we were surprised to see that genes that are known targets of psychiatric medications were modulated and normalized by DHA."
An unexpected finding was that mice given DHA also showed a reduced desire for alcohol.
"These bipolar mice, like some bipolar patients, love alcohol. The mice on DHA drank much less; it curtailed their alcohol abusive behavior," Niculescu said. "There is now substantial evidence at the molecular level that omega-3 fatty acids work on the brain in ways similar to psychiatric drugs."
The findings are published in the Journal Translational Psychiatry.