Are fish oils an effective therapy in mental illness--an analysis of the data.

Objective: To review the literature regarding the use of fish oils in the treatment of psychiatric illness.

Method: A Medline search was conducted in September 1999.

Results: Five papers have investigated omega-3 fatty acids levels in depression. One study used omega-3 fatty acids as an adjunctive therapy in bipolar disorder. Four studies used fatty acids as an adjunctive therapy in schizophrenia.

Conclusion: There is a great deal of current research in this field. While omega-3 fatty acids levels may be lowered in depression, there are no data suggesting that omega-3 fatty acids are effective. One paper indicates that omega-3 fatty acids are effective in bipolar disorders. The data on schizophrenia are conflicting. Omega-3 and omega-6 fatty acids have proved effective. Most of the evidence suggests that the main effect is an improvement in negative symptoms. One recent study showed that omega-3 fatty acids had no effect on negative symptoms.