Could Eating Fish Make Antidepressants More Effective?

A new study finds that increasing fatty fish intake could be a way to improve the response rate of depressed patients who do not respond to antidepressants.

A team led by researchers from the University of Amsterdam investigated factors influencing antidepressant non-response, and found a connection between fish intake and greater response to antidepressants, measuring the fatty acid and cortisol levels of 70 patients with depression. The authors compared these levels with readings taken from 51 healthy controls. The patients with depression were then administered a 20 mg dose of an selective serotonin reuptake inhibitor (SSRI) every day for 6 weeks.
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Those that did not respond to the SSRIs were provided with a gradually increased dose of up to 50 mg per day. In measuring fatty acid and cortisol levels throughout the trial, the investigators found the depressed patients who did not respond to the antidepressants tended to have abnormal fatty acid metabolism.

The findings “suggest that alterations in fat metabolism and stress hormone regulation determine which depressed patients respond to the antidepressant paroxetine. Interestingly, these alterations were related to eating fatty fish,” says Roel Mocking, MSc, a professor in the department of psychiatry at the University of Amsterdam, and lead author of the study.

This finding may be a result of fatty fish being “a unique cocktail of nutrients,” says Mocking, “including antioxidants, amino acids and omega-3 fatty acids.”

These omega-3 fatty acids, which Mocking and his colleagues measured in blood, “are an important constituent of the brain,” he says. “In the brain, it influences functioning of neurons, and could explain an altered response to paroxetine.”

Given that the study observed an improved response to antidepressants among depressed patients that ate more fatty fish, along with the known beneficial effects of fatty fish on the cardiovascular system, the findings stress “the dietary recommendation of 2 servings of fish a week, including 1 [serving of] fatty fish, in depressed patients taking antidepressants.”

Whether dietary fatty fish can be replaced by artificial omega-3 supplements, however, remains subject to debate, says Mocking, “given the lack of other co-acting nutrients found in fatty fish and the potential of in- or ex-vivo oxidation.”

—Mark McGraw

Reference

Mocking R, Verburg H, et al. P.2.b.031 Longitudinal interplay between paroxetine response, cortisol and fatty acid metabolism in major depressive disorder. European Neuropsychopharmacology. 2014.