Cautionary notes
Commenting on the study for Medscape Medical News, Kuan-Pin Su, MD, PhD, chief of the Department of General Psychiatry, China Medical University, Taichung, Taiwan, highlighted some of the limitations cited by the investigators.
First, depression or depressive symptoms were defined using self-rating scales, which are “convenient to screen for depressive disorders, but a high score obtained on a self-rating scale does not necessarily indicate the presence of depressive psychopathology,” said Su, who was not involved with the research.
He also noted that use of 465 mg of EPA and 375 mg of DHA in VITAL-DEP “might be too low” to have an impact.
Finally, Su said it is “very important to also address the potential for type I error, which makes the secondary and subgroup analyses less reliable.”
VITAL-DEP was supported by a grant from the National Institute of Mental Health. Pronova BioPharma donated the fish oil and matching placebo. Okereke reported receiving royalties from Springer Publishing. Su is a founding committee member of the International Society for Nutritional Psychiatry Research, the board director of the International Society for the Study of Fatty Acids, and an associate editor of the journal Brain, Behavior, and Immunity.
A version of this article first appeared on Medscape.com.