Flawed study
In a comment, Natalie Rasgon, MD, founder and director of the Stanford (Calif.) Center for Neuroscience in Women’s Health, said the study was “well researched” and “well written” but had “methodological issues.”
She questioned the sibling component, “which the researchers regard as confirming causality.” The effect may be “important but not causative.” Causality in people who are recalling retrospectively “is highly questionable by any adept researcher because it’s subject to memory. Different siblings may have different recall.”
The authors also didn’t study the indication for OC use. Several medical conditions are treated with OCs, including premenstrual dysphoric disorder, the “number one mood disorder among women of reproductive age.” Including this “could have made a huge difference in outcome data,” said Dr. Rasgon, who was not involved with the study.
Anne-Marie Amies Oelschlager, MD, professor of obstetrics and gynecology, University of Washington, Seattle, noted participants were asked to recall depressive symptoms and OC use as far back as 20-30 years ago, which lends itself to inaccurate recall.
And the researchers didn’t ascertain whether the contraceptives had been used continuously or had been started, stopped, and restarted. Nor did they look at different formulations and doses. And the observational nature of the study “limits the ability to infer causation,” continued Dr. Oelschlager, chair of the American College of Obstetrics and Gynecology Clinical Consensus Gynecology Committee. She was not involved with the study.
“This study is too flawed to use meaningfully in clinical practice,” Dr. Oelschlager concluded.
The study was primarily funded by the Swedish Research Council, the Swedish Brain Foundation, and the Uppsala University Center for Women ‘s Mental Health during the Reproductive Lifespan. The authors, Dr. Rasgon, and Dr. Oelschlager declared no relevant financial relationships.
A version of this article first appeared on Medscape.com.