Selective Serotonin Reuptake Inhibitors, Serotonin-Norepinephrine Reuptake Inhibitors and Migraine: Should Cochrane Close the Door?

Abstract

The Cochrane Collaboration completed a review entitled “Selective Serotonin Reuptake Inhibitors (SSRIs) and Serotonin-norepinephrine Reuptake Inhibitors (SNRIs) for the Prevention of Migraine in Adults” in 2015. In the review, they acknowledge that poor-quality research and low levels of evidence make it difficult to draw definitive conclusions, but then state that “A randomised controlled trial comparing a SSRI or a SNRI versus another drug or another non-pharmacological intervention is not a priority in the migraine research pipeline and might not exert a significant impact on the overall evidence”. A detailed evaluation of 10 of the 11 papers analysed in the Cochrane Review reveals that 9 of them use the International Classification of Headache Disorders (ICHD) system to determine their study cohorts. Despite being the current globally accepted standard for classification, diagnosis and categorization of migraine, the ICHD criteria are based on an arbitrary symptom list and offer little, if any, insight into the possible mechanisms involved in the pathophysiology of a migraine. Using the ICHD system in scientific studies which investigate the prevention and treatment of migraines, including those analyzed by the 2015 Cochrane Review, therefore results in amorphous cohort selection for those studies. This directly impacts the clinical relevance of the results drawn from the research. We acknowledge, and are grateful for, the important and highly credible contribution that the Cochrane Collaboration brings to our body of scientific knowledge. We are, however, concerned that the conclusions drawn in this important review might negatively impact on clinician ability to help individual migraine patients, not through any fault of the Cochrane Collaboration review system, but due to a fundamental flaw in the classification of migraines.