Harnessing the Power of Sex Differences: What a Difference Ten Years Did Not Make

Sex differences exist in many neurological and psychiatric diseases. Mandates have been initiated across funding agencies for research to include males and females. What has been lacking in the literature is a detailed assessment of how sex is incorporated into the design (e.g. balanced design) and into the analyses (e.g. covariate). We surveyed papers in 2009 and 2019 across six journals in Neuroscience and Psychiatry. There was a 30% increase in the percentage of papers that included both sexes to 68% in 2019. Despite this increase, in 2019 only 19% of studies used an optimal design for discovery of possible sex differences and only 5% analyzed sex as a discovery variable. Here we show that little progress has been made in harnessing the power that sex differences can afford in research for discovery and therapeutic potential for neurological and psychiatric disease to improve the health of men, women and gender diverse individuals. Highlights68% of Neuroscience and Psychiatry papers reported the use of both sexes in 2019 Only 19% of studies in 2019 used sex consistently throughout the study analyses Of the studies that used males and females, 59% did not include sex in the analyses Only 5% of studies in 2019 used sex as a discovery variable in their analyses Male only papers were 8.4 times more prevalent than female-only papers