Examining Treatment of Race in the Relationship between C-reactive protein and Depression

Presenter(s): Leticia Hayes − Psychology

Faculty Mentor(s): Sarah Horn

Poster 98

Research Area: Social Science

Background: Race is increasingly recognized as a significant moderator in the relationship between inflammation and major depressive disorder (MDD). However, race is often unreported or treated as a nuisance variable. Methods: A systematic review was conducted to explore how race was treated in studies examining the inflammatory marker C-reactive protein (CRP) and MDD using key search terms (e.g., CRP, depression). A total of 192 articles were yielded through PubMed and Google Scholar. Studies were coded for several themes including effect size and race. A meta-analytic approach was also employed to explore the strength of and levels of heterogeneity in the association between CRP and MDD across major geographic areas (e.g., North America, Asia). Results: A total of 143 studies did not report the race and ethnicity break-down of their sample or only reported the country in which the study was conducted. Only 13.5% of studies explicitly controlled for race in their model and one study excluded African-American participants. Most studies were conducted in Western European countries (55%) with predominantly Caucasian populations or in the United States (US; 30%). Aggregated effect sizes were small (~r=.06), but comparable across geographic areas; however, heterogeneity varied widely. Conclusion: Race is often unreported in studies testing associations between CRP and MDD and only a small subset of studies statistically adjusted for race effects in the various models. Further, the majority of the studies were conducted in Western countries. It is imperative that future research collect, report, and consider race in models examining inflammation and MDD.