Diversity Inclusion in Clinical Trials Investigating Esketamine for Depression: A Systematic Review

Individuals of varying backgrounds may respond differently to pharmacological interventions for depression. The Food and Drug Administration (FDA) recently approved the drug, esketamine, for adults with treatment-resistant depression. The current systematic review was executed to assess diversity inclusion in clinical trials for esketamine. Pubmed and Embase were searched according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and the systematic review yielded 11 final studies. All resultant studies reported female inclusion, 10 studies (91%) reported partial racial and ethnic inclusion, two studies (18%) reported socioeconomic factors, five studies (45%) executed subgroup analyses, and two studies (18%) addressed diversity in their limitations. Females were generally well represented, whereas non-White and Hispanic/Latinx participants were consistently underrepresented. Socioeconomic representation could not be assessed due to underreporting of this factor. Overall, the present review reports on the representation of various demographic subgroups in clinical trials for esketamine in depression and offers suggestions for future research. Public Health Significance The present systematic review finds that non-White participants have been underrepresented and/or underreported in clinical trials investigating esketamine for depression, and that many studies do not address ethnic differences. This finding suggests that individuals from diverse or marginalized backgrounds may not be adequately represented in these trials, and clinical findings may not generalize to such populations.