National trends and correlates of treatment resistance in major depressive episode and associated suicidal ideation and behaviors among adults in the United States

Objective To examine recent 12-year trends in prevalence of suicidal ideation and behaviors (SIBs) among US adults experiencing a past-year treatment-resistant depression (TRD). Methods Using data from the National Survey of Drug Use and Health, we estimated the annual percentage of individuals aged ≥18 with TRD who reported past-year SIBs, and estimated linear trends adjusting for potentially confounding factors from 2009 to 2020. Results Of estimated 237.5 million US adults, 7.1 % met diagnostic criteria for a past-year major depressive episode (MDE) between 2009 and 2020. Of these, 9.7 % met criteria for TRD. The proportion reporting past-year suicidal ideation in TRD ranged from 39.5 % (95 % confidence interval [CI], 32.1–47.3 %) in 2009–2010 to 43.4 % (95 % CI, 36.7–503 %) in 2019–2020, with an average annual percent change (AAPC) of 1.3 % (95 % CI, −0.7 % to 3.3 %). The prevalence of past-year suicide attempts in TRD was 7.3 % across the study period (AAPC, 0.1 %; 95 % CI, −4.3 % to 4.7 %). Past-year SIBs were significantly associated with an increased likelihood of meeting criteria for TRD among adults with MDE (adjusted odds ratio [AOR], 1.53; 95 % CI, 1.35–1.75 for suicidal ideation; AOR, 2.17; 95 % CI, 1.79–2.62 for suicide attempts). No significant differences were observed between 2019 and 2020, reflecting the COVID-19 pandemic. Conclusion Among individuals with TRD, proportions of SIBs are high. These findings underscore an urgent need for suicide prevention efforts in this high-risk population, including preventive services across diverse settings and accessibility to evidence-based pharmacological and non-pharmacological interventions.