Young Adult Depression, Antidepressant Prescriptions, and Therapy Intensification in People With Incident Depression in the United States.

To evaluate the temporal trend in young adult depression, prescription patterns of first- and second-line antidepressants, and factors influencing therapy intensification for depression stratified by sex. A retrospective cohort of people aged ≥ 18 years with incident depression between 2006 and 2017 was extracted from the Centricity Electronic Medical Records. Among 2,201,086 people with depression (82% on antidepressants), the mean age was 47 years, 29% were male, 40% had cardiometabolic multimorbidity, and 32% were diagnosed at age < 40 years (young adult depression). Prevalence of young adult depression increased significantly from 26% to 36% with a higher proportion in females compared to males (34% vs 26%) between 2006 and 2017. Selective serotonin reuptake inhibitors (SSRIs) were the most prescribed first-line antidepressant (56%), with a prescribing rate increase from 47 per 1,000 person-years to 81 per 1,000 person-years. Among first-line antidepressant recipients, 23% had treatment intensification after a median of 17 months. Compared to those aged 60-70 years, younger males and females had a similar significantly higher treatment intensification risk (range of hazard ratio [HR], 1.09-1.46). Cardiometabolic multimorbidity was associated with a 2% (HR CI, 1.01-1.05) and 7% (HR CI, 1.05-1.09) higher treatment intensification risk in males and females, respectively, while anxiety increased the treatment intensification risk by 63% (HR CI, 1.57-1.68) in males and 57% (HR CI, 1.52-1.62) in females. Non-Whites and SSRI initiators had lower risks of treatment intensification (all HR CI < 1). More than one-third of US adults with depression are aged < 40 years with an increasing trend among females. The temporal antidepressant prescribing rates were similar between sex, while significant ethnic disparity in therapy intensification was observed between sex.