Background: While second-generation antipsychotics (SGAs) effectively treat symptoms of hallucinations and mania with fewer neurologic side effects, 80% of youth experience ≥10% weight gain within six months of initiating an SGA. Clinicians acknowledge the critical need to manage this rapid weight gain, yet the uptake of adjunctive weight-loss medication (WTRx) is low, and there is limited evidence on when to initiate this preventive therapy in youth. Our preliminary findings showed an increase in WTRx uptake over time. In this study, we examined changes in time-to-initiation of WTRx from 2020 to 2024.

Methods: We conducted a new-user, retrospective cohort study using IQVIA PharMetrics® Plus Closed Health Plan claims data. Youth aged 5-21 years newly initiating an SGA (index date) from January 01, 2020, through June 30, 2024, with ≥6 months of continuous health insurance, and no SGA or WTRx use in the 6-month baseline period, were included. Beneficiaries were followed from the index date through December 31, 2024, to identify the first WTRx. Jonckheere-Terpstra test assessed trends in time-to-initiation. Multivariable generalized linear models assessed change in time-to-WTRx-initiation, adjusted for baseline covariates and stratified by sex.

Results: We included 954 (out of 26,936) youth who initiated WTRx; the majority were female (64.6%), older than 15 years (61.3%), on aripiprazole (48.9%), and prescribed metformin (86.6%). Only 4.9% co-initiated a WTRx. Median time to WTRx initiation decreased significantly from 2020 to 2024 (Fig. 1; p-trend<0.001). The time-to-WTRx-initiation ratio for each additional year, from 2020 to 2024, was 0.70 (95% CI: 0.63-0.77), with no significant difference by sex.

Conclusion: We observed a 30% reduction in the time-to-WTRx-initiation over the years. Studies in adults have shown that co-initiation, rather than initiation after SGA-induced weight gain, is more effective; thus, reducing the time to initiation is imperative in youth.