Objective: The Dutch law on youth care (the Youth Act) was implemented from 2015 onwards. One of the government’s aims by implementing this new policy was de-medicalization of youths by separating youth mental healthcare from the rest of the healthcare system. A previous study conducted by our research group showed that prevalence rates of antipsychotic drug prescriptions stabilized among Dutch youth in the period 2005–2015, just before the introduction of the Youth Act. In our study, we aimed to describe antipsychotic drug use among Dutch children aged 0–19 years old before and after implementation of the Youth Act (2010–2019). Methods: We analyzed prescription data of 7405 youths aged 0–19 years using antipsychotic drugs between 2010 and 2019, derived from a large Dutch community pharmacy-based prescription database (IADB.nl). Results: Prevalence rates of antipsychotic drug use per thousand youths decreased significantly in youths aged 7–12 years old in 2019 compared to 2015 (7.9 vs 9.0 p < 0.05). By contrast, prevalence rates increased in adolescent females in 2019 compared to 2015 (11.8 vs 9.5 p < 0.05). Incidence rates increased significantly in adolescent youths in 2019 compared to 2015 (3.9 vs 3.0 p < 0.05), specifically among adolescent girls (4.2 per thousand in 2019 compared to 3.0 per thousand in 2015). Dosages in milligram declined for the most commonly prescribed antipsychotic drugs during the study period. The mean duration of antipsychotic drug use in the study period was 5.7 (95% CI 5.2–6.2) months. Conclusion: Despite the aim of the Youth Act to achieve de-medicalization of youths, no clear reduction was observed in prevalence rates of antipsychotic drugs or treatment duration in all subgroups. Prevalence rates even increased in adolescent females.