Pharmacoepidemiology of antipsychotic use in youth with ADHD: trends and clinical implications

Although concern has been raised about antipsychotic prescribing to youth with attention-deficit/hyperactivity disorder (ADHD), the available database is limited to individual studies. Therefore, in order to provide a synthesis of prevalence and time trends, we conducted a systematic review and pooled analysis of pharmaco-epidemiologic data on antipsychotic use in ADHD youth. Of 1806 hits, 21 studies (N) were retained that reported analyzable data for three separate populations: 1) antipsychotic-treated youth (N = 15, n = 341,586); 2) ADHD youth (N = 9, n = 6,192,368), and 3) general population youth (N = 5, n = 14,284,916). Altogether, 30.5 ± 18.5% of antipsychotic-treated youth had ADHD. In longitudinal studies, this percentage increased over time (1998-2007) from 21.7 ± 7.1% to 27.7 ± 7.7%, ratio = 1.3 ± 0.4. Furthermore, 11.5 ± 17.5% of ADHD youth received antipsychotics. In longitudinal studies, this percentage also increased (1998-2006) from 5.5 ± 2.6% to 11.4 ± 6.7%, ratio = 2.1 ± 0.6. Finally, 0.12 ± 0.07% of youth in the general population were diagnosed with ADHD and received antipsychotics. Again, in longitudinal studies, this percentage increased over time (1993-2007): 0.13 ± 0.09% to 0.44 ± 0.49%, ratio = 3.1 ± 2.2. Taken together, these data indicate that antipsychotics are used by a clinically relevant and increasing number of youth with ADHD. Reasons for and risk/benefit ratios of this practice with little evidence base require further investigation.