Gender and Socioeconomic Dimensions of Relative Age Effects on ADHD Prescriptions: Evidence from Denmark

Abstract

This paper examines the impact of relative age on Attention Deficit Hyperactivity Disorder(ADHD) prescriptions among school-aged children. Using a regression discontinuity design,we leverage the quasi-experimental variation in school starting age. We use administrativedata for all children aged 6-16 from 2010 to 2019 in Denmark. We find a significant decreasein ADHD prescription rates for girls, who are relative old compared to their class mates. Wedo not find any significant results for boys. We further test the social gradient in relative ageon ADHD prescriptions, and find that the effect is entirely driven by girls from low incomefamilies.

Keywords: ADHD, misdiagnoses, children, gender, socio-economic outcomes