Prevalence of attention deficit hyperactivity disorder and its relationship with sleep disorder among middle school students in Ningbo city

Objective To investigate the prevalence of attention deficit hyperactivity disorder(ADHD) and sleep disorder among middle school students in Ningbo city.Methods Stratified random cluster sampling was used to select 2 133 middle school students and their parents in Ningbo city for a self-administered questionnaire survey between May and June 2015 with a self-compiled questionnaire and Short Form,Parental Version of the Chinese Swanson,Nolan,and Pelham-IV(SNAP-IV);Insomnia Severity Index(ISI) was used to evaluate sleep status of the students.Results The proportions of the students with normal,critical,moderately abnormal,and severely abnormal SNAP-IV score for ADHD symptoms were 87.2%(1 861/2 133),9.3%(199/2 133),2.5%(54/2 133),and 0.9%(19/2 133),respectively;the boy students reported higher SNAP-IV score than the girl students(z=5.68,P < 0.01) and the students of low grade reported higher SNAP-IV score than the students of high grade (r_s=-2.02,P < 0.05).The proportions of self-reported insomnia were 20.63%(384/1 861),31.66%(63/199),37.04%(20/54),and 42.11%(8/19)for the students with normal,critical,moderately abnormal,and severely abnormal SNAP-IV score.The degree of ADHD was positively correlated to the severity of insomnia(H=4.36,P=0.00).There were no significant differences in the time of going to bed and getting up and the total sleep time among the students with different SNAP-IV score.The students with critical,moderately abnormal,and severely abnormal SNAP-IV score had higher total and domain ISI score than the students with normal SNAP-IV score.The scores of attention deficit and hyperactivity impulse score and overall ADHD score were positively correlated mildly with total ISI score.Conclusion The students with higher SNAP-IV score for ADHD symptoms had a higher incidence of insomnia and the result suggests that the intervention on insomnia could be adopted as one of measures for ADHD treatment.