Objective  To investigate influencing factors for comobidity of attention-deficit/hyperactivity disorder (ADHD) and sleep disorder among adolescents．

  Methods  We a conducted survey on ADHD and sleep disorder among 2 133 students selected with stratified random cluster sampling from 6 high schools in 3 county-level regions in Ningbo city of Zhejiang province during May and June 2015. The Chinese Version Swanson, Nolan, and Pelham Scale-Version IV (SNAP-IV) was used for the diagnosis of ADHD; the Insomnia Severity Index (ISI) was used to assess sleep status of the students; and the Self-Rating Anxiety Scale (SAS) , Self-Rating Depression Scale (SDS) , and a self-designed questionnaire were adopted to collected relevant information in the students. Then the 272 students identified with ADHD were assigned into a non-sleep disorder (NSD) group (n = 181) and a sleep disorder (SD) group (n = 91) for comparison analysis. Logistic regression analysis was performed to explore influencing factors of comobidity of ADHD and sleep disorder.

  Results  For all the 272 students with ADHD, the average age of the NSD group was younger than that of SD group (14.27 ± 1.15 vs. 14.62 ± 1.10) ; the proportion of the students with difficulty in coping with learning stress was higher for the SD group than that for the NSD group (13.2% vs. 5.0%) ; the ratio of the students with maternal education of undergraduate or above was higher in NSD group than that in SD group (22.1% vs. 14.3%) . Compared to those in the SD group, lower scores for attention deficit (14.88 ± 3.95 vs. 16.21 ± 4.25) , anxiety (31.67 ± 7.56 vs. 38.31 ± 9.20) , and depression (11.42 ± 8.23 vs. 21.41 ± 9.83) were observed in NSD group; whereas there were significant differences in scores for hyperactivity disorder and oppositional disobedience between the two groups. The results of logistic regression analysis indicated that age and high scores for attention deficit, anxiety, and depression were risk factors for the comobidity of ADHD and sleep disorder among the adolescents.

  Conclusion  The comobidity of ADHD and sleep disorder are correlated with symptoms of attention deficit, anxiety and depression among high school adolescents and comprehensive strategies should be developed in interventions on sleep disorder among the adolescents.