Associations between psychiatric comorbidities and sleep disturbances in children with attention-deficit/hyperactivity disorder

Abstract

Objective: Children with attention-deficit/hyperactivity disorder (ADHD) often have sleep complaints and also higher rates of psychiatric comorbidities such as mood and anxiety disorders that may affect sleep. The authors hypothesized that children with ADHD and psychiatric comorbidities would have higher overall sleep disturbance scores as measured by a sleep questionnaire than children with ADHD without comorbidities.

Methods: This cross-sectional analysis in an academic center studied 317 children with ADHD; 195 subjects had no comorbid conditions, 60 were anxious and 62 were depressed. Participants completed the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present State, 4th Revised Edition and the Children's Sleep Habits Questionnaire.

Results: Median age (range) was 8.9 (6-18.7) years; 78% were male. Median (interquartile range) Total Sleep Disturbance Score (TSDS) on Children's Sleep Habits Questionnaire for subjects with no comorbidities was 44 (40-49); anxiety, 48 (43-54); and depression, 46 (41-52). Compared with subjects without comorbidities, TSDS in anxious subjects was greater (p = .008). TSDS in depressed subjects was not significantly different. Compared with subjects without comorbidities, anxious subjects had higher Bedtime Resistance, Sleep Onset Delay, and Night Wakings subscales (p = .03, .007, and .007, respectively); depressed subjects had higher Sleep Onset Delay and Sleep Duration subscales (p = .003 and .01, respectively).

Conclusions: Anxiety in children with ADHD contributed to higher overall sleep disturbance scores, compared with children with ADHD alone. Both comorbidities were associated with higher Sleep Onset Latency subscale scores. Further study of the impact of psychiatric comorbidities on sleep in children with ADHD is warranted.

Figure 1. CSHQ subscales differing between comorbidities and no comorbidities

Several Children’s Sleep Habits Questionnaire (CSHQ) subscales differ between subjects with and without comorbidities, as shown in these box plots. In box plots, the line within the box marks the median. The boundary of the box closest to zero indicates the 25th percentile and the boundary of the box farthest from zero indicates the 75th percentile. Whiskers above and below the box indicate the 90th and 10th percentiles. Outlying points are also marked. Anxious subjects had higher scores compared with those without comorbidities on Night Wakings and Bedtime Resistance subscales (P = 0.007 and 0.03, respectively). Depressed subjects had significantly higher scores compared with those without comorbidities on Sleep Duration subscale (P = 0.01). Sleep Onset Delay subscale results are displayed in histograms. Both anxious and depressed subjects differed significantly from those without comorbidities on the single question Sleep Onset Delay subscale, with higher proportions reporting longer sleep onset (P = 0.007 and 0.003, respectively).