Study objective: There is continuing speculation about the relationship between attention-deficit/hyperactivity disorder (ADHD) and obstructive sleep apnea (OSA) or periodic limb movement disorder (PLMD)/restless legs syndrome. The objective was to determine if a significant portion of children with ADHD diagnosed using DSM-IV criteria have OSA or PLMD.
Setting: Sleep disorders centers in a private practice setting and a hospital setting.
Participants: Children aged 6 to 14 years with ADHD were enrolled. Patients with snoring were not excluded. Although patients with snoring plus either observed apneic episodes in sleep or excessive daytime sleepiness were to be excluded, as were patients with restless legs at night, only 1 subject actually had to be excluded because of these criteria.
Measurements and results: Forty children were evaluated with a polysomnogram. A respiratory disturbance index cut-off of more than 5 per hour of sleep was used to diagnose OSA, and a periodic limb movement (with arousal) index cut-off of 5 or more per hour of sleep was used to diagnose PLMD. The Attention-Deficit/Hyperactivity Disorder Rating Scale-IV-Parent Version: Investigator Administered and Scored was used to determine severity of inattentive, hyperactive, and total ADHD symptoms. Except for a somewhat longer rapid eye movement sleep latency and decreased percentage of rapid eye movement sleep, polysomnography was essentially normal. No patient had OSA or PLMD on polysomnography.
Conclusions: OSA or PLMD is not a common underlying disorder or etiologic factor in patients who meet the criteria for ADHD. In the absence of symptoms suggesting a primary sleep disorder, such as snoring with observed apneic episodes in sleep or daytime sleepiness or restless legs, polysomnographic evaluation does not seem indicated in patients with ADHD.