Objective: To outline specific sleep disturbances in different clinical subsets of Attention Deficit/Hyperactivity Disorder (ADHD) and to confirm, by means of nocturnal video-polysomnography (video-PSG), a variety of sleep disorders in ADHD besides the classically described periodic leg movement disorder (PLMD), restless legs syndrome (RLS) and sleep related breathing disorder (SRBD).
Methods: Fifty-five ADHD children (47 M, 8F; mean age=8.9 y) were included: 16 had Inattentive and 39 Hyperactive/Impulsive or Combined ADHD subtype. Behavior assessment by Conners and SNAP-IV Scales, a structured sleep interview and a nocturnal video-PSG were administered.
Results: Most children/parents reported disturbed, fragmentary sleep at night; complaints were motor restlessness (50%), sleep walking (47.6%), night terrors (38%), confusional arousals (28.5%), snoring (21.4%), and leg discomfort at night associated with RLS (11.9%). There is a significant difference (p value <0.05 or <0.001) in almost all the studied sleep variables between ADHD children and controls. International RLS Rating Scale scoring, Periodic Limb Movements during Sleep (PLMS) and Wake (PLMW) indexes, hyperactivity and opposition scores and ADHD subtype appear related. Different sleep disorders seem to address specific ADHD phenotypes and correlate with severity of symptoms as in sleep related movement disorders occurring in Hyperactive/Impulsive and Combined ADHD subtypes. Besides, an abnormality of the arousal process in slow wave sleep with consequent abnormal prevalence of disorders of arousal possibly enhanced by SRBD has also been detected in 52% of our sample.
Conclusions: This study underlines the opportunity to propose and promote the inclusion of sleep studies, possibly by video-PSG, as part of the diagnostic screening for ADHD. This strategy could address the diagnosis and treatment of different specific ADHD phenotypic expressions that might be relevant to children's symptoms and contribute to ADHD severity.