Clinical Characteristics of Patients with Autism Spectrum Disorder Referred to a Pedopsychiatric Sleep Clinic

Background: Sleep disorders are frequent in children with an Autism Spectrum Disorder (ASD), with prevalence estimates as high as 80%. Even though sleep disorders increase diurnal symptoms and constitute a significant burden for the entire family, little is known about the clinical characteristics of these children.

Objectives: To describe the clinical characteristics of 250 ASD children referred to a specialized pedopsychiatric sleep clinic.

Methods: We reviewed the medical charts of 250 children with ASD referred to the sleep clinic of a child psychiatry hospital (mean age = 10.8±2.9 years, 76.8% boys). Specialty of the referring physician, diagnoses, medication and scores on the Children Sleep Habits Questionnaire (CSHQ) upon arrival, as well as sleep disorders after assessment at the clinic were extracted for analyses.

Results: The majority of patients were either referred by a pediatrician (42.8%) or a psychiatrist (38.4%). Half of patients (52.0%) had another diagnosis, the most frequent being Attention Deficit Hyperactivity Disorder (20.0%) and Intellectual Disability (12.0%). Upon arrival to the sleep clinic, 112 patients (44.8%) were taking prescribed medications, the most frequent being psychostimulants (18.8%), antipsychotics (12.4%), and antidepressants (10.4%); more specifically at bedtime, antipsychotics were the most frequent prescribed medication while 119 patients (47.6%) were taking melatonin. Among the 145 patients who filled the CSHQ, 138 (95.2%) reached or exceeded the clinical cut-off score of 41; the total observed scores ranged from 33 to 74. The most frequent confirmed sleep disorder was insomnia (21.6%), followed by parasomnias (9.6%): somniloquy (6.8%), bruxism (6.0%), restless legs syndrome or periodic limb movements during sleep (5.2% and 7.2%, respectively), obstructive and central sleep apnea (2.0% and 1.6%, respectively), somnambulism (2.0%) and confusional arousals (2.0%). Atypical EEG during sleep was found in 2.8%. There were no confirmed cases of hypersomnia or narcolepsy, circadian disorders or nocturnal eating disorders.

Conclusions: These data point towards salient features of ASD children presenting at a sleep clinic: most referring MDs are specialists, half the ASD patients have at least one additional psychiatric diagnosis, and the most frequent sleep disorder is insomnia. The proportion of patients with insomnia clearly exceeds the prevalence published for neurotypical children, while the prevalence of sleep apnea is similar to published prevalence in the general pediatric population. Antipsychotics being the most prescribed medication at bedtime is worrisome.