Sleep Quality in Children and Adolescents with Autism Spectrum Disorder with and without Anxiety Compared to Typically Developing Children

Background: One of the most common medical conditions in children with ASD is chronic severe insomnia, with a prevalence estimate of 60-80% (Wiggs and Stores, 2004, Souders et al , 2009). This is a 2-3 fold increase over typical developing children (TDC).  Adequate  sleep is critical for the most advantageous neurobehavioral and physiological development and functioning (Banks and Dinges, 2007, Goel, et al, 2009). Inadequate sleep has been shown to have detrimental effects on cognition, behavior, mood, and attention (Gozal, 1998, Maquet, 2001).   The core deficits of ASD, and their underlying neurobiology, may predispose children with ASD to intrinsic and extrinsic factors that threaten sleep.  There are many possible causes of sleep disturbances in ASD, however, the two predominant sleep disorders in ASD are behavioral insomnia and insomnia secondary to their ASD (Wiggs and Stores, 2004, Souders et al , 2009). One hypothesis for intrinsic insomnia in ASD is that synaptic pathway anomalies alter levels of excitory neurotransmitters (Bourgeon, 2007). This arousal dysregulation may be the underlying mechanism of the high levels of anxiety, fears and hypersensitivity to environmental stimuli experienced in ASD and may contribute to difficulties initiating and maintaining sleep.  Anxiety is considered a part of the arousal continuum and to date we have limited understanding of the relationship between anxiety symptoms in ASD and insomnia.

Objectives: The purpose of this study is to investigate the nature of the relationship between anxiety symptoms and sleep in children with ASD as compared to TDC.

Methods: Thirty one of the projected sample of 50 children with ASD, ages 6-17, were recruited from a larger funded study and compared to 8 of the projected sample of 50 TDC.   The subjects had general cognitive function testing and ASD diagnose confirmed by ADOS/ ADI.  The anxiety symptoms were evaluated by the neuropsychology team utilizing the Anxiety Diagnostic Interview Schedule (ADIS- C/P), child and parent version , a two hour structured interview, and anxiety questionnaires. Sleep was characterized by 5-7 nights of an objective measure, actigraphy using the Sadeh algorithm, sleep diaries, sleep questionnaire and a comprehensive medical interview by the nurse researcher. 

Results: A  DSM-IV-TR anxiety diagnosis was identified with the ADIS-C/P in 18 of the 31 ASD subjects (58%).  One ASD subject met criteria for Anxiety Disorder- NOS.  One of the 8 TDC was identified with a specific phobia.   Insomnia was identified in 51% of the ASD, defined as a  sleep latency greater than 30 minutes by actigraphy.  No TDC were identified with insomnia.    We found significant differences in sleep latency (p= .oo4), sleep efficiency (p=.049) and wake in minutes (p=0.014) and a trend in sleep minutes (p=.064) when comparing ASD children with anxiety (n=19) and without anxiety (n=12).  Moreover, we found no significant difference in the four sleep parameters between the TDC and the ASD group without anxiety.

Conclusions: This preliminary data suggests that anxiety and insomnia are linked.  We hope after the completion of this study we will provide insights into the co-treatment of anxiety and insomnia in ASD.