Sleep and Daytime Functioning in Children on the Autism and Fetal
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Sleep and Daytime Functioning in Children on the Autism and Fetal Alcohol Spectrums Rabya Mughal Thesis submitted for the degree of Doctor of Philosophy The UCL Institute of Education Prepared under the supervision of Dr. Dagmara Dimitriou and Dr Catherine M. Hill Acknowledgements I would like to thank my supervisors, Dr Dagmara Dimitriou and Dr Catherine Hill for their invaluable expertise and guidance throughout this process. Dr Anna Joyce, Professor Chloe Marshall, Dr Maria Kambouri, and the members of the Lifespan Learning and Sleep Laboratory at the UCL Institute of Education have kindly contributed their valuable time and knowledge to discussing the important topics and making students feel supported, for which we are all grateful. I would like to thank the UK FASD Alliance, in particular Maria Catterick who went above and beyond in order to facilitate this study in the hope it may help children with FASD. To Pip Williams, may she rest in peace, for welcoming me to the UK Birth Mothers Network and giving me a stark and eye- opening introduction to the complexities of this subject, which was her lifelong work. I am indebted to the 322 children and their mums, dads, grans, foster parents, uncles and aunties who contributed to the content of this thesis in the hope that we might be able to move forward in the research on Autism and FASD. And to my husband Samy: for all your continuous kind help, love, support, and comedy, thank you. Impact Statement/ General Summary Autism and Fetal Alcohol Spectrum Disorders (FASD) are neurodevelopmental conditions that affect at least 3% of the school aged population. Both have serious secondary sequelae including anxiety and depression, problems with concentration in class, learning new concepts through relevant curriculums, and social communication. Sleep is crucial to healthy neurodevelopment. It is not just a period of rest, but a time when the brain is highly active. During sleep, the brain consolidates newly acquired information, organises memory, and can lay the basis for emotional memory. Within Autism and FASD (as well as in many other developmental and psychological conditions), sleep quality and quantity remain much lower than the average and necessary amount. It is not known why this is, but research suggests that there is a complex and bidirectional relationship between sleep and development. This relationship may be part of the compromise of atypical development. This thesis links sleep with a number of daytime outcomes in children with Autism and FASD. According to the research carried out as part of this thesis, sleep is connected to anxiety, behaviours such as aggression and withdrawal, cognitive aspects such attention and working memory, as well as social and environmental factors. This is apparent not only in children in the neurodevelopmental categories, but in typically developing children too. This research also finds that children with Autism and FASD experience more sleep problems than typically developing children. It is therefore proposed here that sleep health interventions should be strongly considered as part of the therapeutic practice for children with Autism and FASD. Thesis Overview This thesis makes a novel contribution to developmental psychology by examining the associations between sleep and daytime functioning in children with Autism Spectrum Conditions (Autism, or ASC) and Fetal Alcohol Spectrum Disorders (FASD). Poor sleep is consistently noted as a secondary sequela in the developmental profiles of both Autism and FASD, and there is evidence that sleep plays a part in atypical and typical neurodevelopmental processes. Although it is not fully known, evidence suggests that causal, bidirectional relationships between sleep and neurodevelopment can explain some of the cognitive manifestations of Autism and FASD. The purpose of this thesis therefore is to examine the extent of the relationship between sleep, anxiety, executive functioning, behaviour, working memory attention, fluid intelligence and receptive vocabulary in these two neurodevelopmental conditions. Chapter 1: This thesis begins with a literature review of the neuropsychological aspects of sleep, particularly within the context of developmental processes. There is also a focus on the developing fetus and the impact of pre and postnatal environments on later cognitive outcomes. This is followed by a review of the literature on Autism and FASD. Chapter 2: The first study of this thesis examines the associations between sleep, anxiety, behaviour and executive functioning. Two hundred and seventy-nine caregivers completed the Children’s Sleep Habits Questionnaire (CSHQ), the Behavior Rating Inventory for Executive Functioning (BRIEF), the Spence Children’s Anxiety Scale (SCAS), the Child Behavior Checklist (CBCL), and a socioeconomic (SES) questionnaire. Participants were caregivers of children aged between 6-16-years with a diagnosis of FASD (n=114) or Autism (n=61). An additional sample of typically developing (TD) children were also assessed (n=104). Multiple regression analysis revealed that, according to parental report, sleep was a predictor of anxiety, behaviour and executive functioning in all three groups. Tests of similarity showed significantly similar behavioural and anxiety scores between children with Autism and FASD, with both clinical groups appearing to show similar levels of panic, physical injury concerns, separation anxiety, generalised anxiety, composite anxiety scores, and levels of withdrawn behaviour. Meanwhile, executive functioning and non-adaptive behaviours were significantly different between the three groups, with several subsets scoring higher than clinical cut off points, indicating the need for clinical intervention. This statistical difference between the three groups is conceptualised within this thesis as ‘syndrome specificity’ and is discussed further. Chronological age, sex and SES were also predictors of sleep and daytime functioning within the statistical model. Chapter 3: The second study of this thesis examines sleep and cognition using objective procedures: actigraphy, measuring sleep bouts and activity during the night; a Choice Reaction Time (CRT) task measuring sustained attention and inhibition; a digit span task measuring working memory; the Ravens Standard Progressive Matrices (RSPM) measuring fluid intelligence, and the British Picture Vocabulary Scale (BPVS) as a measurement of receptive vocabulary (the latter two for the purpose of understanding the child’s verbal and nonverbal mental age [MA]). Participants were children aged between 6-12-years with either a diagnosis of FASD (n=29) or Autism (n=21). An additional sample of typically developing (TD) children were selected as a comparison group (n= 46). Group comparisons revealed that children in the clinical groups experienced shorter sleep duration and more sleep fragmentation than the TD group. Chronological age (CA), MA, sex and SES were predictors of cognitive tasks and sleep. Multiple regression analysis revealed that sleep problems were predictors of cognitive outcomes in all three groups. Statistical comparisons between Study 1 and Study 2 showed there was a disparity between subjective and objective measurements of sleep. Whilst both methods of ascertaining sleep characteristics carry their own limitations, it was noted that such disparity may affect results and future studies on sleep in neurodevelopmental conditions should take this into account. Chapter 4: This thesis concludes with a discussion of the role of sleep in Autism and FASD, implications of findings and areas for further investigation. Both subjective and objective measurements revealed significantly poorer sleep in the two clinical samples. Sleep disturbances as measured by caregiver questionnaire and actigraphy were significantly associated with some of the core cognitive and behavioural profiles of children with Autism and FASD. It is therefore suggested that sleep is an important target for intervention and further research is required within this field. A note on Language The language used in this thesis complies with the identity-first language preferred by the Autism community, and the person-first language preferred by the FASD community. Whilst the word ‘condition’ is preferred to ‘disorder’ in the Autism community, this differentiation is not prioritised in the FASD community. Within this thesis, Autism is referred to as Autism Spectrum Condition (ASC) or simply ‘Autism’. Fetal Alcohol Spectrum Disorder is referred to as FASD (American Psychological Association, 2020; National Autistic Society, 2020). The American spelling of ‘Fetal’ is used throughout this thesis since this is both the medical spelling of the word and the agreed spelling amongst the UK FASD research community. 1.1 Sleep .......................................................................................................................................9 1.1.1 Sleep architecture....................................................................................................... 10 1.1.2 Sleep and development .............................................................................................. 13 1.1.3 Process S and Process C .............................................................................................. 17 1.1.4 The functions of sleep ................................................................................................ 18 1.1.5 Sleep disorders in typical development ....................................................................