Does Post-Exposure Napping Augment Fear Reduction in Phobic Youth?

Date

2018-12

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Abstract

Research has demonstrated that sleep has robust effects on learning and memory, but these benefits have yet to be applied in the context of therapy. The current study aims to extend the limited research on adult samples in this area to children. Method: Eleven children with a diagnosis of specific phobia were randomized into a post-exposure nap condition versus a wake condition. The primary aim of the study was to determine feasibility of a post-exposure nap using multimodal assessment of phobia severity at pre-treatment and 1-week and 1-month follow-ups. Children who napped following an exposure session were expected to demonstrate enhanced consolidation of extinction learning during therapy, therefore report less phobic severity and exhibit less reactivity and avoidance when re-exposed to the phobic stimulus. Additionally, objective sleep assessment data from polysomnography was examined to determine what characteristics of sleep are critical to these outcomes, data which will provide support for theoretical models. Results: One participant was unable to fall asleep during the post-exposure nap and was more subjectively and physiologically anxious during the task. Participants exhibited a high percentage of stage N3 sleep during the nap relative to other studies. Additionally, more rapid behavioral approach and higher subjective anxiety during recovery were significantly correlated with stage N2 sleep and greater spindle density. During the BATs, children reported higher anxiety when approaching more quickly, and participants who were more physiologically anxious approached more slowly. Generally, behavioral approach, subjective anxiety ratings, and heart rate and heart rate variability improved over time. However, findings indicated initial support for enhanced improvements in level of interaction with the stimulus, heart rate reactivity, and vagal HRV in the nap group. Slow wave sleep and sleep spindles were significantly related to improvements in diagnostic severity ratings provided by the clinician, subjective anxiety, and at least one variable representing HRV one week later. Discussion: This is the first study to demonstrate initial feasibility for post-exposure napping in clinically-anxious children, with all but one participant achieving a nap. It could be that children with higher levels of anxiety during treatment have more difficulty initiating sleep, but more data is needed. Although most participants did not achieve REM sleep, findings highlight the role of slow wave sleep and sleep spindles. This study has important clinical implications as napping may represent a cost-efficient and effective therapeutic tool for improving effectiveness of exposure-based psychotherapy and warrant replication in a larger and more diverse sample.

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Keywords

Child sleep, Specific phobia, Exposure therapy, Actigraphy, Polysomnography

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