LAUSR

Individuals with insomnia often show subjective-objective sleep discrepancy, especially an overestimation of their sleep onset latency (SOL) while the factors associated with such discrepancy remained unclear. Whilst cognitive behavioral therapy for insomnia (CBT-I) has been recommend as the first-line treatment for insomnia, there has been limited research to investigate the effects of CBT-I on sleep onset perception in youths with insomnia. The present study aimed to identify potential variables related to sleep onset misperception and explore the effects of CBT-I on sleep onset misperception among youths with insomnia. Sixty treatment-seeking youths with insomnia (mean: 19.74 ±2.42, female: 55%) were recruited to assess for their sleep and clinical characteristics using self-report questionnaires and 7-days sleep diary and actigraphy (T1). A subset of the sample (N=19) further completed an 8-week CBT-I programme and assessed at one-week post-treatment (T2) and 6-month follow-up (T3). Sleep misperception index was computed by subtracting actigraphy-measured SOL from sleep diary reported SOL, where a higher value indicates a higher degree of SOL overestimation. Demographic, clinical and sleep-related variables were compared between high versus low sleep onset misperception groups as divided by the mean of the sample. Changes in sleep onset misperception after CBT-I were analyzed using repeated measures ANOVA. High sleep onset misperception group demonstrated a significantly higher degree of anxiety symptoms (t(28)=-3.92, p<.01) and pre-sleep cognitive arousal (t(28)=-0.49, p<.05) as compared to low sleep onset misperception group. Participants who completed CBT-I showed a significant decrease in subjective-objective SOL discrepancy (T1=19.52, T2=6.96, T3=-1.37). A post-hoc pairwise comparison using the Bonferroni correction suggested a significant decrease in subjective-objective SOL discrepancy from T1 to T3 (p<.05). Significant improvement in pre-sleep cognitive arousal was found from T1 to T3 (<.001) and such an improvement was found to be significantly correlated with the reduction in sleep onset misperception (r=0.16, p<.05). Sleep onset misperception is associated with anxiety symptoms and pre-sleep cognitive arousal in youths with insomnia. Preliminary evidence supports that CBT-I is effective in improving sleep onset misperception in youths with insomnia. Future research should explore the neurophysiological mechanism underlying sleep onset misperception and the changes of such a discrepancy upon intervention.