Freeman, D., Sheaves, B., Goodwin, G. M., Yu, L.-M., Nickless, A., Harrison, P. J., Emsley, R., Luik, A. I., Foster, R. G., Wadekar, V., Hinds, C., Gumley, A., Jones, R., Lightman, S., Jones, S., Bentall, R., Kinderman, P., Rowse, G., Brugha, T. . . . Espie, C. A. (2017). The effects of improving sleep on mental health (OASIS): A randomised controlled trial with mediation analysis. The Lancet Psychiatry, 4(10), 749–758. https://doi.org/10.1016/S2215-0366(17)30328-0

Type of Study: Randomized controlled trial
Number of Participants: 3,755

Population:

• Age — Mean=24.8 years
• Race/Ethnicity — 3081 White, 169 Mixed, 323 Asian, 81 Black, 26 Arab, and 43 Other
• Gender — 2,676 Female, 1,043 Male, and 36 Other
• Status — Participants were university students with insomnia.

Location/Institution: 26 UK Universities

Summary: (To include basic study design, measures, results, and notable limitations)
The purpose of the study was to determine whether treating insomnia leads to a reduction in paranoia and hallucinations. The primary aims were to evaluate participation rates and treatment acceptability, and to establish an effect size for symptom improvement. Participants were randomly allocated to cognitive behavioural therapy (CBT) for insomnia [now called Spark Direct] or usual care. Measures utilized include the Green et al Paranoid Thought Scales (GPTS), the Specific Psychotic Experiences Questionnaire—Hallucinations subscale, the Insomnia Severity Index (ISI), the Disturbing Dreams and Nightmare Severity Index, the 16-item version of the Prodromal Questionnaire, the Patient Health Questionnaire 9-item version (PHQ-9), the Generalized Anxiety Disorder 7-item version (GAD-7), the Altman Mania Scale, the Warwick–Edinburgh Mental Wellbeing Scale (WEMWBS), and the Work and Social Adjustment Scale (WSAS). Results indicate that compared with usual practice, the sleep at 10 weeks reduced insomnia, paranoia, and hallucinations. Insomnia was a mediator of change in paranoia and hallucinations. No adverse events were reported. Limitations include the study relied on self-report questionnaires; the samples tested were predominately in the nonclinical range of psychotic experiences, restricting the conclusions to the less severe end of the psychosis spectrum; participants were self-selecting in responding to the invitation, which will have affected the representativeness of the sample; the extent to which the results will generalize to the rest of the population is not known; and bias in the outcome results will have been introduced because of the high dropout rate, especially in the treatment group.

Length of controlled postintervention follow-up: 12 weeks.

Denis, D., Eley, T. C., Rijsdijk, F., Zavos, H. M. S., Keers, R., Espie, C. A., Luik, A. I., Badini, I., Derveeuw, S., Hodsoll, J., & Gregory, A. M. (2020). Is digital cognitive behavioural therapy for insomnia effective in treating sub-threshold insomnia: A pilot RCT. Sleep Medicine, 66, 174–183. https://doi.org/10.1016/j.sleep.2019.10.007

Type of Study: Randomized controlled trial
Number of Participants: 199

Population:

• Age — Mean=20 plus or minus 5 years
• Race/Ethnicity — 50% White, 38% Asian or Asian British, 18% Mixed Ethnicity, 14% Black or Black British, 13% Other, and 7% Arab
• Gender — 100% Female
• Status — Participants were female psychology students.

Location/Institution: Not specified

Summary: (To include basic study design, measures, results, and notable limitations)
The purpose of the study was to assess whether cognitive behavioral therapy for insomnia (CBT-I) [now called Spark Direct] is both feasible and acceptable in participants with sub-threshold insomnia. The primary aims were to evaluate participation rates and treatment acceptability, and to establish an effect size for symptom improvement. Participants were randomly allocated to either a six-week digital CBT-I intervention or a six-week control group receiving puzzles. Measures utilized include the Treatment acceptability questionnaire (TAQ), the Sleep condition indicator (SCI), the State Trait anxiety Index, the Mood and Feelings Questionnaire, the Attention Deficit Hyperactivity Disorder Symptoms Questionnaire, the Specific Psychotic Experiences Questionnaire, the Positive Mental Health Scale, the Perceived Life Stress scale, the Pittsburgh Sleep Quality Index, the Dysfunctional Beliefs and Attitudes about Sleep Questionnaire, the Pre-sleep Arousal Scale, and the Munich Chronotype Questionnaire. Results indicate that participation rates at each survey assessment wave did not differ between the groups, though adherence to completing each weekly task was lower in the CBT-I group, treatment acceptability was high. The CBT-I showed greater improvement in insomnia symptoms at the end of the intervention compared to the control group, with significant variation in outcome. Subthreshold participants showed a similar pattern of results, whilst those meeting insomnia criteria showed a smaller between-group difference. CBT-I led to improvements in anxiety, paranoia and perceived stress between baseline and end of intervention. Changes in insomnia symptoms were mediated by cognitions about sleep and somatic pre-sleep arousal. Limitations include lack of generalizability due to participant selection, control task may not have been ideally balanced to match the CBT-I, and did not collect any objective measurements of sleep (e.g. actigraphy or polysomnography).

Length of controlled postintervention follow-up: Approximately 18 weeks.