Digital Cognitive Behavior Therapy for Insomnia Compared With Digital Patient Education About Insomnia in Individuals Referred to Public Mental Health Services in Norway

Sleep is a fundamental human need with large impact on both psychological and somatic functioning. However, for patients with mental disorders, sleep is often disturbed. Across all diagnostic groups, sleep disturbance is one of the most common and disruptive symptoms. For decades it has been assumed that the sleep disturbance these patients experience was a secondary symptom of a primary mental disorder, but recently this has changed. Experimental and clinical data now suggest that there is a reciprocal relationship between sleep disturbance and mental disorders where they perpetuate and aggravate each other. This makes sleep disturbance a potential therapeutic target in the treatment of mental disorders. Evidence emerging the last decade indicate that providing Cognitive Behavior Therapy for Insomnia (CBT-I) to patients with mental disorders not only improves sleep, but also has clinically meaningful effects on their primary mental disorder. However, a major problem has been disseminating CBT-I and few therapists are trained in this intervention. Consequently, most patients receive sleep medication although evidence clearly indicate that CBT-I is more effective and should be the treatment of choice. In this study, the investigators will use a fully automated digital version of CBT-I that might be used to treat a large number of patients while they are still on the waiting list to receive ordinary outpatient treatment in secondary mental health care clinics in Norway. The main goal is to test the effectiveness of digital CBT-I for this patient group.

(27th May 2021) We have revised one of the study exclusion criteria. In the initial protocol we reported that we would exclude individuals with clinical evidence of sleep apnea, namely, we stated that: "Sleep apnea screening: An Epworth Sleepiness Scale (ESS) score \>=13, indicative of high levels of objective daytime sleepiness associated with organic sleep disorders and/or positive endorsement of a screening question for sleep apnea (the item asks if they "usually or everyday snore and stop breathing and have difficulties staying awake during the day")." We have now modified the exclusion criterion, so that it is based on the screening question alone. Our updated exclusion criterion is now stated as follows: "Sleep apnea screening: A positive endorsement of a screening question for sleep apnea (the item asks if they "usually or everyday snore and stop breathing and have difficulties staying awake during the day")." i.e. the ESS score is no longer part of the assessment for eligibility for inclusion. The rationale for this change is that several publications and international experts have questioned the reliability and validity of the ESS cut-off score (\>=13) when the scale is used in psychiatric outpatient populations (psychometrics in clinical samples are only modest when compared with ESS for screening community-based and/or non-clinical samples). As such ESS score is no longer used as an exclusion criterion, but we will continue to collect these data at baseline assessment and will report the ESS scores for the recruited sample.

At the time of making the amendment, 29 participants had been excluded on the basis of the ESS score.

(27th Feb, 2023): In the protocol that was approved by the Regional Committees for Medical and Health Research Ethics before inclusion started, under 'sample size', we wrote: "As the planned RCT involves limited contact between researchers and participants and has a 12-month follow-up, we have predicted that the study dropout rate is likely to reach about 50%. Therefore, we aim to recruit 800 participants, to enable us to retain 400 patients (200 in each treatment arm) at the end of the RCT."

We have now included 790 participants in this trial, and the attrition rate at the 12 month follow-up assessment is somewhat higher than predicted before we started the trial. Currently, 46% of the participants have completed the 12 month follow-up assessment. Based on this, we will not reach the target of retaining 400 participants at the end of the RCT with a sample size of 800 participants.

We have described the situation to the Regional Committees for Medical and Health Research Ethics. They have approved inclusion of new participants until June 30th 2023. This has been presented to the leaderships of the participating centers who also have approved inclusion until June 30th 2023. We will therefore recruit participants until this date. Based on our projections we will have retained at least 404 participants at the end of the RCT at this date.

Eligibility Criteria:
Inclusion Criteria:

* Willing and able to provide written informed consent.
* Insomnia Severity Index (ISI) \> 11 We have used this cut-off score previously to identify individuals who are likely to be experiencing clinical significant insomnia and who will potentially benefit from the dCBT-I intervention. Kallestad et al 2018 and a trial from Norway (Filosa et al in press) suggest that this cut-off is the most sensitive to detect a diagnosis of Insomnia Disorder.

Exclusion Criteria:

1. Sleep apnea screening: Positive endorsement of a screening question for sleep apnea (the item asks if they "usually or everyday snore and stop breathing and have difficulties staying awake during the day")
2. Medical history indicative of (i) epilepsy plus self-report of \>=1 seizure \<12 months ago, or (ii) recent surgery for heart disease, or (iii) currently in an attack phase of multiple sclerosis.
3. Individuals whose work schedule includes night shifts.
4. Pregnancy
5. Inadequate opportunity to sleep or circumstances prevent modification of sleep pattern (e.g. having a child aged\<12 months residing home).
6. Currently receiving psychological treatment for insomnia.
7. Not a patient at one of the participating clinics.
8. Not having completed baseline assessment