An interventional study of Immediate CBCTi and Delayed CBCTi in Insomnia Chronic and Anxiety, sponsored by Woolcock Institute of Medical Research. Recruiting at 1 site in Australia. Open to participants aged 18 Years to 45 Years. Per ClinicalTrials.gov, last updated 2025-11-26.
Sponsored by Woolcock Institute of Medical Research · Not applicable, Interventional, and Treatment
This project aims to elucidate whether CBCTi changes symptom severity or even remission of anxiety disorders as compared with a delayed-start control group. The investigators will use a delayed-start randomized controlled trial in a cohort of individuals with anxiety and insomnia (N=98) to compare the effects of an online therapist-guided cognitive behavioural and circadian therapy for insomnia versus control on overnight emotion regulation and mental health outcomes.
The project will involve at-home assessments and in-lab visits. At-home assessment involves recording sleep and circadian rhythm measures with wearables and daily diaries. Participants will be invited to perform two sleep studies and neuroimaging sessions to investigate the effects of CBCTi on neuroimaging and psychophysiological markers of overnight regulation of emotional distress.
This study is a delayed-start randomized controlled trial comparing the effects of online therapist-guided cognitive behavioural and circadian therapy for insomnia (CBCTi) versus control on emotional regulation and mental health outcomes.
To be enrolled in the study, the participants are required to complete an online prescreening survey followed by a telephone screening interview with further questions and to verbally explain to participants what is required of them in this study. After an interview screening, the participants will receive a finger-pulse oximeter by mail to screen for the presence of obstructive sleep apnoea (3 nights at-home). The device is then returned by pre-paid mail and the recording is analysed to screen for moderate to severe sleep apnoea (oxygen desaturation index ≥ 10). If eligible, the participant will be invited to the Woolcock Institute for a screening visit.
The screening visit starts with a consult with a clinician/physician who performs a medical screening, explains the study, answers questions and addresses concerns, and obtains written informed consent. At the end of the consult, all eligibility criteria have been evaluated and eligible participants are assigned a randomization number i.e., allocated to either the immediate CBCTi-arm or the delayed-start control-arm. The treatment arm consists of an online therapist-guided CBCTi intervention which comprises online sessions to be completed in 8 weeks. Participants in the delayed-start control arm in this study will not receive any active intervention during the first two months but will be offered the same therapist-guided CBCTi program thereafter
During the screening visit, participants will be asked to perform in an audio-visual recording while singing along to "Waltzing Matilda" (karaoke style) and asked to give keywords that relate to at least five negative distressing experiences and an equal number of neutral experiences from the same period. The recording and the keywords will be used to derive the stimuli that are used in the functional MRI tasks (Pre-Post CBCTi). The screening visit is concluded with a demonstration on how to collect data at-home.
Both groups will be asked to perform a week of at-home assessment during 4 timepoints: T0 (baseline), T1 (2 months post-baseline), T2 (4 months post-baseline) and T3 (12 months post-baseline). During the week of at-home assessments, the participants complete questionnaires, keep a sleep diary, and wear an actigraphy-watch, and light and temperature sensor (across 7 days). They are also asked to complete at least four overnight polysomnographic recordings using an EEG headband. At Pre and Post-CBCTi only, they also complete a salivary melatonin collection protocol.
At Pre and Post-CBCTi (i.e., T0 and T1 for immediate group - T1 and T2 for delayed group) , participants are invited to Macquarie University/Woolcock Institute to undergo overnight sleep studies and neuroimaging sessions.
The CBCTi program will be given online via secure platforms and recruitment will primarily be through social media advertisements. The study will be coordinated from the Woolcock Institute of Medical Research, Sydney, Macquarie Park, New South Wales, 2109, Australia.
Exclusion Criteria:
x Sleep or circadian disorder other than insomnia (e.g., hypersomnolence, periodic limb movement disorder, advanced or delayed sleep phase disorder, moderate to severe sleep apnoea disorder based on previous sleep study with an apnea-hypopnea index ≥ 15 and/or finger-pulse oximetry oxygen desaturation index (ODI) ≥ 10).
Immediate 8-weeks online therapist-guided CBCTi including weekly online modules. Guidance is provided via scheduled and ad hoc communications (e.g., email, messaging, telehealth) between the participant and a clinician/physician
Behavioral: Immediate CBCTi
Participants in the delayed-start control group will not receive any active intervention during two months but will be offered the same therapist-guided CBCTi program thereafter.
Behavioral: Delayed CBCTi
This intervention will be immediately accessible to the CBCTi group. The program is composed of weekly online modules that include written information and interactive components such as schematics, images, videos, and questions. The content of the modules follows traditional and validated cognitive-behavioural therapy for insomnia protocols including sleep education, behavioural strategies (e.g., stimulus control, bedtime retraining, sleep hygiene), cognitive restructuration approaches (e.g., thought reappraisal, imagery, mindfulness), and relaxation practices (progressive muscle relaxation and autogenic training). In addition, further content aims to stabilize and amplify circadian rhythmicity through light exposure in the morning, daytime moderate physical activity, and evening time warm baths. Participants complete daily sleep diaries throughout the intervention.
This intervention will be accessible after a waiting period of 2 months (i.e, delayed start). The program is composed of weekly online modules that include written information and interactive components such as schematics, images, videos, and questions. The content of the modules follows traditional and validated cognitive-behavioural therapy for insomnia protocols including sleep education, behavioural strategies (e.g., stimulus control, bedtime retraining, sleep hygiene), cognitive restructuration approaches (e.g., thought reappraisal, imagery, mindfulness), and relaxation practices (progressive muscle relaxation and autogenic training). In addition, further content aims to stabilize and amplify circadian rhythmicity through light exposure in the morning, daytime moderate physical activity, and evening time warm baths. Participants complete daily sleep diaries throughout the intervention.
General Anxiety Disorder-7 (GAD-7) score
Self-report measures of anxiety symptoms and severity. GAD-7 consists of 7 Likert-scale questions with a total score ranging from 0 to 21 (with higher scores indicating more severe anxiety)
Time frame: 2 months, 4 months, 12 months
Anxiety Disorder diagnosis
Clinician-diagnosed anxiety disorder in accordance with the DSM-5-TR using the Mini-International Neuropsychiatric Interview
Time frame: 2 months, 4 months, 12 months
Insomnia Severity Index (ISI) score
Self-report measures of insomnia symptoms and severity. ISI consists of 7 Likert-scale questions with a total score ranging from 0 to 28 (with higher scores indicating more severe insomnia)
Time frame: 2 months, 4 months, 12 months
EEG sleep efficiency (SE - %)
Mean SE derived from at-home sleep recordings (total sleep time/time in bed\*100)
Time frame: 2 months, 4 months, 12 months
EEG total sleep time (TST - minutes)
Mean TST derived from at-home sleep recordings
Time frame: 2 months, 4 months, 12 months
EEG wake duration (minutes)
Mean wake after sleep onset (WASO) derived from at-home sleep recordings
Time frame: 2 months, 4 months, 12 months
EEG sleep onset latency (SOL - minutes)
Mean SOL derived from at-home sleep recordings
Time frame: 2 months, 4 months, 12 months
EEG sleep stages (%)
Mean time spent in sleep stages (per total sleep period) derived from at-home sleep recordings
Time frame: 2 months, 4 months, 12 months
Actigraphy sleep efficiency (%)
Mean SE derived from actigraphy recording (total sleep time/time in bed\*100)
Time frame: 2 months, 4 months, 12 months
Actigraphy total sleep duration (minutes)
Mean TST derived from actigraphy recordings
Time frame: 2 months, 4 months, 12 months
Actigraphy wake duration (minutes)
Mean WASO derived from actigraphy recordings
Time frame: 2 months, 4 months, 12 months
Actigraphy sleep onset latency (minutes)
Mean SOL derived from actigraphy recordings
Time frame: 2 months, 4 months, 12 months
7-days light exposure (lux)
derived from at-home continuous light recording during the day
Time frame: 2 months, 4 months, 12 months
Hour of Dim-Light Melatonin Onset (HDLMO - hour)
derived from at-home collection of saliva samples
Time frame: 2 months
3-days distal-proximal skin-temperature gradients (DPG)
derived from at-home collection of continuous skin temperature (4 locations)
Time frame: 2 months, 4 months, 12 months
Self-reported sleep duration (min)
Mean TST derived from sleep diaries
Time frame: 2 months, 4 months, 12 months
Self-reported wake duration (min)
Mean WASO derived from sleep diaries
Time frame: 2 months, 4 months, 12 months
Self-reported sleep onset latency (min)
Mean SOL derived from sleep diaries
Time frame: 2 months, 4 months, 12 months
Self-reported sleep quality (out of 5)
Mean sleep quality derived from sleep diaries on a scale from 0 to 4 (very poor sleep to very good sleep)
Time frame: 2 months, 4 months, 12 months
Sleep misperception index (SPI - %)
SPI derived from subjective TST and objective TST (Subj/Obj\*100)
Time frame: 2 months, 4 months, 12 months
Sleep electroencephalographic (EEG) spectral power
derived from polysomnographic (PSG) recordings in-lab: absolute and relative spectral power for band frequencies: slow oscillations (0.25-1.25Hz), delta (0.25-4Hz), theta (4.25-8Hz), alpha (8.25-11.75Hz), sigma (12-16Hz), low beta (16.25-19Hz), high beta (19.25-35Hz) for all stages.
Time frame: 2 months
Sleep electroencephalographic (EEG) neuro-oscillatory coupling
derived from PSG recordings in-lab - phase-amplitude coupling measures (modulation index, preferred phase)
Time frame: 2 months
Functional connectivity patterns in resting-state brain networks
measured by network-wise dual-regression independent component analysis (FMRIB FSL) with the whole-brain voxel-wise connectivity strength is the dependent variable
Time frame: 2 months
EEG sleep-related brain oscillations (characteristics)
EEG neurophysiological events derived from PSG recordings in-lab : density, duration, peak frequency, amplitude, number
Time frame: 2 months
Brain activation during tasks using functional magnetic resonance imaging
Whole-brain voxel-wise brain activation maps of the blood-oxygen dependent signal response to emotional stimuli during the Karaoke and Autobiography tasks.
Time frame: 2 months
Plan to share: No — All study team members have access to the dataset. Other Woolcock-affiliated staff may also request access to the non-identifiable dataset, which will be considered by the principal investigator and co-investigators. A copy of the non-identifiable dataset may be requested by academic collaborators not affiliated with the Woolcock through a data request form, which outlines the investigators, aims and hypotheses, data to be included, a statistical analysis plan, ethics approval, and security measures.
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