Sleep disturbances have been consistently reported in HIV+ individuals, and occur early in the course of infection. Among disorders of sleep commonly found in HIV, insomnia is by far the most frequent condition, affecting almost 75% of HIV-infected individuals. Compared to non-infected individuals, HIV+ patients are 17% more likely to develop insomnia. Furthermore, not only is insomnia more frequent in HIV; it is also more severe in HIV+ compared to HIV- individuals. The precise mechanisms underlying the vulnerability of this population to insomnia still remain hypothetical, and might involve neurodegenerative processes related to the infection, associated mood disorders (e.g., depression, anxiety), side effects of antiretroviral medications, and psychosocial factors. Importantly, sleep disorders in HIV have been demonstrated to affect the severity of the infection. For instance, sleep disturbances were shown to mediate the association between psychological distress and immune status (T-cytotoxic/suppressor cell counts). In addition, sleep disruption also affects responses to treatment, as illustrated by a report demonstrating that sleep disturbances mediate the association between medication adherence and self-reported HIV symptom severity. Finally, insomnia in HIV seems to be closely associated with the presence of cognitive disturbances. Indeed, virtually all HIV infected individuals with cognitive impairment present insomnia complaints, and greater sleep disturbances were associated with worse cognitive performance (e.g., executive functions, psychomotor speed) in this population. Therefore, insomnia has been shown to affect symptom severity, treatment adherence and cognition in HIV+ individuals.

Despite this demonstrated importance of sleep for the well-being of HIV patients, there are very few studies of sleep treatment interventions in HIV. Two studies have implemented an educational intervention promoting healthy sleep habits (e.g., healthy diet, reduced caffeine consumption, no exercise before bedtime, regular sleep-wake schedules), consisting of either one single session or 10 weekly sessions, with little or no consistent sleep improvement in this population. This is not surprising given that previous studies showed the very limited efficacy of interventions focusing solely on sleep hygiene in a general chronic insomnia population.

The most effective treatment for chronic insomnia currently consists of a multimodal psychological intervention, called cognitive-behavioral therapy for insomnia (CBT-I). CBT-I improves sleep to the same degree as hypnotic medications in the short term, but, in contrast to hypnotics, shows no side effects and remains effective in the long term, with sustained improvement in sleep and daytime functioning up to 2 years after completion of the therapy. CBT-I has proven effective in patients with primary insomnia (i.e. without associated medical condition), as well as in insomnia comorbid with depression or cancer. However, the efficacy of CBT-I has not been studied in HIV+ individuals with insomnia.

Digital Cognitive-Behavioural Therapy for Insomnia (CBT-I): the Sleepio program

CBT-I is an intervention aimed at breaking the patterns of maladaptive thinking and behavior that serve to maintain insomnia. It includes a range of techniques including a behavioral component (stimulus control, sleep restriction, relaxation) combined with a cognitive (managing sleep related worries, the racing mind and intrusive thoughts) and an educational (sleep hygiene) component. CBT-I is usually dispensed in group sessions, including 5 to 8 patients and a trained therapist. The different components of CBT-I are then covered in 6 to 8 weekly sessions of 60-90 minutes each. While CBT-I has been demonstrated as an efficacious treatment option, the personnel-intensive nature of CBT-I constitutes an important barrier to widespread clinical use.

Web-based (digital) CBT-I has been developed to overcome this barrier. Two randomized controlled trials (RCT) have evaluated separate digital CBT-I (dCBT-I) applications. In a first study, a six-week wait-list controlled trial of self-help dCBT-I was tested via a simple web-based platform delivering CBT-I content. Insomnia improvement was significantly better in the dCBT-I group when compared to wait-list control, at 4 weeks follow-up. In addition, 48 weeks following the intervention, within-subjects improvements in insomnia severity were also observed. The second RCT of CBT-I included a six-week placebo-controlled dCBT-I intervention, using a media rich, interactive application with an online discussion forum for users. This platform, named Sleepio (www.sleepio.com), allowed users to receive weekly, interactive sessions with an online virtual therapist. That RCT showed large effects on sleep efficiency (d=1.00) and insomnia severity (using the Sleep Condition Indicator (SCI) scale, d= .77), relative to the placebo control, at 8 week follow-up. Overall more than 75% of patients responded to the intervention, as defined by the recovery of healthy sleep efficiency levels. In addition, dCBT-I also significantly improved daytime function, including self-reported assessment of concentration and productivity, thereby suggesting a potential benefit of CBT-I for cognitive functions.

The current intervention sub-study will test the Sleepio dCBT-I intervention in people with HIV. Free access will be provided to the Sleepio program. The program will be delivered entirely online, in 6 weekly sessions spread over 6-12 weeks. The CBT-I sessions will be delivered by an animated virtual therapist, "The Prof". At the start of therapy, participants will complete a short questionnaire, which will be used to suggest examples of goals. Participants will be encouraged to complete a daily sleep diary online throughout the entire course, which will be used to provide personalized help. Indeed, all interactions with the virtual therapist will be dynamically driven by information from daily sleep diaries completed by the user, to provide baseline, adherence, performance and progress data; sleep diary information will also be used to tailor sleep restriction schedules as a function of to the patients' usual bedtimes. Within each therapy session, sleep diary data will be reviewed, goals will be reviewed and new targets will be set. The treatment content will be based on CBT for insomnia manuals and includes the following techniques: psycho-education, goal setting, sleep hygiene, sleep restriction, stimulus control, cognitive restructuring, paradoxical intention, mindfulness, positive imagery, relaxation (progressive muscle relaxation \& autogenic training), putting the day to rest, thought stopping. Participants will be encouraged to select an appointment time for the Sleepio session and will be prompted via email if they do not attend. In addition, participants will receive an email reminder each morning to prompt them to fill in their sleep diary and will have access to a moderated online community and an online library of information about sleep throughout the course of the intervention. They will be able to view their online 'case file' which includes four sections: a progress review, a reminder of strategies to try out in between sessions, an agreed sleep schedule and a list of further reading. In addition to the Sleepio program, participants will be asked to complete a short set of questionnaires assessing mood, quality of life, cognitive symptoms and sleep quality via an online link prior at the start and end of the program, and at their next routine (main study) follow-up visit.