This book is an excellent practical manual presenting a novel modular approach to subclinical and clinical insomnia and circadian rhythm disorders using the Transdiagnostic Sleep and Circadian Rhythm Intervention (TranS-C).

The authors emphasise the health benefits of good sleep and propose TranS-C as a pathway to promote sleep health and cite evidence that treating sleep problems in a range of mental health conditions improves both sleep problems and the comorbid mental and physical health conditions. The authors define sleep health as a multidimensional pattern of sleep and wakefulness adapted to individual, social and environmental demands that promote physical and mental health and well-being. Good sleep health is reflected by subjective satisfaction, appropriate timing, adequate duration, high efficiency and sustained alertness during waking hours.

A major premise is that most research and treatment approaches focus on insomnia; whereas in clinical practice sleep problems are often complex with features of insomnia, circadian misalignment, hypersomnolence and sleep–wake irregularities. However, TranS-C draws on a range of existing evidence-based treatments. The content of the proposed treatment modules will be familiar to sleep clinicians and include cognitive–behavioural therapy for insomnia; behavioural therapy for delayed sleep phase presentations, which includes chronotherapy and timed light exposure; interpersonal social rhythm therapy, which has a focus on irregular sleep–wake schedules, e.g. during periods of unemployment; imagery rehearsal therapy for nightmares; and evidence-based treatments promoting adherence to continuous positive airway pressure (CPAP) treatment. Motivational interviewing is used throughout.

The sleep-health framework underlies and guides TranS-C. This approach incorporates the medical model of identifying and treating specific sleep disorders but also incorporates a health-promotion perspective, which emphasises the universal attributes of sleep that can be optimised to promote well-being.

The authors state that the approach is informed by four perspectives on sleep and health: the medical model, which emphasises the treatment of sleep disorders; a World Health Organization approach, which encompasses health and well-being in physical, mental and social domains; integration of mind, body and spirit as incorporated into wellness and role-performance models; as well as models that incorporate the importance of being able to adapt to challenges in the physical and social environment.

The sleep-health framework encourages clinicians to work towards improving sleep health along the following six dimensions: regularity of sleep, subjective satisfaction, alertness during waking hours, timing within a 24-hour cycle, sleep efficiency and sleep duration.

TranS-C therapy utilises four cross-cutting modules consisting of case formulation, sleep and circadian education, behaviour change, and motivation and goal setting. These modules are introduced in the first treatment session and addressed in every subsequent session as rolling interventions. There are also four core modules consisting of establishing regular sleep–wake times, improving daytime functioning, correcting unhelpful sleep-related beliefs and maintenance of behaviour change. Optional modules include improving sleep efficiency, reducing time in bed, dealing with delayed or advanced sleep phase, reducing sleep-related worry and vigilance, promoting compliance with CPAP, negotiating sleep in complicated environments and reducing nightmares. Therapy sessions last 50 minutes and four to ten sessions are typically sufficient, depending on the complexity of the presentation and number of modules to be delivered.

The evidence base for effectiveness of this modular approach to promoting sleep health is currently limited to several small trials. Although the interventions are empirically derived and drawn from existing evidence-based treatments, there is a need for a large-scale evaluation of the approach by independent research groups comparing the effectiveness and health economics of TranS-C with existing approaches.

This book serves as a manual for delivering TranS-C and it provides comprehensive guidance and exemplars. The appendices provide a very useful range of handouts and other useful resources.

This book is a must for all clinicians interested in the psychological aspects of sleep medicine. It is not only useful for those practicing sleep medicine but also for those working in mental health and managing long-term physical health conditions with comorbid sleep issues.