Interventions for improving chronic sleep disruption
Report by Lampros Bisdounis
In this seminar, Simon Kyle presented the state of affairs on insomnia research and our group’s scientific endeavours to improve current treatment regimens for sleep problems.
Insomnia is defined as a persistent difficulty to initiate or maintain sleep despite adequate opportunity, that results in some form of day-time impairment.. Around one-third of the general population reports acute insomnia symptoms over a 12-month period, while one in ten people experiences chronic sleep problems, making insomnia the second most common mental disorder and the most common sleep disorder. However, insomnia is not simply the clinical presentation of sleeplessness. It is a disorder associated with excessive worry over the consequences of poor sleep, as well as a general disturbance of arousal.
Diagnostically, insomnia relies on the subjective experience of related symptoms. This is due to a misalignment between subjective and objective experiences of sleep and wakefulness. Sleep is clearly and objectively impaired in insomnia. Nevertheless, patients often report much lower total sleep time than what we observe using laboratory measures. Recent advances have shown that instead of mis-perceiving sleep, some insomnia patients might be sensitive to subtle shifts from sleep to wakefulness that are not reflected in standard polysomnographic measurement. Thus, although insomnia is a disorder of objectively measured sleep, it is also a condition not fully appreciated by the existing gold standards of sleep-wake measurements.
Insomnia was traditionally viewed as simply a consequence of the comorbid diagnosis, given that sleep problems are characteristic of the majority of major psychiatric disorders. However, our current understanding is that sleep is also involved in the onset and/or maintenance of psychopathology. In studies using concurrent symptom and rest-activity monitoring, it was evident that sleep disruption is associated with suicidal thoughts, and increased severity of psychotic symptoms the following day. Most importantly, the pathway from sleep to next-day symptoms was stronger than the pathway from day to night.
The prescription of hypnotics is the most common clinical response to insomnia, despite their limited long-lasting effectiveness and despite cognitive behavioural therapy for insomnia (CBT-I) being the recommended first line of treatment. CBT-I is a multi-component treatment involving change in patients’ lifestyle, bedtime behaviours, and dysfunctional beliefs about sleep. Of particular interest to our group is the digital delivery of CBT-I via the Sleepio app. This treatment modality outperforms active placebos and treatment as usual, leading to improvements in both day- and night-time symptoms. Furthermore, to better understand how CBT-I works, we have been investigating the mechanisms of CBT-I, namely sleep restriction therapy (SRT). SRT harnesses the homeostatic sleep drive by reducing and standardising time in bed to increase sleepiness and consolidate sleep. According to our research, SRT effectively increases sleepiness, decreases insomnia severity and leads to enhanced sleep pressure experienced at a more appropriate circadian time.
Future work by our group aims to trial the delivery of SRT by nurses in primary care and assess the benefits of this treatment both for the patient and the healthcare services, refine CBT-I with novel treatment modalities such as bright light therapy and transcranial stimulation, and explore the role of sleep in both mental and physical health conditions.