Sleep therapy road test awakens new interest

The use of sleep restriction therapy to help treat adults with insomnia is under-recognised – despite encouraging results since it was first introduced in the late 1980s.

The problem, according to Flinders University sleep psychologist Professor Michael Gradisar, is that not enough clinical testing has been done to confirm the functioning and capabilities of people affected by insomnia as they go through the therapy.

And that is why new research at Flinders is important for presenting results on how sleep restriction therapy (SRT) doesn't interfere with a patient's ability to perform such tasks as driving a car.

The results have been published in the Sleep Medicine journal in a paper called "Daytime sleepiness, driving performance, reaction time and inhibitory control during sleep restriction therapy for Chronic Insomnia Disorder," by Flinders University researchers Hannah Whittall, Meg Pillion and Professor Gradisar, director of the Child and Adolescent Sleep Clinic at Flinders University.

"We wanted to clarify all aspects of this, to confirm that what we are doing with SRT is not dangerous," Professor Gradisar says. "What we found is strongly supportive of SRT."

Professor Gradisar's concerns reflect the untapped extent of sleep issues affecting a significant proportion of our society.

An estimated 20% of adults have trouble falling asleep, experience frequent awakenings during the night, and feel tired in the morning.

However, despite this, only 6.9% of the population are diagnosed with chronic insomnia disorder.

The need to keep finding effective sleep improvement treatments is therefore of critical importance, and SRT is an effective treatment component of cognitive-behaviour therapy for insomnia.

"This is why the Flinders team investigated the objective and subjective daytime consequences during the acute phase of SRT for adults diagnosed with Chronic Insomnia Disorder," says Professor Gradisar, from the College of Education, Psychology and Social Work at Flinders University.

While the restriction of sleep can induce excessive daytime sleepiness and reaction times, the trial found that the application of SRT according to recent guidelines (set down by the American Academy of Sleep Medicine in 2017) led to an average decrease in sleep duration of 32 minutes.

Importantly, the trial showed that no significant changes in sleepiness, reaction times or driving were found while insomnia patients underwent two weeks of SRT.

"It was interesting to find out that participants did not have impairments to their driving or reaction times when sleep was reduced by 32 minutes per night," says paper co-author Hannah Whittall.

Professor Gradisar hopes these findings will lead to a greater uptake of SRT by sleep therapists, and he encourages further trials to reinforce greater confidence among sleep therapists to employ SRT.

Another co-author Meg Pillion says: "SRT is easy for clients to learn and therapists to implement, and the benefits of using it could be seen within two weeks."