Want to Improve Patients' Mental Health? Start With Their Sleep

John Watson


March 07, 2018

Insomnia: Symptom or Cause?

Sleep disturbances are part and parcel of mental health issues. Conventional thinking goes that a mind under duress will not suddenly relent at day's end, and sleep will suffer as a result.

In recent years, a more complex relationship between sleep and mental health has been advanced. In this updated picture, sleep dysfunction is not solely a symptom of mental health issues but can also act as their direct cause. Researchers have specifically found a causal relationship between insomnia and paranoia, delusions, hallucinations, and other conditions.[1,2,3] This, in turn, has given clinicians a potentially low-burden, high-impact treatment target: Address patients’ insomnia, improve their symptoms.

The viability of this approach was recently tested in the OASIS trial,[4] a randomized analysis of 3775 students at universities in the United Kingdom who received either digital cognitive behavioral therapy (CBT) or usual care. Participants were then screened to see how improved sleep may improve mental health conditions.

To find out more about the results, Medscape recently spoke with Daniel Freeman, PhD, professor of clinical psychology at the University of Oxford and lead author of OASIS, likely the largest-yet randomized controlled trial of a psychological intervention for a mental health problem.

Establishing a Link

Medscape: How did your study design allow you to establish a possible causal link between sleep disturbances and mental health disorders?

Dr Freeman: When it comes to psychological disorders, sleep problems have been very much the poor relation. For too long, insomnia has been trivialized as merely a symptom or epiphenomenon, languishing way down in the league table of problems to be tackled. But there is emerging evidence that poor sleep may actually be a contributory causal factor in the occurrence of many emotional and psychological difficulties.

We wanted to establish this causal role definitively. And the causal implication of this hypothesis is that if you successfully treat sleep problems, then there should also be improvements in other mental health problems. Further, we expected improvements in sleep to mediate improvements in the other mental health problems.

So we randomly assigned a large group of people with insomnia to either receive the best evidence-based psychological treatment for insomnia or simply to continue without it. Before, during, and after the treatment period, we assessed sleep problems and a wide range of other mental health problems, such as anxiety, depression, and paranoia.

Medscape: What did OASIS discover?

Dr Freeman: The results of this clinical trial are very clear: Dealing with sleep problems leads to multiple other benefits for our mental health.

The sleep treatment led to a large reduction in insomnia and small-to-moderate reductions in a wide range of other mental health difficulties. With treatment, insomnia reduced by almost 50%, paranoia dropped by 25%, and both anxiety and depression lessened by 20%. There was also a 10% increase in happiness levels. And our statistical analysis indicated that it was the changes in sleep that led to the changes in the other difficulties.

Overall, it supports the hypothesis that sleep problems are a contributory causal factor in a range of mental health problems.

Changing Perceptions of Sleep

Medscape: Historically, sleep disturbances have been thought to be a symptom, rather than a cause, of mental health disorders. How has recent evidence changed that notion?

Dr Freeman: We hope that the OASIS trial really gets people thinking about this issue. I think that sleep should be given a much higher priority in the assessment and treatment of mental health problems. All too often it is overlooked, despite it being a real concern for patients.

Typically, the assessment and treatment of sleep problems is an afterthought in the training of mental health professionals. This inattention then gets taken into clinical practice, so that too few patients get their sleep problems taken seriously.

But of course there is a great psychological treatment for insomnia, it has knock-on benefits for other aspects of psychological health, and a good experience with mental health care may make people more willing to try other helpful approaches for other difficulties too.

There is too much stigma around mental health issues but much less so for sleep complaints; it would be great if people presenting with a common complaint get a really positive experience of turning around a psychological difficulty.

An Effective, Practical Intervention

Medscape: What did the digital CBT used in your study entail? Does it allow you to reach people who wouldn't have otherwise participated?

Dr Freeman: Sleep problems don't fully explain the occurrence of other mental health problems. Mental health problems are far more complex than that. That means you need to have a large sample size in the clinical test to detect what may be small improvements in other mental health problems in the wake of sleep treatment.

The best way of getting a very large participant group was to do the study online, using a digital CBT intervention. And we recruited from UK universities, meaning that the participant group was at an age when mental health problems are particularly becoming apparent.

The sleep treatment was provided in six sessions, lasting an average of 20 minutes each. Sessions were unlocked online weekly.

The most important treatment step in overcoming insomnia is to relearn that bed leads to falling asleep. Behavior both during the day and at night-time will make this learning possible. Appropriate exercise during the day is encouraged—helping create tiredness. Daytime naps are cut out if possible, helping to build up sleep pressure. Caffeine, alcohol, or nicotine in the evening are best avoided. How to develop a relaxing evening routine and getting the bedroom right for sleep are outlined. And then bed is kept only for sleep, not for, say, watching television or worrying. People are encouraged only to go to bed when very tired and, if the person is not asleep within about 20 minutes, to get up and do something relaxing for a while.

Our bodies appreciate rhythms, so keeping to a sensible and consistent routine of going to bed and getting out of bed is typically very helpful.

Medscape: Do your findings indicate anything about the viability of this digital CBT intervention?

Dr Freeman: The trial certainly shows the clinical benefits of the digital CBT intervention. It is clear that it leads to large reductions in insomnia. It looks like it is especially helpful when all sessions are completed.

However, it is also clear that uptake of the digital intervention, even among this group of people with insomnia, is not that high. So there is an issue to be solved with digital interventions that do not have any other personal support in making them enjoyable and engaging enough that even more people really use them.

Creating a Sleep OASIS

Medscape: To your knowledge, OASIS is the largest-yet randomized controlled trial of a psychological intervention for a mental health problem. How were you able to marshal such large patient numbers? Are there lessons to be learned for researchers trying to bring a comparable statistical robustness to studies of psychological interventions?

Dr Freeman: It may well be the largest randomized controlled trial to date of any treatment type for a mental health problem!

The opportunity has really arisen from being able to conduct trials purely online. And then as clinical academics, we had access to a large potential participant base from UK universities. Emails were sent to several hundred thousand students in the United Kingdom.

The downsides are that you get a large level of missing data to deal with in the analyses, and you certainly don't know the representativeness of the sample.

Young and Restless

Medscape: Your study population was relatively younger. Was this just a matter of study design, in that they were easier to access in larger numbers, or is there something about this general age group that makes them ideal for this analysis?

Dr Freeman: Both. We wanted access to a large participant pool, and universities provided this. But we also considered university students to be at a really interesting age to research mental health problems. University students are at an age when these problems are typically emerging, so we could see whether treating sleep difficulties could potentially prevent the emergence of other mental health problems.

Medscape: Given the age of the participants, can these results be considered applicable to older adults?

Dr Freeman: It has to be tested, for sure. But I would be surprised if the results do not generalize to other age groups.

I do not think it likely that mental health problems such as depression, anxiety, or paranoia have a fundamentally different connection to sleep across each end of adult life. Of course, sleep problems and other mental health problems appear at different rates and may have a slightly differing weight of causal contributions across the lifespan, but I doubt that the connection between them differs substantially.

Medscape: Are you planning any future research in this area?

Dr Freeman: The main focus of my work in this area has been on showing that disrupted sleep is a factor in the occurrence of problems such as delusions and hallucinations in psychotic disorders. So my team has been conducting treatment trials with patients at high risk for psychosis, with patients newly admitted to psychiatric wards, and with patients with ongoing psychotic experiences. We have worked hard on how psychological treatment is best adapted to these specific problems.

The good news from these clinical trials is that it is clear that one-on-one psychological intervention really can help improve sleep problems in these patient groups. The next major challenge will be getting these types of sleep intervention into treatment services as part of standard care.


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