In what scientists are calling “the largest randomized controlled trial of a psychological intervention for a mental health concern,” researchers found that treating insomnia using cognitive-behavioral therapy (CBT), delivered online, appears to improve a variety of mental health concerns. Addressing sleep issues led to improvement in depression, anxiety, and psychotic symptoms such as paranoia and hallucinations.
“This trial indicates the importance of sleep difficulties for mental health in the general population and the need for a reconsideration in clinical services of the priority given to improving sleep,” the researchers write.
The study authors gathered thousands of college students who were experiencing insomnia, and randomized half of them to receive an online CBT treatment called “Sleepio.” They found that not only did participants receiving the therapy improve their sleeping habits, but they were also significantly less likely to experience paranoia, hallucinations, depression, and anxiety.
The research was led by Daniel Freeman, affiliated with the Department of Psychiatry at the University of Oxford, Warneford Hospital, and the Oxford Health National Health Service Trust in the United Kingdom, and the study was published in The Lancet Psychiatry. Freeman and his team assigned 3755 college students–at 26 different universities in the UK–to receive either usual care or online CBT for insomnia.
All of the students were experiencing insomnia. Some of the students exhibited varying levels of depressive, anxious, or psychotic symptoms. The researchers collected data at the beginning of the intervention, at three weeks, at ten weeks (the end of the treatment), and at a 22-week follow-up to determine if results held true for months after the intervention.
There was a high drop-out rate for the online CBT group—only 69% of the students even logged on for a single session, while just 50% received two sessions. By the 6th session, only 18% took part. Even with this drop-out rate, the difference between groups was significant.
The sleep of the group receiving the treatment improved considerably. “After treatment, 54 (62%) of 733 individuals in the treatment group [compared to] 326 (29%) of 1142 individuals in the control group scored outside the clinical cutoff for insomnia.”
The reductions in psychotic experiences, depression, and anxiety, and increases in functioning and psychological well-being were lower, but still significant. The measure for depression (PHQ-9) includes questions regarding sleep, energy, and appetite, so it is unsurprising that these improved. However, the measures of anxiety (GAD-7), paranoia (GPTS), hallucinations (SPEQ), and prodromal psychosis (PQ-16) do not include such questions, so such improvement is further evidence of the impact of sleep on these experiences.
Additionally, those who received CBT for insomnia also showed substantial improvement in measures of daily functioning (WSAS) and psychological well-being (WEMWBS).
Interestingly, the insomnia treatment appeared to increase scores on the Altman scale for measuring mania; however, this could be due to increased energy from improved sleep.
Freeman and his colleagues write that although sleep problems are often viewed as a symptom of mental health concerns, they may, in fact, be a cause of mental health concerns. Sleep problems are associated with almost every mental health diagnosis, including depression, anxiety, and psychosis.
The researchers write that causality can be inferred by manipulating the variable that is theorized to cause the changes while controlling the other variables between groups. That is, the researchers attempted to treat sleep problems in one group, and then compare the experiences of paranoia, hallucinations, depressive symptoms, and anxious symptoms, between the groups. If sleep is a cause of these symptoms, the group that receives successful insomnia treatment should also experience decreases on all those other variables.
After doing this procedure, the researchers write that “Early changes in sleep explain approximately half of the total […] changes in psychotic experiences by the end of treatment” when including paranoia and hallucinations as outcome measures. That is, resolving sleep problems made a very large difference in the psychotic outcomes between the two groups. According to the authors, “These outcomes lend further support to the causal pathway hypothesis proposed in this study.”
The researchers also attempted to examine the possibility of reverse causation. They analyzed the data to determine if changes in paranoia and hallucinations within the first three weeks explained the variance in sleep at the end of the study. They found that paranoia and hallucinations each appeared to explain about 3% of the variance. This small variance suggests that resolving sleep problems has a considerable impact on reducing psychotic experiences, but that the reducing psychotic experiences does not seem to impact sleep substantially.
It is important to note that the study sample was predominantly White and female and that they were university students. It is thus unclear whether the results would generalize to other groups. Additionally, this was not a clinical sample. It is unclear whether this effect would hold true to those with symptoms associated with severe depression, anxiety, or psychotic experiences.
Nonetheless, since sleep problems are associated so strongly with most psychiatric diagnoses, treating those issues with the top recommended method–CBT–is a no-brainer. And if that can help reduce the severity of mental health concerns, possibly eliminating the need for riskier treatments such as medication, so much more the better.
Freeman, D., Sheaves, B., Goodwin, G. M., Yu, L.-M., Nickless, A., Harrison, P. J. . . . Espie, C. A. (2017). The effects of improving sleep on mental health (OASIS): A randomised controlled trial with mediation analysis. The Lancet Psychiatry, 4(10), 749–758. doi: http://dx.doi.org/10.1016/S2215-0366(17)30328-0 (Link)