Treating young people who suffer from insomnia by using online cognitive behavioural therapy (CBT) could reduce debilitating mental health problems such as anxiety and depression, scientists said on Wednesday.
In a large trial published in The Lancet Psychiatry journal, researchers at Oxford University's Sleep and Circadian Neuroscience Institute also found that successfully treating sleep disruption eased psychotic symptoms such as hallucinations and paranoia.
"Sleep problems are very common in people with mental health disorders, but for too long insomnia has been trivialised as merely a symptom, rather than a cause, of psychological difficulties," said Daniel Freeman, a professor of clinical psychology who led the work.
"This study turns that old idea on its head, showing that insomnia may actually be a contributory cause of mental health problems."
The research involved 3,755 university students from across Britain who were randomised into two groups.
One group had six sessions of online CBT, each lasting about 20 minutes, and delivered via a digital programme called Sleepio. The others had access to standard treatments but no CBT.
Freeman's team monitored participants' mental health with a series of online questionnaires at zero, three, 10 and 22 weeks from the start of treatment.
The researchers found that those who had the CBT sleep treatment reduced their insomnia significantly as well as showing small but sustained reductions in paranoia and hallucinatory experiences.
The CBT also led to improvements in depression, anxiety, nightmares, psychological well-being, and daytime work and home functioning.
Andrew Welchman, head of neuroscience and mental health at the Wellcome Trust health charity which helped fund the research, said the results suggested improving sleep may provide a promising route into early treatment to improve mental health.
Freeman added: "A good night's sleep really can make a difference to people's psychological health. Helping people get better sleep could be an important first step in tackling many psychological and emotional problems."