New research has found that treating insomnia with online cognitive behavioral therapy could in turn help treat mental health problems such as anxiety, depression, and paranoia.

Carried out by researchers at the Sleep and Circadian Neuroscience Institute, University of Oxford, the team set out to try to improve sleep in a group of university students with insomnia to look at sleep's effect on paranoia (excessive mistrust), anxiety, and depression.

The study, which involved 3,755 participants, is thought to be the largest ever randomized controlled trial of a psychological treatment for mental health and the first study large enough to determine the effects of treating insomnia on psychotic experiences.

Participants were randomly split into two groups, with one group receiving online cognitive behavior therapy (CBT) for insomnia while the other group received access to standard treatments.

The six sessions of cognitive-behavioral therapy included behavioral, cognitive and educational components, such as learning to associate bed with sleep, encouraging people to put time aside to reflect on their day before going to bed, and facilitating a pro-sleep environment.

The interactive program also used information from the participants' daily sleep diaries to tailor the advice.

Participants' mental health was also monitored through a series of online questionnaires at 0, 3, 10 and 22 weeks from the start of the treatment.

After analyzing the results the team found that participants who received the CBT sleep treatment showed large reductions in insomnia, as well as small, sustained reductions in paranoia and hallucinatory experiences.

CBT treatment also helped improve other mental health problems including depression, anxiety, nightmares, and psychological well-being, as well as daytime work and home functioning.

"Sleep problems are very common in people with mental health disorders, but for too long insomnia has been trivialized as merely a symptom, rather than a cause, of psychological difficulties. This study turns that old idea on its head, showing that insomnia may actually be a contributory cause of mental health problems," commented the study's lead author Daniel Freeman.

"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," he concluded.

The results can be found published online in The Lancet Psychiatry.