An online treatment for insomnia has reduced anxiety and depression in participants, according to a new study.
An online insomnia treatment program has not only improved sleep for participants but reduced symptoms which could have led to major depression, researchers say.
Using the self-help automated program to prevent depression could be likened to using sun cream to prevent skin cancer, chief investigator Professor Helen Christensen told AAP.
The study by the Black Dog Institute, the Australian National University, University of Sydney and the University of Virginia is published in the journal Lancet Psychiatry.
Insomnia is closely associated with many mental illnesses, as a symptom and a potential trigger, and Cognitive Behaviour Therapy (CBT) can effectively treat and prevent both conditions.
The study involved SHUTi, an online CBT-based insomnia intervention designed by the University of Virginia and commercially available.
The 1149 participants were internet users aged 18-64 with insomnia and depression symptoms, but who did not meet criteria for major depressive order.
They were randomly assigned to receive SHUTi or another online program containing information about general health.
The first group experienced significantly reduced insomnia, anxiety and depression, with these improvements persisting for at least six months.
"This is the first trial in the world to demonstrate that CBT-based insomnia treatment can also have a significant impact on the development of depression," Prof Christensen said.
"Since insomnia treatment is rarely stigmatised, this will remove a significant hurdle for those people who feel uncomfortable seeking help.
"This program had the same level of effects expected of face-to-face treatment but was delivered by automated software, giving us a cost-effective way for us to quickly distribute quality treatment and prevention programs across large geographic areas and to a wide range of users."
The 16-week SHUTi package costs $165, which Prof Christensen said was about the same price charged for a first consultation with a clinical psychologist.