Background: Insomnia, defined as repeated difficulties getting or staying asleep, is common in the general population.
Such sleep difficulties are a problem in their own right, but increasingly it is being recognised that they may also be a
contributory factor in the development of a wide range of mental health problems. Our focus is upon the relationship
between insomnia and psychotic experiences, such as paranoia and hallucinations. Psychotic experiences commonly
occur in mild forms in the general population and have been linked to disrupted sleep. These psychotic-like experiences
raise the risk of development of a clinical disorder. Our aim is to reduce insomnia in a large general population group,
and examine the effect on paranoia and hallucinations at the age when mental health problems typically emerge. The
primary hypotheses are that cognitive behaviour therapy (CBT) for insomnia will reduce insomnia and also levels of
paranoia and hallucinations. The theoretical links will be substantiated by a planned mediation analysis. Improvements in
a number of other mental health outcomes are also predicted.