The Sleep Clinic Outcome and Practice Study

The goal of this clinical trial is to explore the outcome and practice treatment for sleep-wake disturbances in a Sleep Clinic. The main questions it aims to answer are: * What is the practice (timing and duration of treatment components) of sleep-wake disturbance treatment? * What is the treatment effect of sleep-wake disturbance treatment. Participants will receive treatment as usual by consultations with a trained psychiatrist or psychologist and will be asked to fill out self-reporting questionnaires and sleep diaries.

Inclusion Criteria: * Referred to the Sleep Clinic at St. Olavs Hospital for an assessment of a sleep-wake disruption. * Age \>= 18 years. * Willing and able to provide written informed consent. * Meeting the diagnostic criteria for at least one of the following disorders: F51.0 Insomnia disorder or G47.2 Sleep-wake rhythm disorders, considered being either: Delayed sleep-wake phase disorder, Advanced sleep-wake phase disorder, Non-24-hour sleep-wake disorder or Irregular sleep-wake disorder * Desire non-pharmacological sleep treatment Exclusion Criteria: * Individuals working night shifts or that otherwise have external conditions that result in inadequate sleep opportunity, such as caring for an infant or does not have permanent housing etc. * Individuals being blind * Individuals being psychotic * Individuals having epilepsy * Individuals having an ongoing substance abuse