The goal is to collect pilot data on an adapted version of the Transdiagnostic Sleep and Circadian intervention (TranS-C), referred to as 'Fitted TranS-C'.

Mental illness is often severe, chronic and difficult to treat. The sleep disturbance commonly experienced by individuals with a severe mental illness reduces capacity to function and contributes to key symptoms. This study seeks to collect pilot data on an adapted version of the Transdiagnostic Sleep and Circadian intervention (TranS-C). The adapted version will be referred to as 'Fitted TranS-C' as it is designed to improve the fit to delivery within community mental health centers. 'Fitted' treatments are needed because the context for implementation (community setting) typically differs from the original testing context (university setting) causing a lack of 'fit' between the setting and evidence based treatments.

Inclusion Criteria:

• Can understand treatment in English
• Is not currently at risk for suicide or homicide
• Has not worked the night shift more than 2 nights per week in the past 3 months
• Is not pregnant or nursing
• Has a guaranteed bed to sleep in for the next month, which is not a shelter.

Exclusion Criteria:

• At risk for suicide or homicide
• Has worked the night shift more than 2 nights per week in the past 3 months
• Is pregnant or nursing
• Does not have a guaranteed bed to sleep in for the next month