1. Nurse perceptions of SRT, including training and support. 2. Fidelity of intervention delivery by nurses. 3. Whether participants in the control group also receive SRT (ie, contamination). 4. The participant experience of SRT, including reflections on implementing the sleep schedule and perceptions of benefit, as well as any unexpected consequences. 5. Whether level of adherence mediates degree of clinical improvement.6. Views of primary care staff in relation to the implementation of SRT beyond the context of the trial.