Group cognitive behavioural therapy for insomnia: impact on psychiatric symptoms and insomnia severity in a psychiatric outpatient setting

Objective Insomnia, even when comorbid with other diagnoses is an independent health issue that warrants treatment. Cognitive behavioural therapy for insomnia (CBT-I) is the recommended first-line treatment. Although the science is clear that CBT-I supports outcomes for those with mental ill health, the routine use of CBT-I in mental health contexts is rare. Implementation research on CBT-I in the psychiatric context is urgently needed. This study evaluated group CBT-I as routinely delivered in a psychiatric hospital service.Methods Adult outpatients (N = 76; Mage = 50.20 years; female = 57; psychiatric comorbidity = 69.74%; using sleep medication = 76%) referred for insomnia treatment attended four sessions of group CBT-I. Standardised questionnaires were administered pre- and post-treatment.Results Intent-to-treat analysis revealed statistically significant and clinically meaningful improvements with large effect sizes in insomnia severity (d = 2.5, r = 0.8), depression (d = 1.4, r = 0.5), anxiety (d = 1.2, r = 0.5) and stress (d = 1.2, r = 0.5) symptoms, quality of life (d = 1.4, r = 0.6), and functional impairment (d = 2.2, r = 0.7). Regression analyses indicated pre-post changes in dysfunctional beliefs about sleep accounted for significant variance in post-treatment insomnia severity.Conclusions Results supported feasibility of implementation and real-world effectiveness of CBT-I in a psychiatric setting. Cognitive models of insomnia, emphasising the role of unhelpful beliefs about sleep in insomnia treatment were supported. Future directions include the dissemination of CBT-Insomnia to improve its uptake in psychiatric care.