A pilot service evaluation of cognitive behavioural therapy for insomnia (CBT-I) within an NHS Talking Therapies for Anxiety and Depression service

Insomnia disorder is highly prevalent and frequently co-exists with other mental health conditions. Evidence suggests that targeting insomnia may improve overall mental health. Although the effectiveness of cognitive behavioural therapy for insomnia (CBT-I) is well established, it is rarely offered to patients as a discrete treatment. This study aimed to evaluate the outcomes of CBT-I delivered at Step 2 for reducing symptoms of insomnia, as well as anxiety, depression, and impaired functioning, following its implementation within an NHS Talking Therapies service. We examined routinely collected pre- and post-treatment outcomes from 35 patients (median age 60 years, interquartile range 44–68, 63% female) who received CBT-I. Insomnia severity was assessed during the first and last session using the Insomnia Severity Index, while secondary outcomes, including depression, anxiety, and impaired functioning were completed at each session. Intention-to-treat analyses demonstrated significant improvements in insomnia symptoms from pre- to post-treatment, with a large effect size (d = 0.85). Significant improvements were also observed across all secondary outcomes, with large effect sizes for depression (d = 1.01) and anxiety (d = 0.89), and a medium effect size for functioning (d = 0.58). The complete case analysis yielded larger effect sizes across most outcomes. These findings provide preliminary support for the potential benefits of CBT-I as a primary treatment for symptoms of insomnia, with secondary benefits for anxiety, depression, and functioning in patients presenting with mental health difficulties within an NHS Talking Therapies service. Implications for the service and future service evaluations are discussed.