Clinical effectiveness of a group therapy combining cognitive behavioural therapy for insomnia and imagery rehearsal therapy for nightmares in an operational stress injury clinic.

STUDY OBJECTIVES This study evaluated the effectiveness of a group intervention combining cognitive behavioural therapy for insomnia (CBT-I) and imagery rehearsal therapy (IRT) for nightmares, delivered to current and former military and law-enforcement personnel with post-traumatic stress disorder (PTSD) at an outpatient operational stress injury clinic. This study further investigated the interrelationships among changes in insomnia, nightmares and PTSD symptoms during treatment.

Methods: Sixty outpatients (78% male, 50.7 ± 7.3 years) attended 10 weekly 2-h sessions of CBT-I/IRT and completed daily sleep diaries as well as pre-/post-intervention questionnaires assessing the severity of insomnia, nightmares, and PTSD, sleep-related beliefs, ruminations, and life satisfaction.

Results: From baseline to post-intervention, significant reductions were observed in insomnia severity, nightmare distress and frequency, PTSD severity, dysfunctional beliefs about sleep, and insomnia-related ruminations, while life satisfaction increased (all p < .05). Sleep-diary indices improved following CBT-I/IRT, including shorter sleep onset latency (t(37) = 5.0, p = ≤.001), longer total sleep time (t(37) = -1.7, p = .049), less wake after sleep onset (t(37) = 1.8, p = .037), and higher sleep efficiency (t(37) = -5.1, p ≤ .001). A positive correlation was identified between the degree of improvements in insomnia severity and nightmare distress (r(46) = .41, p = .004). Improvements in insomnia severity (r(48) = .35, p = .013) and in nightmare distress (r(46) = .36, p = .012) both correlated with improvements in PTSD.

Conclusions: This study supports the real-world effectiveness of CBT-I/IRT for addressing sleep disturbances, trauma-related symptoms, sleep-related cognitions and life satisfaction in people with PTSD. The multidimensional symptom improvements highlight the value of jointly addressing insomnia and nightmares in trauma-exposed populations and support wider implementation of CBT-I/IRT among service members.