Clinical effectiveness of a group therapy combining cognitive behavioural therapy for insomnia and imagery rehearsal therapy for nightmares in an operational stress injury clinic.
Behaviour Research and Therapy May 1, 2026 K. Dion, A. Nixon, Rebecca Robillard et al.
A group intervention combining cognitive behavioural therapy for insomnia and imagery rehearsal therapy for nightmares reduced insomnia severity, nightmare distress and frequency, PTSD severity, dysfunctional sleep-related beliefs, and insomnia-related ruminations, while increasing life satisfaction in 60 current and former military and law-enforcement personnel with PTSD. Sleep-diary measures improved, including shorter sleep onset latency, longer total sleep time, less wake after sleep onset, and higher sleep efficiency. Improvements in insomnia severity and nightmare distress each correlated with improvements in PTSD. The findings support the real-world effectiveness of jointly addressing insomnia and nightmares in trauma-exposed populations.