Objective: Cancer can be a traumatic experience affecting multidimensional aspects of sleep among patients and caregivers. This study examined the differential associations of cancer-related posttraumatic stress symptoms (PTSS) with various sleep markers in this population.

Methods: Patients newly diagnosed with colorectal cancer ( n = 138, mean age = 56.93 years, 31.88% female, 60.14% Hispanic, 6.53 months after diagnosis) and their sleep-partner caregivers ( n = 138, mean age = 55.32 years, 68.12% female, 57.97% Hispanic) completed questionnaires assessing the four PTSS clusters (intrusion, avoidance, alterations in arousal and reactivity, negative alterations in cognitions and mood). Participants also completed daily sleep diaries for 14 consecutive days, from which sleep onset latency (SOL), wake after sleep onset (WASO), and sleep duration were derived.

Results: Actor-partner interdependence model revealed that caregivers' greater alterations in arousal and reactivity were associated with their own longer SOL ( b = 15.59, p < .001) and their patients' longer sleep duration ( b = 0.61, p = .014), whereas patients' arousal and reactivity were associated with their caregivers' shorter SOL ( b = -8.47, p = .050). Patients' and caregivers' greater negative alterations in cognitions and mood were associated with patients' longer SOL ( b = 9.15, p = .014) and shorter sleep duration ( b = -0.41, p = .050), respectively. Caregivers' greater intrusion was related to their own shorter SOL ( b = -10.14, p = .004).

Conclusions: The four PTSS clusters, particularly arousal and reactivity and negative cognitions and mood, have distinct associations with sleep markers individually and dyadically in patients and caregivers affected by cancer. Investigations of psychosocial and biobehavioral pathways underlying these relations are warranted. Tailored trauma treatments and sleep interventions may improve the well-being of this population.