The interdependence of posttraumatic stress symptoms in parental dyads during and after their child’s treatment for cancer WikmanAnna LjungmanLisa PingelRonnie HagedoornMariët SandermanRobbert von EssenLouise CernvallMartin 2017 <p><b>Background:</b> Cancer in a child is highly distressing and some parents are at increased risk for developing posttraumatic stress symptoms (PTSS). However, the interdependence of PTSS in parental dyads has rarely been accounted for. The aim was to explore the dyadic relationship of PTSS in parents of children diagnosed with cancer.</p> <p><b>Material and methods:</b> The sample includes 150 parents (75 dyads) of 75 children diagnosed with cancer in Sweden during 2002–2004, with follow-up until one year after end of treatment. Data on PTSS from six assessments were included. The first three assessments were carried out during treatment and the remaining after end of treatment. Actor-partner interdependence models were estimated using a structural equation modeling approach to explore the dyadic relationship of PTSS. Actor effects refer to intra-individual dependency over time, and partner effects refer to inter-individual dependency over time, i.e., how much an individual’s symptom levels are affected by their partner’s symptom levels at the previous assessment.</p> <p><b>Results:</b> Results show both actor and partner effects during the child’s treatment. Only an actor effect remained following end of treatment where level of PTSS at one assessment was associated with the level of PTSS at the subsequent assessment. The association between mothers’ and fathers’ PTSS did not remain after end of treatment.</p> <p><b>Conclusions:</b> Parents appear to react as an interdependent emotional system during the child’s treatment but this effect disappears after end of treatment. Results suggest psychological interventions for parents during the child’s cancer treatment should also be sensitive to and address the influence that distress in one partner may have on the other.</p>