Symptoms of post-traumatic stress in children with cancer: does personality trump health status?

The view of childhood cancer as a traumatic event, and the consequent application of a traumatic stress model towards understanding the experiences of children with cancer, has become a major focus of research in pediatric oncology over the past decade [1]. Many studies have been reported on the incidence of post-traumatic stress disorder (PTSD) or subclinical levels of post-traumatic stress symptoms (PTSS) in children with cancer [2-9] as well as adolescent and young adult survivors of childhood cancer [10-14]. Despite this traumatic stress focus, most studies have not shown a significant elevation in levels of PTSD in the pediatric cancer population. This has led researchers to focus more on subclinical levels of PTSS, suggesting that while full spectrum PTSD may be relatively rare, many children continue to demonstrate concerning levels of post-traumatic symptoms [1,5,15,16]. Yet, even when the focus is limited to PTSS, most studies have failed to show higher levels of PTSS in children with cancer relative to healthy children [2,3,14,17]. Although a number of developmental considerations (e.g., slower and less complete encoding of the traumatic event, lack of knowledge regarding implications of the traumatic event) suggest that children might be less susceptible to PTSD, the available literature actually indicates higher prevalence rates of PTSD in children when compared to adults exposed to comparable trauma [18,19]. It may be that other developmental factors, such as less mature processes of emotional regulation and thus a reduced ability to process and resolve traumatic experiences, serve to increase the likelihood of problematic post-trauma responses [19]. The DSM-IV does not provide distinct diagnostic criteria for children, although it suggests that some symptoms may manifest differently (e.g., repetitive play, in lieu of intrusive thoughts or flashbacks). Nevertheless, in regards to children with cancer, not only do they report levels of PTSS similar to those reported by healthy children, they report lower levels of PTSS than individuals who experienced other stressful events during childhood, such as natural disasters, major accidents, serious physical injury, and death of a parent [18, 20-24]. The low levels of PTSS in children with cancer are even more curious when one considers that the context of the cancer experience involves several factors that could artifactually inflate the endorsement of symptoms consistent with those found on PTSS inventories. For example, with regard to the triad of symptom domains associated with PTSD, re-experiencing/intrusion symptoms (Criteria B) normally defined in terms of thoughts about past events, may be present, but reflect realistic fears about one's current health and invasive treatments, or future oriented fears about the possibility of relapse [25]. Likewise, some of the Criteria C symptoms (numbing/avoidance), particularly those related to diminished recall or distorted encoding (e.g., ‘I have trouble remembering parts of what happened’), might reflect the acute or long-term cognitive effects of treatment. Finally, several of the Criteria D symptoms of increased arousal, which include items involving disturbances in sleep, concentration, and irritability, are also common side effects of cancer therapies. Thus many of the disturbed psychological processes associated with PTSD are confounded with commonly observed effects of cancer and/or its' treatment [1,19]. Moreover, given that cancer and its' treatment is an ongoing process involving repeated stressors, one might expect that some symptoms could be endorsed that reflect acute, rather than post-traumatic stress reactions. From this perspective, the low levels of PTSS typically observed in childhood cancer populations are all the more remarkable. Why are levels of PTSS in the cancer population so low? Certainly, one possible explanation is that the pediatric cancer experience is not as traumatic as many have suggested. A recent study indicates that less than 10% of childhood cancer survivors report a cancer-related trauma [26]. By extension, the tendency to develop PTSD may be more reflective of the adjustment history and personality functioning of the child than it is of the precipitating event, a view put forth by several PTSD theorists [25,27]. From this perspective, one might suspect that the low levels of PTSS are related to differences in personality characteristics between children with cancer and their healthy peers. For instance, a number of studies have found lower levels of trait anxiety in pediatric cancer patients relative to their healthy peers [28-30]. Studies have also shown that within pediatric cancer populations, PTSS is higher in those with high trait anxiety as compared to those with low trait anxiety [1,2,10,31]. The finding of low trait anxiety in children with cancer has been conceptualized more specifically as part of the construct of adaptive style [32,33]. The adaptive style paradigm involves the simultaneous use of two measures; a measure of subjective distress (e.g., trait anxiety) and a measure of defensiveness, typically assessed using social desirability scales [32,33]. Cutoffs are made on these measures to assign respondents into 4 categories, labeled as high anxious, low anxious, defensive high anxious, and repressor. The repressor cell has been the primary focus of study. Repressors tend to present themselves in a favorable light, and thus to look good on most self-report measures. However, research has shown that repressive adaptation is not merely the indication of a response style, but reflects a substantive personality variable [33-35]. Repressors genuinely think of themselves as well-adjusted, self-controlled, and content, and organize their behavior to protect that self-image. A higher incidence of repressive adaptive style has been consistently found in childhood cancer patients compared to healthy children [28-30,36]. The genesis of cancer-control differences in adaptive style is not understood. It may reflect a contingent response to the stress of the cancer diagnosis, and there is some evidence to support this in the context of adult cancer [37,38] However, evidence also suggests that adaptive style reflects a stable, enduring personality variable [33], and in children with cancer, adaptive style measures obtained shortly after diagnosis remain stable across the first year following diagnosis [30]. One study examining PTSS in childhood cancer patients and survivors has shown adaptive style to be a significant determinant of self-reported levels of PTSS [31]. Children identified as low anxious or repressors reported lower levels of PTSS than high anxious children. The authors hypothesized that the generally low levels of PTSS found in children with cancer [2,3,17] might be explained, in part, by adaptive style differences between children with cancer and their healthy peers. However, this study could not directly address the effect of adaptive style on cancer-control differences in PTSS, because the study design did not include a comparison group of healthy children. The current study was designed to extend the work of Phipps et al.[31] by examining the relationship of PTSS to adaptive style in children with cancer and a healthy comparison group. A cross-sectional sample of patients and survivors of pediatric cancer provided self-report measure of PTSS and adaptive style, and nominated acquaintances among their healthy peer group to serve as controls. Based on prior literature, we hypothesized three findings: 1) First we predicted that there would be no differences in levels of PTSS between children with cancer and a healthy peer comparison group. 2) Secondly, we predicted adaptive style would be a significant determinant of PTSS, with children identified as low anxious and repressor reporting lower levels of PTSS than the high anxious participants. 3) Following tautologically from 1 and 2, we predicted that adaptive style would be a much more salient determinant of PTSS outcomes than child health status or health history (cancer vs. control).