Discussion
anger/irritability, primary psychopathy, anxiety, oppositional defiant, aggressive behavior, oppositional defiant symptoms, primary CU traits, trauma
SECONDARY
The current study tested whether 3- to 7-year-old children with conduct problems and primary or secondary CU traits differentially responded to PCIT-CU. Consistent with hypotheses, we found that children classified as having secondary CU traits (i.e., clinically-significant conduct problems, CU traits, and anxiety) demonstrated a faster rate of change in parent-rated number of conduct problems and aggressive behavior symptoms than children classified as having primary CU traits (i.e., clinically-significant conduct problems and CU traits, and low to average anxiety), and that gains maintained over time for both groups. However, somewhat contrary to hypotheses, while children with secondary CU traits showed a faster rate of change in parent-rated frequency of conduct problems and oppositional defiant symptoms during the active treatment period, these gains deteriorated during the follow-up period. In contrast, children with primary CU traits maintained their gains during the follow-up period. Regarding affective outcomes, CU traits improved significantly and, contrary to our hypothesis, the rate of change in CU traits did not differ between primary and secondary variant groups. Unexpectedly, affective empathy did not improve significantly over time for either group. Consistent with our hypothesis, secondary CU traits were associated with a faster rate of improvement in internalizing problems than primary CU traits. Regarding treatment acceptability, there were no group differences in either treatment retention or satisfaction, which were high for both groups. We discuss these five key findings below.Our first key finding is that all children showed improvement in CU traits, with no significant difference between the primary and secondary CU groups in rate of improvement. This finding suggests that PCIT-CU may adequately address the factors maintaining CU traits for both variants, despite their putative etiological differences. PCIT-CU was designed to address three key modifiable risk factors associated with primary CU traits: Low parental warmth, temperamentally-based punishment insensitivity, and Second, we found that some improvements in parent-reported conduct problems deteriorated for children with secondary CU traits. Specifically, deterioration occurred for scales assessing frequency of behaviors characterized by anger/irritability and emotional dysregulation (e.g., “temper tantrums or hot temper”) or non-compliance (“argues a lot”). Within-participant analyses indicated that 84% of treatment-completers in the primary CU group were rated in the normal range for oppositional defiant problems at follow-up, while 73% of completers in the secondary CU group were in the normal range (Supplemental Table An important research implication of this second key finding is that studies investigating the efficacy of treatment adaptations for children with CU-type conduct problems should consider CU variants in the design and analysis of clinical trials. To our knowledge, only four treatment outcome studies have recruited samples exclusively comprised of young children with clinically significant conduct problems and CU traits (Dadds et al., Our third key finding is that PCIT-CU resulted in significant improvement in internalizing problems by follow-up for children with secondary CU traits, despite PCIT-CU not directly targeting this domain. Indeed, within-participant analyses indicated that only 33% off treatment-completers in the secondary CU group were rated in the normal range at post-treatment, but that this percentage increased to 73% at follow-up (Supplemental Table Fourth, we did not find significant improvement in affective empathy following treatment for children with primary or secondary CU traits. This was surprising given improvement in CU traits, of which lack of empathy is a defining characteristic. However, both the reliability and validity of the measure we used to assess empathy have previously received criticism (Kimonis et al., Finally, there were no group differences in either treatment retention or satisfaction, which were generally high, demonstrating good engagement in PCIT-CU by families of children with both primary and secondary CU traits. While this is promising, it cannot be overlooked that the studies from which these data were drawn were conducted under ideal and highly controlled circumstances: Treatment was implemented at a university research clinic in a relatively affluent area of Sydney, Australia according to a comprehensive research protocol by practitioners trained and supervised by the intervention’s developer. Results thus require replication under real world conditions in an effectiveness trial with larger and more ethnically diverse samples of children. This is a critical next step in the dissemination and implementation of evidence-based treatment adaptations for children with CU-type conduct problems in community settings, which has been considerably lacking to date. While the issues of poor availability, accessibility, and acceptability of evidence-based treatment are not unique to children with CU-type conduct problems, we speculate that the relative newness of the ‘with limited prosocial emotions’ specifier for CD and persisting stigma attached to CU traits (Drent et al., Beyond the limitations already identified, which include absence of standardized assessment of historic and current trauma experiences and an affluent, homogenous sample, the current study has five other key limitations. First, our sample size was relatively small and likely underpowered to detect meaningful interaction effects. This study thus warrants replication with a larger and more diverse sample. Second, observed and teacher-reported changes in behavioral and affective outcomes were not examined, limiting the generalizability of findings across settings and informants. Third, families were only followed up to three months posttreatment, limiting generalizability over time. Fourth, we did not assess parent psychopathology, which has been implicated in etiological models of secondary CU traits (Meehan et al., Limitations notwithstanding, this is the first study to demonstrate that primary and secondary variants of young children with elevated CU traits may have different treatment needs. In a resounding challenge to Karpman’s assertion that primary psychopathy is not amenable to change, our findings showed that children with primary CU traits received significant and sustained benefit from an early intervention program tailored to address their unique needs. In contrast, interventions for children with secondary CU-type conduct problems may require further refinement to produce sustained gains across all outcomes, which should be the focus of future efficacy and effectiveness trials with longer-term follow-up periods. Further research is also required to establish the mechanisms by which interventions like PCIT-CU have their impact, including whether these mechanisms differ by CU variant, which will refine our understanding of key treatment targets needed to maximize change (Fleming, 