Page 130 - Age of onset of disruptive behavior of residentially treated adolescents -Sjoukje de Boer

order to investigate an interplay of a large number of variables, large samples are needed, which ask for collaborative efforts of multiple institutes and research groups.
One of the factors that could be considered is the aforementioned LPE subtyping or degree of CU traits (Caldwell, Skeem, Salekin, & Van Rybroek, 2006; Hawes & Dadds, 2005; Houghton et al., 2017), which relates to a dimension of psychopathy (Frick, Bodin, & Barry, 2000). This factor should be considered dimensional, and in combination with other dimensional factors, such as impulsivity. Impulsivity (accompanied by irresponsibility) is another dimension of psychopathy (Frick et al., 2000), and is characteristic for individuals with ADHD. A significant part of the sample we examined was diagnosed with ADHD. By abandoning the dichotomous idea that there is or is not an attention deficit disorder, a dimensional approach could be applied and the degree of impulsivity could be determined and used for sub classification. This fits well with the transformative effort as proposed by the RDoC to implement a neuroscience-based psychiatric classification (Insel et al., 2010). Indeed, research among offender populations already suggested that it is important to differentiate between antisocial individuals with and without high levels of psychopathy, especially since their disruptive behavior may look the same on the outside, while the underlying mechanisms leading to their disruptive behavior may be different (Brazil et al., 2018). This certainly also applies to our target group. Furthermore, it is relevant for clinicians, because findings also suggest that individuals with high levels of psychopathy are unresponsive to certain types of interventions and individuals with disruptive behavior can diverge greatly in the treatment interventions to which they respond best (Brazil et al., 2018).
In the present thesis, a considerable part of the sample dropped out of treatment. Of course, dropout can never be completely prevented, nevertheless it is recommended to make efforts to reduce it. To enable reduction, more knowledge is needed about mechanisms causing dropout. Although we did not find differences between pushouts and withdrawals in the factors we examined, both types of dropout probably differ in underlying mechanisms. In order to prevent the different types of dropout, these mechanisms should be further investigated. Research can provide support in this, as well as in the evaluation of deployed motivational trajectories.
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