Page 119 - Age of onset of disruptive behavior of residentially treated adolescents -Sjoukje de Boer

start of treatment, practitioners could take these predictors into account to assess whether there is an increased risk of dropout. The finding that individuals with EO disruptive behavior had higher chance at dropout, may indicate that for them the treatment was less effective. In reverse, individuals with EO disruptive behavior who completed treatment reported similar outcome as those with AO disruptive behavior. Although the EO and AO groups were not identical to the LCP and AL groups, this finding seems to contradict the idea (Moffitt et al., 2008; Moffitt et al., 1996) that individuals with LCP antisocial behavior would be less susceptible to treatment.
Usefulness of age of onset in clinical practice
The developmental taxonomy of Moffitt has influenced the DSM IV (and 7 subsequently the DSM 5) classification of conduct disorder, by subdividing the conduct disorder classification into childhood onset versus adolescent onset (before or after
age 10). By incorporating this sub classification in the DSM, it was assumed that the
onset of behavioral problems carries clinical importance. In reverse, the usefulness for clinical practice has up till now not been demonstrated, and has even been questioned by some (e.g., Colins & Vermeiren, 2013; Jambroes et al., 2016).
In the current thesis, some evidence supporting the age of onset classification is presented. The fact that we found fewer differences between the EO and AO groups than we had expected, may partly be due to the severity of the AO group's pathology. After all, the sample examined in the present thesis is a very specific clinical group with complex and severe behavioral problems. Although we knew this beforehand, it nevertheless seemed relevant to examine whether the distinction between EO and AO was important in this complex group.
Although for youth with disruptive behavior specific treatment was shown effective overall (Bennett & Gibbons, 2000; Kazdin, 2016; Kazdin et al., 1994; McCart et al., 2006; Serketich & Dumas, 1996; M. Shaw et al., 2012; Van der Pol et al., 2017), individual differences are substantial. In accordance with the risk-need-responsivity model (see e.g., Andrews & Bonta, 2010), treatment should address the needs of the individuals to whom the treatment is targeted. In this light, it makes sense to differentiate in order to get a better view on individuals who may or may not benefit from a specific treatment. Our findings show that a distinction based on the onset of
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