Strengths and Limitations
ADHD
This series of replicated single-case experiments provides a unique examination of the components of a BPT program for children with ADHD. To our knowledge, this is the first series of replicated single-case experiments in children with ADHD that evaluated components of BPT. However, our results have to be viewed in the light of some limitations.First, to examine changes between different phases, single-case experiments ideally start with a relatively stable baseline phase (Second, the current design did not allow for the examination of the effects of the consequent-based techniques in isolation. Because the consequent-based techniques were introduced subsequent to the antecedent-based techniques, it was not possible to “unlearn” parents the use of the antecedent-based techniques. Therefore, we can only draw conclusions about the added efficacy of the consequent-based techniques.Third, we assessed therapist fidelity but did not examine if parents implemented the techniques correctly at home. Although assessment of parental behaviors may have been difficult considering the long period in which the intervention was provided, the large time-investment and the possible Hawthorne effect (i.e., parents modify their behavior, in response to their knowing of being observed), future studies could include for example audiotaped assessments of the interaction between the parent and the child at home to examine procedural fidelity (Fourth, we did not assess whether parents fully mastered the techniques, as was done in some other behavioral parent training programs (e.g., Fifth, although we aimed to have limited between-case variability (i.e., one therapist, same setting, all children on stimulant medication), there were some differences between the cases (e.g., one parent participating/two parents participating in the training sessions). Future single-case experiments can reduce this between-case variability, by only including families with one or two participating parents.Lastly, it should be noted that we did not collect information about medication adherence systematically. It could be that suboptimal medication adherence was associated with less improvement or even worsening of behavior (