Factors affecting the relationship between adaptive behavior and challenging behaviors in individuals with intellectual disability and co-occurring disorders.

Previous studies have reported an inverse relationship between adaptive behavior and challenging behaviors in individuals with ID. However, it is unclear which characteristics might influence this relationship in individuals with ID and co-occurring conditions. We found a positive correlation between adaptive behavior (Vineland-II) and challenging behaviors (Nisonger Child Behavior Rating Form) in a study of 105 individuals who presented with mostly severe to profound ID and comorbid physical and mental health conditions. These results might be the consequence of the individual participant characteristics. Therefore, participants were separated out into two groups representing the top (n = 24) and bottom quartiles (n = 28) for presence of challenging behaviors. The participants with the highest levels of challenging behaviors had higher levels of adaptive behavior, higher frequency of intermittent explosive/conduct disorder, but lower frequency of epilepsy and cerebral palsy. All participants with the highest levels of challenging behaviors lived in an institutional setting; whereas, those with the lowest level of challenging behaviors lived in either an institutional setting or with their family. In participants with severe/profound ID and multiple co-occurring disorders, a minimum level of adaptive behavior seems to be necessary for the expression of challenging behaviors.