Social skills deficits are a major area of impairment for children and adolescents with ADHD. The results of the present study aid in the understanding of these deficits, both in line with traditional conceptualizations and through a more unique view of the symptoms by comparing them with PDD risk status. In order to examine these social skills difficulties, we used the Social Problems scale of the CBCL, a broad-based behavioral measure that is commonly administered by both researchers and clinicians. Based on the factor analysis, two latent factors were created from seven of the eight Social Problems items of the CBCL, which we labeled Peer Rejection and Social Immaturity. The Peer Rejection factor captured the behaviors typically descriptive of ADHD children, i.e., being teased, not able to get along with others, and not being liked. The Social Immaturity factor was composed of items that are not what one might typically expect to be prototypical of the ADHD child: clingy, preferring younger children, clumsy, and acting young, which may overlap with the social deficits of PDD.
We found that the ‘PDD-risk’ factor was associated with both the Social Immaturity and the Peer Rejection factors, but to a much larger extent for the former. This suggests that risk for PDD in children with ADHD may lie in a particular subset of behaviors that reflect ‘immature’ behavior It should be noted that none of the ADHD cases included in this analysis had scores above the autism cutoff on the SCQ and only 2 exceeded the PDD cutoff. Those numbers needed to be viewed in light of the exclusionary criteria applied at the time of screening for ADHD in subject recruitment (i.e., autism was an exclusionary criteria) and should not be interpreted to reflect an estimate of the frequency of autism in ADHD. Exclusion of the 2 PDD cases did not affect the results at all so the current findings should be interpreted as reflective of social problems in ADHD children without PDD/autism. The Social Immaturity factor was associated with increased hyperactivity while Peer Rejection was associated with increased aggression. IQ was only associated with Peer Rejection (higher IQ, less rejected).
Consistent with the literature on social skills deficits, the current findings support the relationship of aggressive behavior to social problems in ADHD children. Aggression was a small but significant predictor of Peer Rejection (β = .34) and Social Immaturity (β = .38), indicating that aggression is a valuable area to consider for intervention.
The discovery of a strong relationship between PDD-risk and measures of social difficulties assessed by the CBCL in children with a diagnosis of ADHD opens a new avenue of research. These data support a strong relationship of Social Immaturity as assessed by four CBCL items (clingy, preferring younger children, being clumsy, and acting young) with PDD-risk as assessed by family history interview. A significant (but less strong) association was observed for Peer Rejection. What is the significance of this finding? We think the distinction of two types of social problems in ADHD children – without autism or PDD – reflect important subclinical constructs that may be shared across the two disorders, ADHD and PDD. Building on the findings of Santosh and Mijovic (2004)
, we found not only that children with ADHD exhibit aspects of social deficits that are similar to those experienced by children with PDD, but that children with ADHD who also have a higher risk status for PDD are more likely to display these deficits (i.e., Social Immaturity). As we think of social functioning along a continuum, use of the CBCL items, particularly those reflecting Social Immaturity, may identify a subgroup of ADHD children that share etiological underpinnings with PDD/autism.
It may be useful here to conceptualize certain aspects of PDD as being found along a continuum, as well. It could be that rather than PDD being a specific yes/no category, PDD contains characteristics in the social realm (e.g., social immaturity and peer rejection) that are diagnostic by their quantity versus their quality. By utilizing this framework, it can be seen that these characteristics can also contribute to the deficits displayed in other diagnoses, such as ADHD, as examined here. With respect to treatment, the ability to define specific deficits is much more informative than a diagnostic label alone.
The concept of DAMP (deficits in attention, motor control, and perception) may also be relevant to our findings. DAMP consists of children with a diagnosis of both ADHD and Developmental Control Disorder (DCD) who do not have a learning disability or cerebral palsy and has a 4–8% prevalence rate in the general population (Gillberg, 2003
). Half of all cases of ADHD meet the criteria for DAMP. Moreover, autism is strongly related to severe DAMP, with two-thirds of these individuals meeting criteria for PDD. Studies have indicated that DAMP, versus ADHD or DCD alone, accounts for autistic features in these populations (Gillberg, 2003
). Due to our finding that Social Immaturity, which includes clumsiness, is related to PPD risk, a question emerges as to whether DAMP might better account for the overlap between ADHD and PDD. Unfortunately, our research battery does not assess for developmental coordination difficulties, therefore, future research is needed to answer this question.
Additional research is needed in this area utilizing alternative tools of assessment including genetic, brain imaging methods, and neuropsychological testing to investigate etiological factors that may be shared across diagnostic classifications. We speculate that further research using the Social Immaturity items from the CBCL may help define neurobiological processes of a putative ‘endophenotype’ that may be shared with PDD/autism and useful for genetic investigations. From a clinical standpoint, these four items may identify a subgroup of children within ADHD that are most likely to benefit from social skills programs that prove effective in treatment within the PDD/autism populations, to the extent that the curriculums of these programs match the deficits described here.
Limitations and Future Directions
There are several limitations to the present study. First, the current analyses are based on parent report for the creation of the social factors through the use of the parent-rated CBCL and/or through a family history interview for PDD-risk. Although several of our predictors used alternate methods, it would be important to confirm the findings of the present study through the use of teacher ratings or peer ratings of acceptance, for example, and/or observational ratings of social behavior in naturalistic settings. Second, the current analyses are descriptive and correlational in nature. We do not yet have the biological marker research available to investigate how these social factors may reflect hypothesized shared etiological underpinnings but future research along these lines is planned. Third, these findings are also in need of replication in order to determine the validity of the Peer Rejection, Social Immaturity, and PDD-risk factors. While the internal consistency was adequate in consideration of the small number of items comprising each factor, we would also like to see future research improve upon these psychometrics. Lastly, future research is necessary which includes larger samples of singleton ADHD children as well as children with a diagnosis of PDD. The majority of families in the current study are multiplex so findings may not generalize to the more common singleton type of family. Research that includes these clinical samples as well as longitudinal data will inform us on generalizability of the findings as well as whether this association will continue across time and represents a qualitative or quantitative delay in social development among children with ADHD.