Negative Halo Effects in Parent Ratings of ADHD, ODD, and CD

Attention-deficit/hyperactivity disorder (ADHD), Oppositional Defiant Disorder (ODD), and Conduct Disorder (CD) are highly comorbid, with symptoms that share some similarities. The evidence-based diagnostic process for these disorders includes ratings from adults in the child’s life to assess behavior across settings, so it is important to understand how these raters think about potentially overlapping symptoms. Researchers have identified negative halo effects in ratings of ADHD and ODD symptoms, but ratings of CD have not been examined in these prior studies. Thus, the current study extended past research to examine negative halo effects in parent ratings of the predominantly hyperactive-impulsive presentation of ADHD (i.e., ADHD/HI), ODD, and CD. Parent participants read one of four vignettes that portrayed an 11-year-old boy displaying symptoms of ADHD/HI, ODD, CD, or typical development, and then completed a disruptive behavior scale. The general trend we found was that the presence of a relatively more severe disorder (i.e., CD) artificially inflated ratings of - or showed a negative halo effect for - the relatively less severe disorder (i.e., ADHD/HI), but with some nuance as discussed in the paper. These findings explain and validate how important it is that clinicians conduct evidence-based psychological assessments to decrease the chance of misdiagnosis.