UBC Theses and Dissertations
Separation Anxiety Disorder and Oppositional Defiant Disorder : perceived comorbidity between disorders resulting from ambiguous items and halo effects Hommersen, Paul
Although theoretical arguments would suggest little comorbidity between Separation Anxiety Disorder (SAD) and Oppositional Defiant Disorder (ODD), epidemiological studies find otherwise. I examined whether ambiguous symptoms and negative halo effects contribute to this comorbidity. In Study 1, 72 mothers read scenarios of children displaying either SAD or ODD behaviors. The SAD scenarios included behaviors considered by judges to be pure exemplars of SAD, as well as behaviors considered to be ambiguous representations of the disorder. ODD scenarios also included both pure and ambiguous behaviors. After each scenario, mothers rated the child on the behaviors presented in the scenario, as well as behaviors of the alternate disorder, and somatic symptoms. Mothers endorsed the ambiguous behaviors presented in the scenarios significantly less than the pure behaviors; and rated the ambiguous behaviors of the non-presented disorder significantly more often than the pure behaviors of the non-presented disorder. This suggests that some comorbidity between SAD and ODD may be explained by the presence of ambiguous items representing the two disorders. For the SAD scenarios, mothers also endorsed non-presented somatic symptoms, suggesting a general negative halo bias in maternal ratings of anxious children. Study 2 used a clinical sample of parents (N = 201) and youth (N = 177) and examined whether using only nonambiguous, or pure, items from commonly used rating scales would decrease the degree of relatedness between SAD and ODD symptoms. Pure anxiety and oppositional scales were created from the Child Behavior Checklist (CBCL) and Youth Self-Report (YSR). In general, the relationship between these pure scales was compared to the relationship between the commonly used, empirically-derived and DSM-oriented scales assessing anxiety and oppositionality on the CBCL and YSR. The pure scales were significantly less related than the empirical or DSM-oriented scales. Thus, the relatedness of the disorders was decreased by assessing only pure exemplars. In sum, the results of these studies suggest that the comorbidity of SAD and ODD observed in epidemiological studies may be partially due to the inclusion of ambiguous items on commonly used rating scales. Implications for clinical assessment and theory are discussed.
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