Disorder-specific and transdiagnostic functional impairments across youth internalizing disorders

Lifetime prevalence rates suggest that up to 32% of youth (aged 13 to 18) meet criteria for an anxiety disorder and up to 14% meet for a mood disorder before the age of 18 (Merikangas et al., 2010). In addition to meeting symptom criteria, the Diagnostic and Statistical Manual of Mental Disorders (DSM-5; American Psychiatric Association, 2013) requires that youth experience significant functional impairments across multiple domains, including, occupational/school, social , family, and role impairment. Despite the inclusion of functional impairment in the diagnostic criteria, the emphasis of most clinical trials designed to demonstrate intervention efficacy focus on symptom reduction. In order to address this need, the current study used a transdiagnostic framework to investigate a 2-step process for how functional impairments might help discriminate between youth diagnoses of generalized anxiety disorder (GAD), social phobia (SP), and depression disorders (DD). Step-1 examined differences between “pure” diagnoses of each disorder. Step-2 explored how comorbidity might affect the relationship between diagnoses and functional impairments. A total of 146 youth (ages 7-17) and their parents participated in the study. Predictor variables of clinical diagnoses were determined by a semi-structured interview and parent self-reports were used to measure outcome variables of functional impairments. Results from the multivariate analysis of variance showed that impairments in social functioning were disorder-specific for DD (F(8,92)=3.18, Pillai’s Trace=.43, p=.003, ηp2=.21) and impairments in school functioning were transdiagnostic for SP and DD (F(8,92)=2.28, Pillai’s Trace=.325, p=.03, ηp2=.16). Results did not indicate any augmentative effects (increased impairment) of comorbidity. The study suggests that functional impairments might provide unique information about differential diagnosis beyond symptoms and symptom severity.M.S.Includes bibliographical referencesby Christopher M. Wyszynsk