iii DIFFERENTIATING BIPOLAR SPECTRUM DISORDERS: THE DIAGNOSTIC UTILITY OF THE BIS/BAS SCALES

Mian-Li Ong: Differentiating Bipolar Spectrum Disorders: The Diagnostic Utility of the BIS/BAS Scales (Under the direction of Eric A. Youngstrom) The present study examined discriminative validities of the Behavioral Inhibition System/Behavioral Approach System (BIS/BAS) scales in differentiating bipolar spectrum disorders (BSDs) from other disorders. Participants were youth recruited from a combination of community mental health center and university medical facility. Receiver Operating Characteristic (ROC) analyses tested the BIS/BAS scales in distinguishing between BSD-positive and BSD-negative youth. We calculated diagnostic likelihood ratios in keeping with recommendations from evidence-based medicine. Binary logistic regressions tested for incremental value in combining subscales. BAS subscales discriminated between participants with BSD-positive and BSD-negative diagnoses, with areas under the curve ranging from .54 to .64. The BIS/BAS scales achieved statistical significance in identifying cases with BSDs, but effect sizes for discriminative comparisons were too small to be clinically useful. Upgrading clinical training to: (a) include prevalence of BSDs and (b) teaching clinicians more evidence based assessment strategies is important to improve assessment and diagnosis of BSDs. iv To Eric and Jen Youngstrom, thank you for your support and continued guidance. To my family, thank you for making me the person I am today. Thank you Yen-Ling Chen and Carisa Ruiz for proofreading. And finally, to Merisa, my dearest: I could not have done this without your unyielding support and love.