Evaluating and Validating GBI Mania and Depression Short Forms for Self-Report of Mood Symptoms.

Objective: To evaluate short forms of free self-report mania and depression scales, evaluating their reliability, content coverage, criterion validity, and diagnostic accuracy.Method: Youths age 11 to 18 years seeking outpatient mental health services at either an Academic medical clinic (N = 427) or urban Community mental health center (N = 313), completed the General Behavior Inventory (GBI) and other rating scales. Youths and caregivers completed semi-structured interviews to establish diagnoses and mood symptom severity, with GBI scores masked during diagnosis. Ten- and seven-item short forms, psychometric projections, and observed performance were tested first in the Academic sample and then externally cross-validated in the Community sample.Results: All short forms maintained high reliability (all alphas >.80 across both samples), high correlations with the full-length scales (r.85 to.96), excellent convergent and discriminant validity with mood, behavior, and demographic criteria, and diagnostic accuracy undiminished compared to using the full-length scales. Ten-item scales showed advantages in terms of coverage; the 7 Up showed slightly weaker performance.Conclusions: Present analyses evaluated and externally cross-validated short forms that maintain high reliability and content coverage, and show strong criterion validity and diagnostic accuracy - even when used in an independent sample with very different demographics and referral patterns. The short forms appear useful in clinical applications including initial evaluation, as well as in research settings where they offer an inexpensive quantitative score. Short forms are available in more than two dozen languages. Future work should further evaluate sensitivity to treatment effects and cultural invariance.