Concurrent validity of the Global Assessment of Functioning Scale for clients with schizophrenia.

Although the Global Assessment of Functioning (GAF) scale is a widely utilized instrument, little data on construct validity is available about its use with clients having schizophrenia. This study compared point-specific GAF scores with concurrent ratings of symptomatology and social and occupational impairments using the Functional Assessment Rating Scale (Ward & Dow, 1994). A linear multiple regression analysis of empirical data from investigations of clients' global functioning showed that increased work and school-related problems, danger to others, and psychotic symptoms predicted lower GAF scores. In general, GAF scores seem to reflect the construct of global psychological, social, and occupational functioning that the scale was designed to measure.