The symptom and function dimensions of the Global Assessment of Functioning (GAF) scale

The objective was to investigate the validity and clinical impact of the symptom and function dimensions of the Global Assessment of Functioning (GAF) in the Diagnostic and Statistical Manual of Mental Disorders (DSM), Fourth Edition. Is there any need for revision with respect to the DSM, Fifth Edition?

The sample comprised 2695 patients consecutively admitted to 14 different treatment units participating in the Norwegian Network of Personality-Focused Treatment Programs from 1998 to 2007.

Convergent and discriminant validity of the symptom and function dimensions of GAF was analyzed by their associations with demographic variables, diagnostic status, and other self-reported variables assessing symptom distress, interpersonal problems, work and social impairment, and quality of life.

The validity of the separate GAF dimensions was confirmed by discriminant and concurrent associations to other relevant clinical measures. However, the traditional GAF measure based on the lower score of either symptom or function level was found to serve well as a global indicator of symptom distress and social dysfunction. A substantial difference between the symptom and function score of GAF was found in about 10% of the cases; and when differences were found, functional impairment was most often more severe.

This study confirms the validity of the 2 GAF dimensions. However, substantial differences between these dimensions are rarely occurring. We therefore recommend that the GAF scale be prolonged in the DSM, Fifth Edition, roughly in the same shape as in the DSM, Fourth Edition.