Functional remission in schizophrenia: A FROGS-based definition and its convergent validity

Functional remission concerns only one third of schizophrenia patients who achieved symptomatic remission. We previously developed a scale devoted to functional remission, named the FROGS (Functional Remission Of General Schizophrenia). This instrument encompasses three clinically relevant dimensions. The aim of this study is to provide a threshold for functional remission relying on these three dimensions, and to compare its psychometric properties with other scales devoted to functional remission. We tested the characteristics of functional remission according to the FROGS. The FROGS was used in different European countries and compared to other valid scales (GAF, PSP and PSRS) in a sample of 295 schizophrenia patients. The association with different parameters as external validators was assessed, including clinical remission. A comparison of the classifying properties of each scale compared to the others was made. The four instruments were equally influenced by the PANSS score, the clinical remission according Andreassen's criteria, the number of past hospitalizations and the presence of a paid working activity. These findings provide a simple threshold for the FROGS, tightly linked to the definition of functional remission, with a good convergent validity. This instrument might be easily used to facilitate the assessment of functional remission in schizophrenia.