We previously developed the Functional Remission Of General Schizophrenia (FROGS) scale demonstrating first, reliable assessment in a cross-sectional study and second, good time-stability. The purpose of the present analysis was to propose a shorter version (mini-FROGS), more compatible with the limited time available in a psychiatric visit, focusing on the functional domains that have higher likelihood of being improved with higher and/or longer symptomatic remission in different cultural backgrounds.

We used multiple regressions to find the most informative items explaining increased length of symptomatic remission, using prospective data from a national observational multicenter survey. Then, the mini-FROGS was used in different European countries to test its between-center reliability, compared to other scales.

Four domains were retained as capturing the maximum of symptomatic remission, namely (1) travel and communication, (2) management of illness and treatment, (3) self-esteem and sense of independence and (4) respect of biological rhythms. First, the mini-FROG was evaluated in 443 French patients with clinical remission and 22 without, and 12/18 months later in 140 patients still in clinical remission and 23 in relapse. In Europe, 295 schizophrenia patients were assessed with the mini-FROGS and other scales devoted to functional remission, allowing comparisons. The mini-FROGS showed good correlations with other scales in different countries and demonstrated good psychometric properties.

These results give evidence that a 4 items-only version of the FROGS scale may be useful to assess important aspects of functional remission, tightly linked to the length of clinical remission.