This study compares the two-year clinical and social outcome, the use of services and the direct costs of patients of the South-Verona Community Psychiatric Service who were members of a self-help group, with those who were not. Use of services and costs in the two years before the baseline were compared with those occurring two years after the baseline. Self-help subjects decreased their use of hospital stay as to number of admissions and days in hospital, with a reduction of costs; they were more satisfied as to work/education while non self-help matches presented an increase of unmet needs. Clinical and social outcome showed no significant difference. The findings suggest that consumer participation may possibly enhance the effects of psychiatric treatment on outcome.