Collaborative research with a mutual help organization.
D000328:Adult; D000368:Aged; D003156:Community Mental Health Services / Q000458:organization & administration*; D003625:Data Collection; D005260:Female; D006801:Humans; D007087:Illinois; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012657:Self-Help Groups / Q000458:organization & administration*