The study aims to compare variables associated with the exclusive and joint use of primary and specialized care for mental health reasons by individuals diagnosed with a mental disorder in a Montreal/Canadian catchment area. Data were collected from a random sample (2,443 individuals). Among 406 people, diagnosed with a mental disorder 12 months pre-interview, 212 (52%) reported having used healthcare services. Compared to users of primary care only, people who sought both primary and specialized care presented more mental disorders and lower quality of life. People using only specialized healthcare received significantly less social support than persons using primary care exclusively and lived in neighborhoods with a high proportion of rental housing. Healthcare service provision should favor social networking and enable social cohesion and integration, particularly in neighborhoods with a high proportion of rental housing. Shared care and enhanced collaboration with other public and community-based resources should be encouraged.