This study investigates effects of integrating mental health on staff attitudes in 5 community health centers in Guinea: more specifically, on destigmatizing mental health problems and on adopting patient-centered care approaches. It is based on semi-structured interviews with 27 health workers from health centers having integrated mental health care (Sante Mentale +, with acronym SM+); and, as a comparison group, with 11 health workers working in facilities that do not have integrated mental health (SM-). Attitudinal change among SM+ health workers contrasts sharply with the stigmatizing discourse of SM- health workers. The former, strengthened by their successes in treating mental health patients, have overcome their fears and developed positive attitudes vis-a-vis mental health patients. Furthermore, part of the SM+ workers discovered and adopted a patient-centered approach to care, whereas others remained confined to a biomedical logic. A facilitating factor of change has been the organization of an in-service training program (joint consultations, teamwork and community action) taking into account health workers' emotional needs and providing patient-centered role models. However, this training set-up only functioned optimally in the non-bureaucratic organizational context of a community health center staffed with a stable and qualified team. Our study indicates that, beyond improved access to psychiatric care, integrating mental health in health centers can also reinforce the quality of the therapeutic relationship in general. The contents and modalities of the training program in mental health are crucial; but so is the way the health services are being organized.