Rationale Observational studies show that psychiatric patients appreciate attention to R/S in mental health care. Several studies investigated the effect of R/S interventions in psychiatric care, but results are diverse. This might be due to heterogeneity of research populations, interventions and outcome as well as the interaction between patients’ needs and professionals’ ideas. Little is known about the impact of a religiosity gap (RG) between professional and patient. Responsiveness to patient’s needs might be a key factor, possibly by affecting the TA and TC. However patient’s needs and the effect of a RG are scarcely investigated. Objective To find out patients’ needs concerning the integration of R/S in psychiatric care, the relation with a perceived and formal RG and the effect of a RG on TA and TC over time. Methods A quantitative survey study will be set out among psychiatric patients in the Netherlands, both with Christian belief and without specific religious orientation. A baseline measurement and a six month follow-up will be carried out to test patients’ TA and TC over time in relation to the integration of R/S in multidisciplinary psychiatric care. Analysis Using multivariate models, it will be examined to what extent patients needs of R/S integration are correlated with a RG and to what extent a formal and perceived RG predict team-wide TA and TC at follow-up. Deliverables Two, preferably three papers submitted to international journals, chapters in a PhD thesis, presentations in mental health clinics and scientific area, nationally and internationally. Impact If patients’ needs concerning R/S integration in psychiatric care are more clearly known and understood, psychiatric care can more adequately respond to them. The importance thereof will be emphasized by a positive effect on TA and TC. Furthermore, future studies concerning the impact of R/S interventions can be more precisely adapted to patients’ needs.