Introduction Mental healthcare organisation can either pursue specialisation, that is, distinct clinicians and teams for inpatient and outpatient care or personal continuity of care, that is, the same primary clinician for a patient across the two settings. Little systematic research has compared these approaches. Existing studies subject have serious methodological shortcomings. Yet, costly reorganisations of services have been carried out in different European countries, inconsistently aiming to achieve specialisation or personal continuity of care. More reliable evidence is required on whether specialisation or continuity of care is more effective and cost-effective, and whether this varies for different patient groups and contexts.

Design and methods In a natural experiment, we aim to recruit at least 6000 patients consecutively admitted to inpatient psychiatric care in Belgium, Germany, Italy, Poland, and the UK. In each country, care approaches supporting specialisation and personal continuity coexist. Patients will be followed up at 1 year to compare outcomes, costs and experiences. Inclusion criteria are: 18 years of age or older; clinical diagnosis of psychosis, affective disorder or anxiety/somatisation disorder; sufficient command of the language of the host country; absence of cognitive deterioration and/or organic brain disorders; and capacity to provide informed consent.

Ethics and dissemination Ethical approval was obtained in all countries: (1) England: NRES Committee North East—Newcastle & North Tyneside (ref: 14/NE/1017); (2) Belgium: Comité d'Ethique hospitalo-facultaire des Cliniques St-Luc; (3) Germany: Ethical Board, Technische Universität Dresden; (4) Italy: Comitati Etici per la sperimentazione clinica (CESC) delle provincie di Verona, Rovigo, Vicenza, Treviso, Padova; (5) Poland: Komisja Bioetyczna przy Instytucie Psychiatrii i Neurologii w Warszawie. We will disseminate the findings through scientific publications and a study-specific website. At the end of the study, we will develop recommendations for policy decision-making, and organise national and international workshops with stakeholders.

Trial registration number ISRCTN registry: ISRCTN40256812.