BACKGROUND: There is a growing interest in developing tailored non-pharmacological strategies to face patients' needs in dementia. Occupational therapy (OT) may contribute to promote self-empowerment of both patients and caregivers. France has implemented nationwide OT over a short-term period of 3/4 months. The main objective of the MatheoAlz study is to measure the impact of maintaining OT over 4 supplementary months on patients' neuropsychiatric symptoms. METHODS/DESIGN: The MatheoAlz trial (Maintenance of Occupational Therapy in Alzheimer's disease) is a multi-center, pragmatic randomized controlled trial testing maintenance of OT over 4 supplementary months compared to routine OT delivered as recommended. This paper describes the study protocol. MatheoAlz plans to enroll 240 dyads, i.e. dementia patients and caregivers, whose main inclusion criteria are: prescription for routine OT, patients with mild or moderate dementia, living at home, receiving support from an informal caregiver. The study will compare a control group of patients benefiting from 12 to 15 initial sessions of OT over 3/4 months and an intervention group of patients benefiting from these initial sessions plus 8 extra home sessions over 4 supplementary months. The main outcome is the patient's neuropsychiatric symptoms assessed by the Neuropsychiatric Inventory at 8 months. Several clinical outcomes and economic consequences are measured at 4, 8 and 12 months. DISCUSSION: This is the first trial designed to assess the specific impact of the maintaining OT on the patients' neuropsychiatric symptoms burden. The results will inform policymakers on strategies to implement in the near future. TRIAL REGISTRATION: This trial was registered at ClinicalTrials.gov on February 16, 2018, identifier: NCT03435705 .< Réduire