Health-promoting outdoor environments designed for people living with dementia (PLwD) has proved to be an effective non-pharmacological intervention for treatment of symptoms and improved well-being. However, for individuals with Young-Onset Dementia (YOD), who have particular symptoms and needs, the content and design of these environments are underexplored. This study aimed to explore the needs of individuals with YOD in a garden setting, to generate design-related knowledge for 'dementia-friendly' outdoor environments, while contributing to the field of Evidence-Based Design (EBD). An 8-week long nature-based program was carried out in Alnarp's rehabilitation garden, a specifically developed garden based on research from e.g., landscape architecture, environmental psychology and medical science. The study used a triangulation of qualitative methods including six participants with YOD and a multidisciplinary team of five staff members. Content analysis was used for all gathered data, including 17 semi-structured interviews with participants with YOD and with staff. Data collection and analysis was performed based on the evidence-based Quality Evaluation Tool (QET). The study led to a target group adapted version of the QET for people with YOD containing 20 developed environmental qualities for designers to pursue in therapeutic gardens, including the additional quality of Calmness. A progression was noted, as a result of perceived positive effects during the intervention, indicating possible change and development of the group's needs and preferences in the outdoors.
Keywords: dementia-friendly environment; evidence-based design (EBD); garden; health promoting; nature; outdoor environment; people living with dementia (PLwD); supportive environment; young-onset dementia (YOD).