A newly developed instrument called MotDem, co-designed with dementia patients, carers, and clinicians, identifies three robust motivational domains in adults across a broad lifespan sample (ages 18–80): goal-directed behaviour, social reward, and pleasure — with a fourth exploratory satiety factor. The three-domain structure replicated in an independent older cohort (ages 45–80) from a different national context. MotDem showed strong convergence with established apathy and anhedonia measures but only modest overlap with general depressive symptomatology, suggesting it captures motivational constructs that standard depression screening misses.
Motivational decline — particularly apathy and anhedonia — has long been recognized as an early marker of neurodegeneration, including Alzheimer's disease, appearing sometimes years before cognitive symptoms. Yet clinical tools have typically collapsed motivation into a single dimension, obscuring which specific motivational driver is eroding. MotDem's multidimensional approach could meaningfully improve early risk stratification and allow more targeted interventions — for instance, distinguishing someone losing social reward sensitivity from someone losing goal-directed drive, which may implicate different neural circuits and treatment pathways. The instrument's participatory design with dementia-affected individuals strengthens its ecological validity. Limitations include the cross-sectional design, which cannot yet demonstrate predictive validity for neurodegeneration, and cohort geographic scope remains unclear. As a preprint not yet peer-reviewed, the psychometric properties and replication claims require independent validation before clinical adoption. Still, this represents a meaningfully incremental advance in geriatric assessment methodology.
