Depression has often been considered a risk factor of dementia. However, apathy has been identified as a more accurate risk factor and potentially an early symptom of dementia in a recent study by the University of Cambridge. Apathy is defined as a reduction in goal-directed behavior and can often look like anhedonia, a symptom of depression in which there is a sudden loss of interest in activities that were previously enjoyable. To add to the potential confusion between depression and apathy, the scales used by clinicians and researchers to assess for depression also include measures for apathy. While there is symptomatic overlap between the two, previous MRI studies have helped experts understand that apathy and depression are not the same, but are independent and complex issues.

 Cambridge researchers explored the differences in and the relationship between   apathy, depression, and dementia in individuals with cerebral small vessel disease (SVD). Two independent groups of individuals with SVD were recruited from the United Kingdom and the Netherlands. Across both groups, researchers discovered that those with higher baseline apathy, as well as those with increasing apathy over time, had a greater risk of dementia. Contrary to previous understandings on this topic, neither baseline depression nor changes in depression levels had any effect on dementia risk. Each participant had varying degrees of severity of their symptoms, which allowed researchers to generalize across a broad spectrum of SVD cases. Age, education, and cognition were all accounted for, and the relationship between dementia and apathy remained. 

Of the 450 participants in the United Kingdom, 20% developed dementia, as did 11% of  participants in the Netherlands cohort. The difference between dementia rates is likely due to the increased severity of the SVD cases included in the UK population. Nonetheless, patients who developed dementia in both cohorts showed higher levels of apathy, but similar levels of depression at baseline. Additionally, researchers found that apathy may be an early symptom of white matter network damage. 

This study helps provide the basis for further research to help experts better understand the complexity of dementia. These discoveries are leading experts closer to new and helpful ways of diagnosing and treating patients with dementia in the future. If you are concerned about experiencing apathy or other signs/symptoms of dementia, consider consulting with your primary care provider or reaching out to a licensed psychologist who is trained in neuropsychological testing for further evaluation.