Using behavior to catch early signs of brain degeneration

With the ever-increasing rates of neurodegenerative disorders worldwide - and the resulting increases in dementia burden - there is a need for better biomarkers to anticipate neurodegeneration early, before irreversible symptoms set in. Neurodegeneration in disorders such as Alzheimer’s disease causes thinning of numerous cortical areas, including the orbitofrontal cortex, medial frontal cortex, anterior cingulate cortex and insula. However, the best way to measure cortical thickness in the living brain - MRI imaging - is prohibitively expensive, making measurements of cortical structure impractical as a routine diagnostic biomarker for neurodegeneration. One potential alternative is to target the mild behavioral impairment (MBI) that is associated with the early stages of neurodegeneration. While there are numerous ways to assess MBI, one convenient assay is the Mild Behavioral Impairment Checklist (MBI-C). The MBI-C is a simple (34 questions), self-administered test that evaluates changes occurring over six months in several behavioral domains: decreased motivation (apathy), emotional dysregulation (mood/anxiety), lack of impulse control, social inappropriateness and abnormal beliefs or thought content. Previous work has established that the MBI-C can detect behavioral changes associated with neurodegeneration; indeed, MBI-C has been used as an early-stage biomarker for dementia. The paper by Leow et al. (2026), in this issue of Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, addresses this question by examining the relationship between MBI-C scores and cortical thinning in a Southeast Asian cohort in Singapore.