December 7, 2025 — FRQS Impact Story
The work led by Dr. Simon Ducharme was featured in an impact story on the Fonds de recherche du Québec (FRQS) website, highlighting the clinical and societal significance of these studies.
Dr. Ducharme and his team are working to improve the distinction between the earliest signs of a neurodegenerative disease and those of a psychiatric disorder. In his clinical practice at the Douglas Research Centre (McGill University), Dr. Ducharme is regularly faced with situations where he must differentiate a typical psychiatric disorder from frontotemporal neurocognitive disorder, particularly in middle-aged patients. Standard tools — including cognitive assessments and brain imaging — do not always provide clear answers at an early stage.
To address this need, his team focused on neurofilament light chain (NfL), a protein released into the blood when neurons are damaged. The researchers analyzed more than 800 blood samples from the Institut universitaire en santé mentale de Montréal using the ultrasensitive SIMOA technology, comparing NfL levels in patients with psychiatric disorders, healthy individuals, and people with frontotemporal dementia.
The results were clear: NfL levels were significantly higher in dementia patients, allowing a reliable distinction, especially in individuals under 65. Interestingly, slightly elevated NfL levels were also observed in some psychiatric patients, suggesting potential neurodegenerative aspects in certain mental disorders.
These findings have already had a direct clinical impact: NfL blood testing is now available in Québec clinics, providing clinicians with an additional tool to make more informed diagnoses in complex cases.
References :
- Ducharme, S., Dols, A., Laforce, R., Devenney, E., Kumfor, F., van den Stock, J., … Pijnenburg, Y. (2020). Recommendations to distinguish behavioural variant frontotemporal dementia from psychiatric disorders. Brain, 143(6), 1632-1650. https://doi.org/10.1093/brain/awaa018
- Light, V., Jones, S. L., Rahme, E., Rousseau, K., de Boer, S., Vermunt, L., … Ducharme, S. (2024). Clinical accuracy of serum neurofilament light to differentiate frontotemporal dementia from primary psychiatric disorders is age-dependent. American Journal of Geriatric Psychiatry, 32(8), 988-1001. https://doi.org/10.1016/j.jagp.2024.03.008
- Liu, E., Jones, S. L., Light, V., Teunissen, C., Bouzigues, A., Russell, L. L., … Ducharme, S. (2025). Accuracy of blood-based neurofilament light to differentiate genetic frontotemporal dementia from primary psychiatric disorders. Journal of Alzheimer’s Disease, 106(4), 1337-1354. https://doi.org/10.1177/13872877251352103