Chronic CBD treatment did not improve behavioral symptoms in a tau-based Alzheimer's mouse model

TAU58/2 transgenic mice showed reduced body weight, reduced anxiety, impaired motor function, and increased freezing in fear conditioning compared to wildtype. Social recognition memory was intact. Chronic CBD (50 mg/kg i.p. for 3+ weeks) did not affect any behavioral measures in transgenic males.

Open-label study of 4-month-old male TAU58/2 transgenic mice and wildtype controls. CBD (50 mg/kg) or vehicle administered intraperitoneally starting 3 weeks before behavioral testing. Assessed anxiety, motor function, fear conditioning, sociability, and social recognition.

While CBD has shown benefits in amyloid-based Alzheimer's mouse models, this study suggests it may not be equally effective in tau-based models, highlighting that Alzheimer's pathology type matters for treatment selection.

Alzheimer's disease involves both amyloid-beta and tau pathology. The failure of CBD in a tau model despite success in amyloid models suggests its neuroprotective mechanisms may be more relevant to amyloid than tau pathology.

Only one dose (50 mg/kg) and one administration route (i.p.) tested. Only male mice at one age (4 months). The mice may have been too young for full tau pathology to develop. No brain tissue analysis to confirm whether CBD reached relevant brain regions or affected tau levels.