First, owing to its high lipophilic nature, phytocannabinoids like THC can efficiently cross the BBB and block type I IFN responses, reduce oxidative/ER stress in neurons (CB1R mediated), and potentially inhibit microglial activation (likely CB2R mediated), and in doing so may prevent cognitive decline in not only HIV but also other neurodegenerative diseases like AD, PD and, HD. Here, CNR1 is linked to Alzheimer disease.