Endocannabinoid signaling is "essential to a number of molecular and cellular activities necessary for learning and memory," according to the researchers. Alzheimer's disease is characterized by a progressive mental decline that begins in middle or late age and is connected to genetic, lifestyle, and environmental factors. It causes memory, language, and cognitive skills to deteriorate. While indica strains of cannabis have traditionally been used to help calm patients and alleviate symptoms of the illness, new research shows that the disease is closely linked to the endocannabinoid system, and with the re-emergence of CBD medicine in Alzheimer's disease, cannabinoid-based treatments are likely to become more common.