Study found that mice exposed to the drug for long-term had significant memory impairments and could not discriminate between a familiar and novel object.
Long-term use of cannabis or cannabis-based drugs found to impair memory in both recreational users and people who use the drug to combat epilepsy, multiple sclerosis, and chronic pain. Researchers from Lancaster and Lisbon Universities studied the effects of the cannabinoid drug WIN 55,212-2 in mice. The research was published in the Journal of Neurochemistry in July 2018, and it was conducted as part of the European Commission Horizon 2020 funded SynaNET project. Brain imaging studies showed that the drug impairs function in key brain regions involved in learning and memory. Prolong exposure to the drug impairs the ability of brain regions involved in learning and memory to communicate with each other, suggesting that this underlies the negative effects of the drug on memory.
Professor Ana Sebastiao, lead researcher at the University of Lisbon, said: “Importantly, our work clearly shows that prolonged cannabinoid intake, when not used for medical reasons, does have a negative impact in brain function and memory. It is important to understand that the same medicine may re-establish an equilibrium under certain diseased conditions, such as in epilepsy or MS, but could cause marked imbalances in healthy individuals. “As for all medicines, cannabinoid based therapies have not only beneficial disease-related actions, but also negative side effects. It is for the medical doctor to weight the advantages of the therapy, taking into consideration quality of life and diseases progression, against the potential side effects.”
However, very less studies are conducted on understanding of the potential negative side effects of long-term cannabinoid exposure. Previous study reported that heavy, regular cannabis use increases the risk of developing mental health problems including psychosis and schizophrenia. Since recent past, increasing number of population are using the drug for long-term due to its legalization in several countries, while more potent varieties are available for recreational users.