How cannabis and cannabis-based drugs harm your brain

How cannabis and cannabis-based drugs harm your brain

  • Long-term use of either cannabis or cannabis-based drugs impairs memory, say researchers.

  • Their study has implications for both recreational users and people who use the drug to combat epilepsy, multiple sclerosis and chronic pain.

  • Researchers studied the effects of the cannabinoid drug WIN 55,212-2 in mice and found that:

  • Long-term exposure impairs learning and memory in the animals

  • Brain imaging studies showed that the drug impairs function in key brain regions involved in learning and memory

  • Long-term 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.

  • Cannabis-based therapies can be very effective at treating the symptoms of chronic diseases such as epilepsy and multiple sclerosis, and dramatically increase the quality of life for people living with these conditions.

  • We need to understand the side effects that these people may experience so that we can develop new interventions to minimise these side effects.


    Francisco M Mouro, Joaquim A Ribeiro, Ana M Sebastião, Neil Dawson. Chronic, intermittent treatment with a cannabinoid receptor agonist impairs recognition memory and brain network functional connectivity. Journal of Neurochemistry, 2018; DOI: 10.1111/jnc.14549