This article was originally published in March 2023.

What happens to our brain when we smoke marijuana for years?

A study published in the Journal of American Psychiatry titled "Long-term Cannabis Users Show Lower Cognitive Reserves and Smaller Hippocampal Volume in Midlife" warned that the effects of marijuana use could be damaging.

The findings were recently revisited by San Francisco-based addictions psychiatrist, Timmen L. Cermak, M.D., who highlighted the potential dangers of long-term cannabis use, summarizing the research, co-authored by Madeline H. Meier, Ph.D.

First things first, what is the hippocampus? 

Plasticity And Vulnerability 

The hippocampus, a complex brain structure embedded deep into the temporal lobe, plays a key role in learning and memory. Cermak explained how studies on London taxi drivers confirmed its plasticity: the more the drivers memorized streets and alleys in the city, the larger their hippocampus grew. 

On the other hand, the hippocampus is also vulnerable, writes Cermak, referring to studies showing cannabis use leads to making it smaller. In addition, other researchers have pointed to the connection between decreased hippocampal volume and cognitive decline. 

Another recent study, published in the journal Neuropsychopharmacology looked at cannabis …

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