“…The evolving views on legalization of marijuana for recreational use in the USA, Canada, and various European countries has led to a growing interest in the long‐term effects of cannabis use on the integrity of human brain structures, especially in regions rich in cannabionoid CB1 receptors, including prefrontal cortex, hippocampus, amygdala, striatum, and cerebellum. Although there are now many studies using structural MRIs to evaluate the long‐term effects of cannabis use, the results have been inconsistent with early studies showing significant loss of gray and/or white matter (e.g., Battistella et al, ; Churchwell, Lopez‐Larson, & Yurgelun‐Todd, ) whereas more recent studies have failed to confirm this, possibly because of various comorbid factors (e.g., Weiland et al ), although one study of a large sample of users showed a correlation between cannabis use and white matter integrity and subcortical, but not cortical, morphometry (Orr, Paschall, & Banich, ).…”