Prefrontal cortex and putamen grey matter alterations in cannabis and tobacco users

Abstract

Background: Previous magnetic resonance imaging studies in regular cannabis users report altered grey matter volume (GMV) in brain regions, including the prefrontal cortex (PFC), putamen and hippocampus. However, most studies have tended to recruit recreational users with high levels of cannabis use, and have not controlled for the possible confounding effects of tobacco use. We attempt to address these limitations in the present study. Methods: We acquired volumetric images in sex, age and IQ-matched groups of (1) regular Cannabis users who also smoke Tobacco cigarettes (‘CT’; n = 33), (2) non-cannabis-using Tobacco cigarette smokers (‘T’; n = 19) and (3) non-cannabis/tobacco-using Controls (‘C’; n = 35). GMV in bilateral PFC, putamen and hippocampal regions was compared across groups. We also examined the associations between GMV differences and levels of cannabis and tobacco use, measures of intellectual function, and of depression, anxiety and stress. Results: Relative to controls, both CT and T groups showed lower GMV in the left inferior frontal gyrus, and greater GMV in the putamen. In addition, lower GMV in the right frontal pole in the CT group (but not the T group) was associated with lifetime cannabis use, but not with cigarette use. Conclusions: Regular cannabis users who also smoked tobacco cigarettes showed altered GMV patterns relative to controls. However, a similar pattern of GMV differences was also seen between regular tobacco users that did not use cannabis. Further research is needed to disentangle the effects of cannabis and tobacco use on brain structure.

Neural correlates of the revised reinforcement sensitivity theory: A cross‐sectional structural neuroimaging study in middle‐aged adults

“…(2) A full model, additionally controlled for cardio‐metabolic measures including hypertension (yes/no); diabetes (yes/no); body mass index (BMI, in kg/m 2 ); physical activity (metabolic equivalents (METs)/hr in a week; Fraser et al., 2022); alcohol intake (drinks/week); and ever smoked status (yes/no). In addition to the confounding variables identified in the base model, hypertension and high blood pressure (e.g., Cherbuin et al., 2021; Gutteridge et al., 2022), diabetes and high plasma glucose (e.g., Cherbuin et al., 2012; Gómez‐Apo et al., 2021; Shaw et al., 2017), obesity and BMI (e.g., Gómez‐Apo et al., 2021; Shaw et al., 2018; Woo et al., 2022), physical activity (e.g., Fraser et al., 2022; Johansson et al., 2022), alcohol (e.g., Fritz et al., 2022; Geibprasert et al., 2010), and smoking (e.g., Daniju et al., 2022; Karama et al., 2015) are associated with changes in brain structure and were thus included in analyses. Refer to the Supplement for more detailed information on controlled covariates.…”

Cannabinoids: From the brain to society

“…Daniju et al (2022) examined report on prefrontal cortex and putamen grey matter alterations in cannabis and tobacco users. Regular cannabis users who also used tobacco showed altered grey matter volumes (measured with magnetic resonance imaging) when compared to controls.…”

“…However, for most anxietyrelated out comes, cannabidiol had no reported effect, and these data raise questions about the potential utility of cannabidiol for the clinical treatment of anxiety. Daniju et al (2022) examined report on prefrontal cortex and putamen grey matter alterations in cannabis and tobacco users. Regular cannabis users who also used tobacco showed altered grey matter volumes (measured with magnetic resonance imag ing) when compared to controls.…”