Introduction
Methods
Search strategy, data sources and study selection
Results
Study | Methods | Design | Participants | Findings |
---|---|---|---|---|
Cahn et al. [7] | sMRI, 1.5 Tesla, 1.2 mm thickness; ROI; VBM | Cross-sectional | First-episode schizophrenia with (N = 27) and without (N = 20) cannabis abuse | No difference in volumes of total white or grey matter, cerebellum and caudate; reduced asymmetry of the lateral ventricles in the SZ-SUD-subgroup |
Szesko et al. [58] | sMRI, 1.5 Tesla, 1.5 mm thickness; ROI | Cross-sectional | First-episode schizophrenia with (N = 20) and without (N = 31) cannabis abuse and healthy controls (N = 56) | Cannabis abuse is associated with less anterior cingulate grey matter; no grey matter volume loss in frontal temporal gyrus or orbitofrontal gyrus |
Bangalore et al. [2] | sMRI, 1.5 Tesla, 1.5 mm thickness; VBM, a priori single mask consisting of hypothesized CB1-rich regions (bilaterally) that included DLPFC, hippocampus, posterior cingulate and cerebellum | Cross-sectional | First-episode schizophrenia with (N = 15) and without (N = 24) abuse and healthy controls (N = 42) | Decrease in grey matter density in the right posterior cingulate cortex (PCC) in SZ-SUD |
Rais et al. [43] | sMRI, 1.5 Tesla, 1.2 mm thickness; VBM | Cross-sectional and Longitudinal | First-episode schizophrenia with (N = 19) and without (N = 32) Cannabis abuse and healthy controls (N = 31) | No morphological difference between the two groups at the beginning of the study at five-year follow-up SZ-SUD shows more pronounced brain volume reduction and larger increase in lateral and third ventricle volumes than SZ-NSUD |
Peters et al. [40] | sMRI, DTI | Cross-sectional | Male ROS (N = 35) with and without a history of cannabis use before the age of 17, matched HC (N = 17) | ROS with cannabis use before the age of 17 showed increased directional coherence in the bilateral uncinate fasciculus, anterior internal capsule and frontal white matter. These abnormalities were absent in FOS without cannabis use before the age of 17 |
Wobrock et al. [66] | sMRI, 1.5 Tesla, 1.0 mm thickness; ROI | Cross-sectional | First-episode schizophrenia (recent-onset psychosis) with (N = 20) and without (N = 21) substance abuse (essentially Cannabis abuse) | No differences in the assessed temporolimbic brain morphology (superior temporal gyrus (STG), amygdala–hippocampus complex and cingulum) between the two subgroups |
Dekker et al. [12] | sMRI, DTI | Cross-sectional | EOS with regular use of cannabis before the age of 15 (N = 10), EOS with regular use of cannabis at the age of 17 years or later (N = 8), EOS who were cannabis naïve (N = 8), HC (N = 10) | Cannabis-naïve EOS showed reduced white matter density and reduced fractional anisotropy in the splenium of the corpus callosum compared with EOS with early-onset cannabis use. In the same brain area, cannabis-naïve EOS showed reduced fractional anisotropy compared with HC |
Rais et al. [44] | sMRI, 1.5 Tesla, 1.2 mm thickness | Cross-sectional, cortical thickness measurement | ROS (N = 51) and HC (N = 31), 5-year follow-up: N = 19 ROS with cannabis abuse, N = 32 without cannabis abuse | Thinning of right supplementary motor cortex, inferior frontal cortex, superior temporal gyrus, angular gyrus, occipital and parietal lobe compared to controls, compared to ROS without cannabis abuse thinning of left DLPFC, left ACC and left occipital lobe demonstrated |
Cohen et al. [11] | sMRI, 1.5 Tesla, 1 mm thickness | Cross-sectional | First-episode schizophrenia with (N = 6) and without (N = 13) Cannabis abuse and healthy controls (N = 19) and healthy cannabis abusers (N = 17) | FES displayed lower total cerebellar grey matter than HC, no difference between FES with and without cannabis abuse in adolescent and young adults |
James et al. [26] | sMRI, DTI, VBM | Cross-sectional | EOS with (N = 16) and without (N = 16) early cannabis abuse and HC (N = 28) | EOS with cannabis abuse showed GM density loss in temporal fusiform gyrus, parahippocampal gyrus, ventral striatum, right middle temporal gyrus, insular cortex, precuneus, right paracingulate gyrus, dorsolateral prefrontal cortex, left postcentral gyrus, lateral occipital cortex and cerebellum. Similar group comparison showed decreased fractional anisotropy (FA) in particular in brain stem, internal capsule, corona radiata, superior and inferior longitudinal fasciculus in EOS with cannabis abuse |
Kumra et al. [29] | sMRI, ROI | Cross-sectional | Adolescents with EOS (N = 35), cannabis abuse (N = 16), EOS + cannabis abuse (N = 13), and healthy controls (HC) (n = 51) | A significant EOS-by-CUD interaction was observed. In the left superior parietal region, both “pure” EOS and “pure” CUD had smaller grey matter volumes that were associated with lower surface area compared with HC. A similar alteration was observed in the comorbid group compared with HC, but there was no additive volumetric deficit found in the comorbid group compared with the separate groups. In the left thalamus, the comorbid group had smaller grey matter volumes compared with the CUD and HC groups |
Study | Methods | Design | Participants | Findings |
---|---|---|---|---|
Habets et al. [22] | sMRI, cortical thickness | Cross-sectional | Patients with schizophrenia (N = 88), healthy siblings at higher than average genetic risk for schizophrenia (N = 98), healthy controls (N = 87) | Patient group displayed reductions in cortical thickness for cannabis exposure, a similar pattern was found in the sibling–control comparison for cannabis |
Welch et al. [61] | sMRI, 1 Tesla, ROI; | Longitudinal | Subjects at high risk for developing schizophrenia exposed (N = 25) and not exposed (N = 32) to cannabis in the intervening period of two years | Cannabis exposure was associated with bilateral thalamic volume loss over time |
Welch et al. [62] | sMRI, 1 Tesla, ROI; | Cross-sectional | Subjects at high risk for developing schizophrenia (N = 147) and healthy controls (N = 36) cannabis abuse | Level of cannabis use correlated significantly and positively with volume increase in the left and right lateral ventricles and third ventricle |
Study | Methods | Design | Participants | Findings |
---|---|---|---|---|
Solowij et al. [52] | sMRI, 3 Tesla, ROI, semi-automated methods | Cross-sectional | Patients with schizophrenia (N = 17, 47 % long-term heavy cannabis users), healthy controls (N = 31, 47 % long-term heavy cannabis users) | Cerebellar white matter volume was reduced in cannabis users with and without schizophrenia compared to healthy non-users, by 29.7 % and 23.9 %, respectively, and by 17.7 % in patients without cannabis use. Healthy cannabis users did not differ in white matter volume from either of the schizophrenia groups. There were no group differences in cerebellar grey matter or total volumes. Total cerebellar volume decreased as a function of duration of cannabis use in the healthy users |
Ho et al. [24] | sMRI, 3 Tesla, slice thickness 3 mm, ROI; CNR1-genotyping; | Cross-sectional | Schizophrenia patients without (N = 183) and with (N = 52) cannabis abuse | Patients with cannabis abuse/dependence had smaller fronto-temporal WM volumes than patients without heavy cannabis use. Significant genotype-by-cannabis use interaction effects on WM volumes |