White Matter Microstructure and Gray Matter Volume in Cannabis-Induced Psychosis and Schizophrenia With Cannabis Use.
Raghav Shah, Abhishek Ghosh, A. Avasthi, C. Ahuja, N. Khandelwal, R. Nehra
The Journal of neuropsychiatry and clinical neurosciences July 25, 2022 DOI: 10.1176/appi.neuropsych.21070172 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Cross-sectional study Peer reviewed |
|---|---|
| Sample size | 60 |
| Population | Three groups of 20 participants each: cannabis-induced psychosis, schizophrenia with cannabis use, and controls without substance use, matched on age, handedness, and education |
| Measures | fractional anisotropy (FA), mean diffusivity, mean kurtosis, voxel-based morphometry |
| Topics | Cannabis |
| Key findings | Participants with schizophrenia and cannabis use showed widespread lower white matter integrity (lower fractional anisotropy) than controls across multiple tracts, while those with cannabis-induced psychosis showed fewer such reductions, lower fractional anisotropy than controls only in the left fornix and right superior fronto-occipital fasciculus, and higher fractional anisotropy than the schizophrenia group in the left corticospinal tract. The cannabis-induced psychosis group also had greater cerebellar gray matter volume than the schizophrenia group and greater inferior frontal gyrus volume than controls. The authors propose that better white matter integrity in some tracts and greater gray matter volumes in key brain areas among those with cannabis-induced psychosis may have prevented transition to schizophrenia. |
Abstract
Objective: This study explored the differences in white matter (WM) microstructural integrity and gray matter (GM) volume between cannabis-induced psychosis (CIP) and schizophrenia with cannabis use (SZC).
Methods: This cross-sectional study with convenience sampling involved three groups of 20 participants each (CIP, SZC, and a control group without substance use), matched on age, handedness, and education. CIP and SZC were diagnosed with the Psychiatric Research Interview for Substance and Mental Disorders. Diffusion tensor and kurtosis imaging were done, and fractional anisotropy (FA), mean diffusivity, and mean kurtosis were estimated. GM volume was measured with voxel-based morphometry.
Results: Group comparisons revealed comparable age at initiation and duration and frequency of cannabis use between participants in the SZC and CIP groups. Participants with SZC had lower FA than controls in the anterior and retrolenticular internal capsule limbs, cingulate gyrus hippocampal formation, fornix, and superior fronto-occipital fasciculus (all p<0.05). Participants with CIP had lower FA than controls in the left fornix and right superior fronto-occipital fasciculus but higher FA than those with SZC in the left corticospinal tract (all p<0.05). On morphometry, participants with CIP had greater cerebellar GM volume than those with SZC and greater inferior frontal gyrus volumes than controls (all p<0.05).
Conclusions: Widespread WM microstructural abnormalities were observed in participants with SZC, and fewer but significant WM disruptions were observed in those with CIP. Better WM integrity in some WM fiber tracts and greater GM volumes in crucial brain areas among those with CIP may have prevented the transition to schizophrenia.