The association between regular cannabis exposure and alterations of human brain morphology: an updated review of the literature.
Valentina Lorenzetti, Nadia Solowij, Alex Fornito, Dan Ian Lubman, Murat Yücel
Current Pharmaceutical Design 2014 DOI: 10.2174/13816128113199990435 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Systematic review Peer reviewed |
|---|---|
| Population | Regular cannabis users and non-cannabis using controls across human structural neuroimaging studies |
| Topics | Cannabis |
| Key findings | The review indicates that regular cannabis use is associated with alterations in medial temporal, frontal, and cerebellar brain regions, with greater alterations among samples using at higher doses for longer periods. Evidence for an association between brain morphology and cannabis use parameters was mixed, and evidence for an association with psychopathology symptoms or neurocognitive performance was poor. The authors argue that methodological issues, including small sample sizes and heterogeneity across studies, make firm conclusions difficult. |
Abstract
Cannabis is the most widely used illicit drug worldwide, though it is unclear whether its regular use is associated with persistent alterations in brain morphology. This review examines evidence from human structural neuroimaging investigations of regular cannabis users and focuses on achieving three main objectives. These include examining whether the literature to date provides evidence that alteration of brain morphology in regular cannabis users: i) is apparent, compared to non-cannabis using controls; ii) is associated with patterns of cannabis use; and with iii) measures of psychopathology and neurocognitive performance. The published findings indicate that regular cannabis use is associated with alterations in medial temporal, frontal and cerebellar brain regions. Greater brain morphological alterations were evident among samples that used at higher doses for longer periods. However, the evidence for an association between brain morphology and cannabis use parameters was mixed. Further, there is poor evidence for an association between measures of brain morphology and of psychopathology symptoms/neurocognitive performance. Overall, numerous methodological issues characterize the literature to date. These include investigation of small sample sizes, heterogeneity across studies in sample characteristics (e.g., sex, comorbidity) and in employed imaging techniques, as well as the examination of only a limited number of brain regions. These factors make it difficult to draw firm conclusions from the existing findings. Nevertheless, this review supports the notion that regular cannabis use is associated with alterations of brain morphology, and highlights the need to consider particular methodological issues when planning future cannabis research.
Comparable studies
Other systematic reviews and meta-analyses on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Effects of cannabis use on outcomes of psychotic disorders: systematic review People with psychotic disorders, as examined in 13 longitudinal studies | 2008 | Systematic review | |
| The Impact of Cannabis Use on Cognitive Functioning in Patients With Schizophrenia: A Meta-analysis of Existing Findings and New Data in a First-Episode Sample Patients with established schizophrenia (meta-analysis: 572) and patients with... | 2010 | Meta-analysis and cross-sectional observational study | n = 700 |
| Medicinal cannabis for psychiatric disorders: a clinically-focused systematic review | 2020 | Systematic review | |
| Neuroimaging in cannabis use: a systematic review of the literature Cannabis users and controls in neuroimaging studies | 2009 | Systematic review | |
| Human Laboratory Studies on Cannabinoids and Psychosis. Healthy human subjects and individuals with schizophrenia | 2016 | Systematic review |
Citations in the library
Cited by 9
- Verbal Memory Performance and Reduced Cortical Thickness of Brain Regions Along the Uncinate Fasciculus in Young Adult Cannabis Users Cannabis and Cannabinoid Research March 29, 2018
- Cognitive outcomes associated with long-term, regular, recreational cannabis use in adults: A meta-analysis. Experimental and Clinical Psychopharmacology August 1, 2020
- Adolescent cannabis use, cognition, brain health and educational outcomes: A review of the evidence. European Neuropsychopharmacology April 5, 2020
- Does thinner right entorhinal cortex underlie genetic liability to cannabis use? Psychological Medicine December 2018
- Acute and Chronic Effects of Cannabinoids on Human Cognition-A Systematic Review. Biological Psychiatry April 1, 2016
and 4 more in the library
Cites 36
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- Evidence for involvement of the insula in the psychotropic effects of THC in humans: a double-blind, randomized pharmacological MRI study The International Journal of Neuropsychopharmacology April 14, 2011
and 31 more in the library