Brain Changes during Cannabis-Induced Psychosis: Clarifying the Marijuana Medicine/Harm Dichotomy
Pierre Flor-Henry, Yakov Shapiro
Journal of psychiatry and brain science 2018 DOI: 10.20900/jpbs.20180009 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | EEG study with literature review Peer reviewed |
|---|---|
| Measures | spectral electroencephalography (EEG) |
| Topics | Cannabis |
| Citations | 1 |
| Key findings | The authors report that psychotic symptoms following cannabis use appear distinct from schizophrenic and affective psychoses and suggest these symptoms occur as a consequence of a generalized shift to right hemispheric dominance, coupled with abnormal activation sources in the excitatory beta and gamma bands in the left temporo-parietal region and impaired engagement of relevant networks in cognitive and spatial goal-directed tasks. |
Abstract
Marijuana is the most widely consumed recreational drug in the world. In Canada, physicians are experiencing increasing pressure to prescribe medical marijuana, with proposed legalization coming in late 2018. The use of marijuana in the psychiatric population is increasing, and the prescribing process is largely unregulated. In spite of several medicinal indications, chronic marijuana use is associated with serious consequences including early-onset psychosis, addiction, persistent psychosocial dysfunction, and neuropsychological abnormalities.In this paper, we present the first spectral electroencephalography (EEG) study of brain changes during cannabis-induced psychosis coupled with a comprehensive review of the literature on medicinal and recreational marijuana use. The findings suggest that psychotic symptoms following cannabis are distinct from schizophrenic and affective psychoses, and occur as the consequence of a generalized shift to right hemispheric dominance. This is coupled with abnormal activation sources in the excitatory beta and gamma bands in the left temporo-parietal region, with impaired engagement of the relevant networks in both cognitive and spatial goal-directed tasks. Detailed recommendations for public education and prescribing process of medicinal marijuana use are discussed.
Comparable studies
Other narrative reviews on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Causal association between cannabis and psychosis: examination of the evidence | 2004 | Review | |
| Cannabis sativa: A comprehensive ethnopharmacological review of a medicinal plant with a long history. General (historical and pharmacological review) | 2018 | Review | |
| Psychiatric effects of cannabis | 2001 | Review | |
| Beyond THC: The New Generation of Cannabinoid Designer Drugs | 2011 | Review | |
| Cannabidiol, a Cannabis sativa constituent, as an antipsychotic drug | 2006 | Review |
Citations in the library
Cites 8
- The entropic brain: a theory of conscious states informed by neuroimaging research with psychedelic drugs Frontiers in Human Neuroscience 2014
- Brain changes during a shamanic trance: Altered modes of consciousness, hemispheric laterality, and systemic psychobiology Cogent Psychology April 24, 2017
- Altered affective response in marijuana smokers: an FMRI study. Drug and Alcohol Dependence November 1, 2009
- EEG of chronic marijuana users during abstinence: relationship to years of marijuana use, cerebral blood flow and thyroid function. Clinical Neurophysiology February 2008
- Cannabis and psychosis: what is the link? Journal of Psychoactive Drugs June 1, 2007
and 3 more in the library