What to make of cannabis and cognition in MS: In search of clarity amidst the haze
Anthony Feinstein, Emma Banwell, Bennis Pavisian
Multiple Sclerosis Journal December 1, 2015 DOI: 10.1177/1352458515607652 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Review Peer reviewed |
|---|---|
| Population | People with multiple sclerosis |
| Topics | Cannabis |
| Key findings | The authors argue that cannabis use in people with MS is common and under-researched, and that preliminary evidence suggests smoked cannabis may further compromise information processing speed and memory, with fMRI showing less efficient cerebral activation during tasks. Findings for pharmaceutically manufactured cannabis are equivocal, and the authors call for more research. |
Abstract
Given data showing that cannabis (herbal drug from the Cannabis sativa plant) can impair cognition in healthy subjects, the possibility that it may also do so in people with multiple sclerosis (MS) should be cause for concern. Approximately 20% of people with MS inhale or ingest cannabis for a variety of symptoms, or as a lifestyle choice. In addition, pharmaceutically manufactured cannabis (in capsules or spray) is prescribed most often for pain and spasticity; however, there is a dearth of literature on the cognitive effects of cannabis. Furthermore, methodological limitations introduce a cautionary note when interpreting the data. The evidence, which must therefore be considered preliminary, suggests that smoked cannabis may further compromise information processing speed and memory, with magnetic resonance imaging (fMRI) demonstrating more inefficient patterns of cerebral activation during task performance. The findings related to pharmaceutically manufactured cannabis are equivocal. There is a pressing need for further research to inform clinical opinion, which at present reflects a combination of uncertainty and dogma.
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 4
- Causal association between cannabis and psychosis: examination of the evidence The British Journal of Psychiatry January 30, 2004
- Multiple sclerosis, cannabis, and cognition: A structural MRI study NeuroImage: Clinical April 9, 2015
- Psychopathological and cognitive effects of therapeutic cannabinoids in multiple sclerosis: a double-blind, placebo controlled, crossover study. Clinical Neuropharmacology 2009
- Effects of smoking marijuana on brain perfusion and cognition. Neuropsychopharmacology June 2002