Study Questions Causal Link Between Cannabis and Brain Changes
30 October, 2024
Lifetime cannabis use is associated with several changes in brain structure and function in later life, suggested an observational study, but these associations may not be causal, finds a genetic analysis of the same data, published in the open access journal BMJ Mental Health. Some other unidentified factors may explain the differences found, say researchers.
Previously published observational studies have not been able to confirm that cannabis caused the changes seen among regular users and few of these studies have included older people. Neither the duration of cannabis abstinence nor the frequency of cannabis use were strongly associated with any of the observed findings in brain structure and function.
United Kingdom
Endocannabinoid System Changes throughout Life: Implications and Therapeutic Potential for Autism, ADHD and Alzheimer’s Disease
10 June, 2024
The Endocannabinoid System (ECS) has been linked to various physiological and pathological processes, because it plays a neuromodulator role in the central nervous system. In this sense, cannabinoids have been used off-label for neurodevelopmental disorders, such as autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHA), as well as in Alzheimer’s disease (AD), a more prevalent neurodegenerative disease.
This study aimed, through a comprehensive literature review, to arrive at a better understanding of the impact of cannabinoids in the therapeutic treatment of patients with ASD, ADHD and Alzheimer’s disease (AD). Overall, cannabis products rich in CBD displayed a higher therapeutic potential for ASD children, while cannabis products rich in THC have been tested more for AD therapy.
For ADHD, the clinical studies are incipient and inconclusive, but promising. In general, the main limitations of the clinical studies are the lack of standardisation of the cannabis-based products consumed by the participants, a lack of scientific rigor and the small number of participants.
Effect of Cannabis Legalisation in Canada on the Incidence of Psychosis Consultations in Quebec City’s Psychiatric Emergency Services
21 February, 2024
A nationwide study in the United States observed no significant increase in psychosis diagnoses in states where cannabis was legalised. A study in Alberta and Ontario (Canada) observed such an increase but interrupted time series analyses suggested that this was not due to cannabis legalisation as it was the continuation of a trend antedating legalisation.
In Quebec, Canada, an observational study revealed a significant increase in cannabis use following legalisation but no significant difference in consultations for psychosis.
The present study observed no increase in the proportion of ED consultations for a psychotic episode in which evidence for cannabis consumption was obtained before and after legalisation, which is in line with previous studies stating that legalisation had no significative impact on ED’s consultations for psychosis.
Department of Pharmacy and Department of Medicine, State University of Centro Oeste, Guarapuava, Brazil.
Effects of acute cannabis inhalation on reaction time, decision-making, and memory using a tablet-based application
03 February, 2024
Consistent with prior research, study authors concluded that the occasional use group performed slower (reaction time task) or less accurately (memory task) from before to after smoking, as compared to daily use and no-use groups. This is consistent with daily cannabis use resulting in tolerance to the acute effects of cannabis. In the gap acceptance task, the daily use group took longer to complete the task after smoking cannabis, while at the same time increasing their success ratio.
“Taken together, the findings are consistent with acquired tolerance to certain acute ’drug’ effects. The increase in time that the daily use group required to complete the gap acceptance task may nonetheless indicate an acute effect of cannabis among those in the daily use group, who prioritised accuracy over response time. Psychomotor and cognitive assessment batteries, such as the one used in this study, hold promise for providing an objective measure of cannabis impairment”.
Emerging research suggests cannabinoids could play a significant role in protecting against Alzheimer’s disease. Here’s how cannabis might help safeguard your brain health:
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Neuroprotection: Studies indicate that cannabinoids, including cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC), exert a neuroprotective effect. This means they could help protect brain cells from damage, which is crucial in slowing the progression of, or even preventing, Alzheimer’s.
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CBD has been studied for its neuroprotective properties not only in Alzheimer’s but also in epilepsy, suggesting a broad spectrum of brain health benefits. Read more on CBD’s neuroprotective mechanisms in a study from 2020, here
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THC has shown potential in protecting against amyloid beta toxicity, one of the hallmarks of Alzheimer’s disease. Explore THC’s protective effects from a 2023 study here
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Ageing Brain Cells: Research highlights that active ingredients in cannabis can protect ageing brain cells, which is vital, as Alzheimer’s predominantly affects the elderly. Read a study from 2022 on how cannabis protects ageing brain cells here.
Medical cannabis has emerged as a topic of interest as alternatives for managing the challenging symptoms of Alzheimer’s disease are explored. Here’s how it might help manage symptoms:
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Agitation and Behavioural Issues: Evidence suggests that cannabis could be relatively safe and effective for treating behavioural disorders in dementia patients, including agitation, one of the more distressing symptoms for both patients and care givers. Read more about cannabis and agitation in dementia here
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Depression and Mood Disorders: The multi-target action of cannabinoids might offer therapeutic benefits for depression, which often coexists with Alzheimer’s. The interaction with the endocannabinoid system could help in modulating mood and cognitive symptoms. Explore the therapeutic potential here
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General Symptom Relief: Anecdotal evidence and preliminary studies, like the case of one family’s experience, point towards significant relief from symptoms like aggression and agitation with medical cannabis. Watch one family’s story here.
Brain Anatomical Alterations in Young Cannabis Users: Is it All Hype? A Meta-Analysis of Structural Neuroimaging Studies
06 February, 2023
Researchers found no detectable group differences in any of the global brain volumes (intracranium, total brain, total white matter and total grey matter) and regional brain volumes (i.e., hippocampus, amygdala, orbitofrontal cortex and total cerebellum). Age and cannabis use level did not predict (standardised mean) volume group differences. Contrary to evidence in adult samples (or in samples mixing adults and youth), previous single studies in young cannabis users and meta-analyses of brain function in young cannabis users, this early evidence suggests nonsignificant volume differences between young cannabis users and nonusers.
Neuroscience of Addiction and Mental Health Program, Healthy Brain and Mind Research Centre, School of Behavioural and Health Sciences, Faculty of Health Sciences, Australian Catholic University, Fitzroy, Victoria, Australia.
Age- and Sex-Related Cortical Grey Matter Volume Differences in Adolescent Cannabis Users: A Systematic Review and Meta-Analysis of Voxel-Based Morphometry Studies
01 December 2021
Findings suggest that grey matter volumes (GMV) differences between cannabis using and typically developing youth, if present, are subtle, and may vary as a function of age, cumulative cannabis exposure, and sex in young people. Whether age- and sex-related GMV differences are attributable to common predispositional factors, cannabis-induced neuroadaptive changes, or both warrant further investigation.
Johns Hopkins University School of Medicine, Baltimore, Maryland, United States.
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