how does cbd affect parkinson’sDecember 15, 2021
Cannabis comes in several forms and can be taken different ways: smoking or vaping dried leaves, swallowing pills or eating or drinking foods (edibles) that contain cannabinoids, putting liquid or drops under the tongue, or applying creams or ointments to your skin (on painful areas, for example). Two U.S. Food and Drug Administration (FDA)-approved prescription cannabis medications also are available for specific conditions, such as epilepsy or cancer- or AIDS-related symptoms.
Here, we offer general information about cannabis and Parkinson’s, tips for talking with your doctor, and more.
Cannabis also could interact with other medications you are taking. While interactions are largely unknown, adding cannabis to a complex regimen of Parkinson’s and other prescription medications could present a risk. It’s important to tell your Parkinson’s doctor what you are taking, so that they can alert you to possible interactions.
Cannabis refers to products from the Cannabis plant, including marijuana.
The amount of THC, CBD, other cannabinoids and other (sometimes unknown) substances varies across products. Sometimes, the levels of these contents may not be known. And even if the product does have a label, studies have shown the label may not fully or accurately represent what’s inside. (There are no federal regulations governing standards of purity or label accuracy. Most states have their own regulations, but these vary.)
In low doses, cannabinoids appear to be relatively well tolerated. But, like all treatments, they have potential side effects: new or worsened nausea; dizziness; weakness; hallucinations (seeing things that aren’t there); mood, behavior or memory/thinking (cognitive) changes; or imbalance. Regular smoking or vaping also could cause lung damage. The potential risks on cognition, mood and motivation (to exercise or participate in other activities, for example) are especially important for people with PD.
If you are considering or taking cannabis, let your doctor know. They may be able to help you weigh the pros and cons, and they’ll have a complete picture of all your treatments (prescription or otherwise) in case there is a change in symptoms or possible drug interaction. They also can direct you to ongoing research studies, if of interest.
What is cannabis?
The main cannabinoid is tetrahydrocannabinol (THC). This can cause the feeling of being “high”—described as happiness, amusement or contentment — that is commonly associated with marijuana. THC may help nausea, pain or muscle spasms, but it also can have negative effects on mood, behavior and thinking. The second most common cannabinoid, cannabidiol (CBD), seems to have less effect on thinking, memory or mood.
In states that have legalized recreational cannabis, you don’t need a license for purchase. However, having a license may decrease costs and provide access to dispensaries that may be more familiar with your condition.
Researchers continue to work on defining safety for cannabis in Parkinson’s. And several studies are looking at possible benefits on specific symptoms. For the most up-to-date clinical trial information, visit Fox Trial Finder .
One of the most common questions people with Parkinson’s ask is, “What about medical marijuana?” Many are curious if and how it might work for different symptoms, and what the research says.
What is medical marijuana?
Through a recent questionnaire in MJFF’s Fox Insight online study , nearly 1,900 people with Parkinson’s shared their experiences with cannabis. In general, most people reported benefits on sleep, anxiety and pain. But some also had side effects and nearly one-third reported not discussing use with their physician. Full results are expected later in 2021.
Marijuana comes from the Cannabis plant, which contains hundreds of different components, including cannabinoids. Cannabinoids bind to receptors throughout the brain and body to influence movement, mood, inflammation and other activities. Many of these receptors are in areas of the brain impacted by Parkinson’s disease (the basal ganglia).
Try to be open, honest and willing to hear what your doctor says. Tell them you are looking at all treatment options and want to learn if and how cannabis might help. And if you are considering or taking specific products, share which. (Bring printed information or a picture of the label.)
Clinical trials have generally had mixed or conflicting results (some positive, some negative). On questionnaires, people often report benefit on pain, sleep, mood, or motor symptoms such as tremor or stiffness. But many also report side effects. This leaves patients, doctors and researchers with insufficient evidence to guide use.
Many doctors and researchers believe the marketing and hype of cannabis products is ahead of the science and evidence. Be wary. Many have watched videos of people with PD using marijuana and seeing all their symptoms disappear within seconds. There also are many internet stories about marijuana as an “all-natural” cure for Parkinson’s (as well as cancer and other conditions). In general, when social media provides a level of endorsement significantly out of proportion to what you hear from your doctor, it is probably too good to be true.
Although clinical diagnosis relies on the presence of cardinal motor features, PD is also associated with numerous non-motor symptoms that can be equally disabling than the motor symptoms or even more so. Drugs that enhance intracerebral dopamine concentrations or stimulate dopamine receptors remain the main treatment for motor symptoms. None of available treatments have proven to be neuroprotective or disease-modifying. Dopaminergic drugs are particularly effective during the early stages of the disease. However, PD invariably progresses, and long-term use of these medications may lead to reduced drug efficacy and the development of complications such as motor fluctuations and dyskinesias.
Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil, Irmandade da Santa Casa de Misericórdia de Porto Alegre (ISCMPA), Porto Alegre, RS, Brazil.
There is a clear need for therapies that target other pharmacological systems. A multimodal approach combining activity on dopaminergic as well as non-dopaminergic system would be very helpful and needs to be explored.
Unlike most of the motor features of PD, many non-motor symptoms do not respond to dopaminergic therapy, and some are indeed aggravated by them, with great impact on patient quality of life. The refractoriness of these symptoms to dopaminergic therapy implicates non-dopaminergic mechanisms. Therefore, current needs in the management of symptomatic patients with PD include dopamine-unresponsive axial motor impairments and non-motor symptoms, such as dementia, depression, anxiety, psychosis, and pain.
Parkinson’s disease (PD) is a common and complex neurological disorder that encompasses a range of clinical, epidemiological, and genetic subtypes. Loss of dopaminergic neurons in the substantia nigra leading to striatal dopamine depletion is the core mechanism underlying the cardinal motor features of PD. Although depletion of dopamine is the most notable neurotransmitter change in PD, other neurochemical changes occur and contribute to PD symptomatology. Many regions of the nervous system outside the basal ganglia are also involved in PD. The underlying molecular pathogenesis involves multiple pathways and mechanisms, such as α-synuclein proteostasis, mitochondrial function, oxidative stress, calcium homeostasis, axonal transport, and neuroinflammation.
In this issue of the Brazilian Journal of Psychiatry , a research group from Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Brazil, addressed animal and human clinical studies involving the use of CBD for PD.1 The authors discussed the biological bases for a potential effect of CBD in this setting, as well as preclinical and clinical studies of CBD in PD. The latter, all conducted by their group, are an open-label study,2 a case series,3 and a randomized controlled trial.4 The open-label pilot study was conducted with six PD patients with psychotic symptoms, lasting at least 3 months before study entry, that could not be controlled by reduction of antiparkinsonian medications.2 Oral CBD doses ranging from 150-400 mg/day, combined with classic antiparkinsonian agents, reduced psychotic symptoms evaluated by different scales (the Brief Psychiatric Rating Scale and the Parkinson Psychosis Questionnaire), with no influence on cognitive and motor signs and no severe side effects. The second study was a case series of four PD patients with REM sleep behavior disorder (RBD).3 All had prompt, substantial, and persistent reductions in he frequency of RBD after CBD treatment. After drug discontinuation, the complex movements of RBD returned with baseline frequency and intensity. The third study was an exploratory double-blind trial of CBD versus placebo.4 Twenty-one PD patients without dementia or comorbid psychiatric conditions were assigned to three groups of seven subjects each who were treated with placebo, CBD 75 mg/day, or CBD 300 mg/day. Participants were assessed with respect to motor and general symptoms score (Unified Parkinson’s Disease Rating Scale [UPDRS]) and well-being and quality of life (Parkinson’s Disease Questionnaire [PDQ-39]). There were no differences across groups in motor score. However, the groups treated with CBD 300 mg/day had significantly different mean total scores in the PDQ-39. The authors point to a possible effect of CBD in improving measures related to quality of life in PD patients without psychiatric comorbidities.
All of these studies showed interesting results, but sample sizes were very small and the duration of follow-up was very short. The Movement Disorder Society Evidence-Based Medicine Committee recommendations for treatments of PD published in 2018 concluded that there was insufficient evidence to support the use of CBD for the treatment of PD at the time.5.
There has been interest in cannabidiol (CBD) as a treatment option for PD because of the identification of multiple potential targets of action in the CNS. CBD is one of the many cannabinoids identified in Cannabis sativa , being the second most abundant constituent after Δ9-tetrahydrocannabinol (THC). Unlike THC, CBD is non-psychoactive, and has been ascribed many potential medical benefits.
It is vital to note that no conclusions can be drawn on the efficacy of CBD in this setting, as larger phase III and conclusive efficacy trials have not been conducted in PD. Double-blind, placebo-controlled, randomized trials with larger samples of patients with PD are needed to elucidate the possible effectiveness and mechanisms involved in the therapeutic potential of CBD in PD. Additionally, studies conducted specifically to evaluate the safety profile of CBD in patients with PD (including long-term safety), possible interactions with antiparkinsonian drugs, and possible side effects, as well as the therapeutic window for motor and non-motor PD symptoms, are also required.