Research findings — medical cannabis
Research on the effects, application and risks of cannabis in medicine
Medical use and care
The medical use of cannabis has developed rapidly in recent years. A growing number of clinical studies and real-world data show that cannabinoid-based medicines can be an effective and well-tolerated treatment option for certain patients — particularly when established treatments are insufficiently effective or involve significant side effects.
The strongest scientific evidence currently exists for:
- Chronic pain, particularly neuropathic pain
- Spasticity in multiple sclerosis
- Nausea and vomiting associated with chemotherapy
- Certain rare, treatment-resistant forms of epilepsy (especially with cannabidiol)
Beyond these, studies and clinical experience increasingly show positive effects for further conditions, including:
- Sleep disorders
- Anxiety and stress symptoms
- Loss of appetite and weight loss
- Chronic accompanying symptoms in long-lasting illnesses
- Distressing symptoms in palliative care situations
In many cases, the focus is not on curing the underlying condition, but rather on:
- Improving quality of life
- Better day-to-day functioning
- Relieving distressing symptoms and more stable symptom control
The tolerability of medical cannabis preparations is generally considered good. Common side effects are fatigue, dizziness or dry mouth and usually occur in a dose-dependent way. With medically supervised titration (“start low, go slow”), unwanted effects can often be reduced.
As with any drug therapy, a careful benefit-risk assessment is required. Particular caution is warranted in patients with severe pre-existing mental conditions or significant cardiovascular disease. Standardised products, adjusted dosing and medical supervision are key to safety and efficacy.
Legal situation in Switzerland
Since August 2022, doctors in Switzerland have been able to prescribe medical cannabis directly. An exceptional authorisation from the Federal Office of Public Health (FOPH) is no longer required.
The main conditions:
- Prescription based on individual medical indication
- Use of standardised, quality-controlled cannabis medicines
- Reporting of certain treatments as part of national accompanying research
- Reimbursement by mandatory health insurance is generally subject to individual cost approval
The legal change has significantly simplified access for patients and at the same time enables better scientific evaluation of treatment experiences in clinical practice.
Access to treatment
In practice, access to medical cannabis takes place via the following steps:
- Medical assessment of symptoms and previous therapies
- Evaluation of whether cannabinoid-based treatment might be useful
- Medical prescription of an appropriate preparation
- Individual clarification of possible reimbursement by health insurance
- Dispensing via pharmacies
Medical cannabis is generally used as a complementary therapy, but for many patients it can deliver a meaningful improvement in symptom control and quality of life.
Findings from current studies
Scientific evidence on the medical use of cannabis is continuously growing. Current studies confirm a nuanced picture: for some areas of use, solid evidence is available, while in many other areas the scientific basis continues to grow.
Areas of use with strong evidence
Epilepsy
Cannabidiol (CBD) remains one of the best-studied cannabinoids. Meta-analyses show a reduction in seizure frequency of around 30–50% for severe, treatment-resistant forms of epilepsy.
Chronic pain
The evidence is strongest for neuropathic pain. Around two thirds of randomised studies report positive effects. The average pain reduction is moderate, but for affected patients it can mean noticeable relief in everyday life.
Multiple sclerosis
Spasticity remains one of the best-evidenced indications. New registry data also show improvements in quality of life and, in some cases, bladder function, over observation periods of up to two years.
Chemotherapy-induced nausea and vomiting
Cannabinoids have a demonstrated antiemetic effect and are used in particular when standard therapies are not sufficiently effective.
Areas of use with moderate evidence
Anxiety disorders and PTSD
Studies show anxiolytic effects of CBD. Observational and registry data report improvements in symptoms, sleep and quality of life, although further controlled studies are needed.
Depressive symptoms
Findings remain mixed. Observational data suggest possible improvements over longer periods, but do not yet allow clear causal conclusions.
Sleep disorders
Many patients report subjective improvements. Initial studies on combinations of THC and CBD show positive effects on sleep quality and time to fall asleep, although results are still inconsistent.
Inflammatory bowel disease
Studies show improvements in symptoms and quality of life, even though a direct anti-inflammatory effect has not so far been consistently demonstrated.
Oncology care
Cannabinoids are increasingly used in a supportive role to relieve pain, anxiety, sleep problems and loss of appetite. Pre-clinical studies also show potential antitumor effects, which are currently being further investigated in clinical research.
Safety — current findings
New studies confirm that the risk profile depends strongly on active-substance content, dosage and patient selection:
- High-potency THC products are linked to an increased risk of psychotic symptoms
- There are indications of possible cardiovascular risks, although the evidence is inconsistent
- High-dose or long-term use can increase the risk of cannabis dependence
- Observational studies suggest that medical cannabis use in chronic-pain patients may be associated with lower opioid use
Overall assessment
The medical use of cannabis is increasingly evolving into an evidence-based treatment option for selected patient groups.
While for some indications a solid scientific basis already exists, evidence in further areas continues to grow. Future research will focus in particular on long-term effects, personalised treatment approaches and the optimal combination and dosing of active substances.
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