Plain language and scientific honesty: for each condition, we explain how treatment is usually considered, what studies have shown so far, and what they haven't.
Strong evidence
There are good-quality randomized clinical trials, and cannabinoid-based medicines have been approved by regulatory agencies for this indication.
Moderate evidence
Clinical studies show benefit for some patients, but results vary and there are still open questions about the ideal dose and which patients benefit most.
Emerging evidence
Studies are promising but still small or at an early stage. Use may be considered with caution, individual assessment and close follow-up.
Seizures that keep happening even when two or more anti-seizure medications are taken correctly.
Cannabidiol (CBD) may be added to existing treatment to help reduce how often seizures occur in some syndromes. It is introduced gradually, together with the neurologist, and requires attention to interactions with other anti-seizure medications, such as clobazam and valproate.
What the studies say: Randomized clinical trials led to the approval of purified CBD in other countries for Dravet syndrome, Lennox-Gastaut syndrome and tuberous sclerosis complex.
Pain that lasts more than three months, including pain caused by nerve damage or dysfunction, such as burning, electric-shock sensations or tingling.
Cannabinoids act on nervous system pathways involved in how we perceive pain and may help some people reduce pain intensity and improve their sleep and day-to-day functioning. They are usually part of a broader plan, which may include other medications, physical therapy and changes to daily routine.
What the studies say: Systematic reviews show a modest benefit in some patients, especially for neuropathic pain. The response is highly individual.
Stiffness and involuntary muscle contractions that make movement difficult and can cause pain in people with multiple sclerosis.
Combinations of THC and CBD may help reduce muscle stiffness and spasms in patients who have not responded well to other treatments. The assessment takes into account the degree of spasticity, the medications already in use and the patient's functional goals.
What the studies say: A medicine containing THC and CBD is registered in Brazil for this indication, and clinical studies show benefit in some patients.
Nausea and vomiting caused by cancer treatment, which may persist even with the usual anti-nausea medications.
Cannabinoids may be considered as a complementary therapy when conventional anti-nausea medications are not enough. Treatment is always coordinated with the oncology team.
What the studies say: Synthetic cannabinoids are approved in other countries for this indication. They are generally used as a complement rather than as a first choice.
Managing symptoms such as pain, loss of appetite, nausea and sleep problems in people with serious or advanced illness.
In palliative care, the goal is comfort and quality of life. Medical cannabis may help manage several symptoms at once, always in coordination with the team caring for the patient.
What the studies say: Results vary depending on the symptom assessed. Benefit has been described for appetite and nausea in some settings; for other symptoms, the data are still limited.
A syndrome marked by widespread pain throughout the body, fatigue, unrefreshing sleep and changes in mood and concentration.
Some people report improvement in pain, sleep and their overall sense of wellbeing. Because fibromyalgia has many components, medical cannabis is usually just one part of care, alongside guided physical activity, good sleep and emotional health.
What the studies say: The available studies are small, with mixed results. Larger studies are still needed to confirm any benefit.
Difficulty falling asleep, staying asleep through the night or waking up rested, with an impact on the following day.
Medical cannabis may be considered when insomnia is linked to pain, anxiety or other conditions, and almost always alongside sleep hygiene measures. Before any prescription, it's important to look into what is causing the insomnia.
What the studies say: There are promising early studies, but still few robust clinical trials focused specifically on insomnia.
Excessive worry, tension, restlessness and physical symptoms that interfere with daily life, work and relationships.
CBD has been studied for its possible anti-anxiety effect. When appropriate, it is used with caution and follow-up, without replacing psychotherapy or other mental health care. Formulations with THC call for extra care, since higher doses can increase anxiety.
What the studies say: Small and experimental studies suggest a benefit from CBD, but larger, long-term clinical trials are still lacking.
Support in managing symptoms associated with autism spectrum disorder, such as irritability, agitation, aggression and sleep problems.
In some children and adults, medical cannabis may help with associated symptoms, always as part of care that includes therapies, follow-up by a multidisciplinary team and close involvement of the family. The goal is not to treat autism itself, but to support quality of life.
What the studies say: There are early clinical trials with encouraging results, but they are still limited in size and duration.
Symptoms beyond tremor and stiffness, such as pain, sleep problems, anxiety and restlessness, which can greatly affect quality of life.
Medical cannabis has been studied as a complement for some non-motor symptoms, without replacing the main neurological treatment. It is introduced carefully, especially in older adults, because of the risk of drowsiness and dizziness.
What the studies say: The available data come mainly from small studies. There is no evidence that it changes how the disease progresses.