Cannabis comes up in my practice for two reasons: patients who are already using it and want to know whether it's helping or hurting them, and patients who are considering medical cannabis for a specific condition and want a physician's read. Here's a clinical view of what the evidence actually supports, where it doesn't, and how I think about it in practice.
The compounds
The cannabis plant contains over a hundred cannabinoids. The two that matter clinically are THC (tetrahydrocannabinol) and CBD (cannabidiol). THC is primarily responsible for the psychoactive effect. CBD is non-intoxicating and has a different effect profile. Most products on the medical and recreational market today are a mix; the ratio matters for both efficacy and side effects.
How it works in the body
Humans have an endocannabinoid system, a signaling network of receptors (primarily CB1 and CB2), naturally produced cannabinoids, and enzymes that break them down. This system is involved in pain modulation, appetite, mood, immune function, and sleep, among other things. Cannabis compounds work by interacting with these receptors.
This biology is real and explains why cannabis has effects across so many different systems. It also explains the variability in response between patients.
Where the evidence actually supports medical use
The evidence base is uneven. For some conditions it's solid. For others it's thin or mixed. A fair summary:
Chronic pain. Evidence supports use for specific pain conditions, particularly neuropathic pain and cancer-related pain, when conventional treatments are inadequate. Effects are often modest and variable between patients.
Chemotherapy-induced nausea and vomiting. Well-established. Two synthetic THC-based medications (dronabinol, nabilone) are FDA-approved for this indication.
Spasticity in multiple sclerosis. Evidence supports use; a cannabinoid-based medication (nabiximols) is approved in several countries though not yet in the U.S.
Epilepsy. Specific forms of pediatric epilepsy (Dravet syndrome, Lennox-Gastaut) respond to CBD. Epidiolex, a plant-derived CBD, is FDA-approved for these indications.
Sleep. Some patients experience meaningful improvement in sleep with appropriate dosing, particularly for insomnia related to chronic pain or PTSD. Evidence is mixed.
Anxiety. Low-dose CBD and certain THC/CBD combinations may help some patients. High-dose THC often makes anxiety worse, especially in patients who are not experienced users. Not a first-line treatment.
PTSD. Active research area with preliminary evidence. Not yet standard of care.
Where the evidence is thin or the risk-benefit is unfavorable
Cannabis is not a universal therapeutic. For many conditions it's promoted for, the evidence is weak or absent. For some conditions, it's contraindicated or can make things worse. Important examples:
- Psychotic disorders: cannabis can precipitate or worsen psychosis, particularly in young people and those with a personal or family history of schizophrenia
- Heavy or daily high-THC use in adolescents and young adults: associated with changes in cognition, motivation, and mental health
- Cardiovascular disease: THC can raise heart rate and blood pressure; caution in patients with unstable cardiac disease
- Pregnancy: not recommended; effects on fetal development are real
Regulation and access
Legal status varies widely. As of this writing:
- United States: state-by-state medical and recreational programs, with federal prohibition still in place. Florida has a medical cannabis program requiring physician certification for qualifying conditions.
- Canada: fully legal for medical and recreational use
- Europe: mixed, with many countries allowing medical use
- Australia: medical cannabis legal with prescription
In Florida, patients interested in medical cannabis typically need a qualifying condition (chronic pain, cancer, epilepsy, PTSD, and several others) and certification from a physician authorized to do so.
What I tell patients considering it
A few practical points:
Start low, go slow. The right dose for a given patient is often much lower than what they expect. Starting at a low dose and titrating slowly over days to weeks reduces side effects and helps find the minimum effective dose.
Delivery method matters. Inhalation (smoking or vaping) has rapid onset and short duration. Edibles have slow onset, long duration, and are easy to over-dose. Tinctures and oils are in between. The right choice depends on the indication.
Know the product. Legal medical and recreational dispensaries provide labeled products with known cannabinoid content. Unregulated products can have wildly variable potency and contamination. For medical use specifically, labeled dosing matters.
Drug interactions are real. Cannabis can interact with blood thinners, certain psychiatric medications, some anti-seizure drugs, and others. Review medications with a physician before adding cannabis.
It's not a first-line treatment for most things. When evidence supports cannabis, it's usually as an adjunct or when other treatments have failed. It's rarely the best opening move.
How I approach this in practice
For patients using cannabis recreationally, the conversation is about risk mitigation: dose, frequency, interactions with medications, cardiovascular considerations, and mental health.
For patients considering medical cannabis for a specific condition, the conversation is about whether the evidence supports the use, what realistic expectations are, and how to structure a trial that actually tells us whether it's working.
The right approach is honest and specific, not enthusiastic or prohibitionist.
If you want to talk through whether cannabis fits your specific clinical situation, reach out. I can give you a realistic read and help you think through the decision.
This post is educational and not medical advice. Any cannabis use should be discussed with your physician, particularly if you have active medical conditions or are taking medications.
