Medication Management

Cannabis, CBD and Psychiatric Medication

By Dr. Stacey Forbes, DNP, APRN, PMHNP-BC · Updated October 12, 2026

Cannabis and CBD can interact with psychiatric medication in two main ways. CBD changes how the liver clears some drugs, and both CBD and THC add to the sedation of anxiety and sleep medications and alcohol. THC also carries its own psychiatric risks, especially psychosis in people who are vulnerable. Evidence that cannabis treats anxiety or insomnia is thinner than marketing suggests, and product labels are often inaccurate. None of this is a reason to hide your use. Your prescriber can only plan around what they know.

CBD, THC and hemp: what people mean

“Cannabis” covers a range of products. THC is the compound that causes a high. CBD does not cause a high but is active in the body. Hemp is cannabis legally defined by its low THC content, and it is the source of most CBD sold in shops and online. Many products blend the two, and some “hemp” products are designed to deliver THC.

Only one CBD product is FDA-approved: Epidiolex, a purified prescription CBD for certain seizure disorders. The FDA has concluded that CBD products are excluded from the definition of a dietary supplement and that adding CBD or THC to food sold across state lines is prohibited. The CBD oils, gummies and drinks on store shelves are therefore not reviewed for dose, purity or interactions.

How CBD changes other medications

Because Epidiolex is an approved drug, its label contains the best-quality interaction data available for CBD. It describes cannabidiol as a moderate inhibitor of CYP2C19 and a weak inhibitor of CYP1A2, with effects on several other enzymes and transporters. When an enzyme is inhibited, medicines it clears can build up.

The label’s clearest psychiatric example involves clobazam, a benzodiazepine. Taken with CBD, the level of clobazam’s active breakdown product rose about threefold, and sleepiness was much more common in people taking both. CYP2C19 also helps clear several commonly prescribed antidepressants and benzodiazepines, so similar effects are plausible, and the label advises considering dose reductions of CYP2C19-dependent drugs.

Two honest caveats. First, the label data come from prescription-strength CBD; how much of this applies to lower-strength retail products is less well studied. Second, CBD is often described online as a strong CYP3A4 blocker, but the Epidiolex label reports that CBD did not change levels of midazolam, a sensitive CYP3A4 test drug. The interaction picture is real but more specific than many websites suggest.

The label also reports liver enzyme elevations, more often when CBD is combined with valproate. If you take valproate and use CBD, your prescriber needs to know so they can watch your liver tests; see our guide to lab monitoring for psychiatric medications.

Sedation stacking

The Epidiolex label lists sleepiness and sedation as common effects and warns that combining CBD with other central nervous system depressants, including alcohol, may increase that risk. THC is sedating in many people too. Layered on a benzodiazepine, a sleep medication, a sedating antidepressant or antipsychotic, gabapentin, an opioid or alcohol, the effects add up.

The risks are practical: impaired driving, next-day fogginess, falls and, with heavier combinations, slowed breathing. It is the same principle we describe for herbs in our guide to supplement and medication interactions, and for alcohol in alcohol and psychiatric medication.

THC, psychosis and mood

The National Institute on Drug Abuse (NIDA) reports that cannabis use has been linked to earlier onset of psychosis in people with genetic risk factors for psychotic disorders, that the association with schizophrenia is especially strong in young males, and that intoxication at high doses can cause a temporary psychotic episode. NIDA also notes that dispensary flower and concentrates can exceed 40 percent THC and that higher THC concentrations are associated with a greater likelihood of cannabis use disorder.

The relationship between cannabis and bipolar disorder is less settled in the research, but because THC can affect sleep, motivation and mood stability, it is worth discussing openly if you have a mood disorder. Our page on integrative medication management for bipolar disorder explains how sleep and substances fit into a stability plan.

Cannabis for anxiety and sleep: what the evidence says

Many people use cannabis or CBD to settle anxiety or to sleep, and some feel it helps. The research is less confident. NCCIH summarizes the evidence for anxiety as a small amount from studies in people, and says the effects on sleep in people without other illnesses are uncertain. Regular THC use can also lead to tolerance and to rebound anxiety or poor sleep when use stops, which can be mistaken for the original problem returning.

If cannabis is part of how you are managing symptoms, that is useful information rather than a failing. It may point to a gap in your current treatment that can be filled more reliably. Our guides to anxiety that does not respond to medication and why sleep medication may not be fixing insomnia cover other options.

What is actually in the bottle

A study published in JAMA tested 84 CBD products sold online. Only about 31 percent were accurately labeled for CBD; roughly 43 percent contained less than stated and 26 percent contained more. THC was detected in 18 of the 84 products. NCCIH similarly warns that over-the-counter CBD products may contain more or less CBD than their labels state.

This matters for interactions. A product that contains far more CBD than labeled can produce stronger enzyme effects, and an unlabeled THC content can cause sedation, anxiety or a positive drug test. If you use CBD, choose a product with a batch-specific certificate of analysis from an independent lab, bring the label to your visit, and keep to one product so effects can be tracked.

Laws vary by state and are changing

The six states where Willow & Stone sees patients take very different approaches, ranging from adult-use markets to tightly limited medical programs, and those rules change. Legal status does not change the pharmacology: an interaction is the same whether a product came from a dispensary, a gas station or a prescription.

Federal hemp rules are also shifting. A 2025 federal law redefines hemp to count total THC, including THCA, excludes cannabinoids made synthetically or converted outside the plant, and sharply limits the total THC allowed per container in finished hemp products. Under a September 2026 law, only the synthetic-cannabinoid provisions apply until December 11, 2026, when the rest is currently scheduled to take effect. The date has already moved once, so products on shelves today may change.

How to tell your prescriber, without judgment

Cannabis use is common, and a good prescriber asks about it the same way they ask about caffeine or alcohol. To make the conversation useful:

• Say what you use (CBD, THC or both), the form (smoked, vaped, edible, oil), roughly how often, and when in the day.
• Bring the product label or a photo, especially for CBD.
• Mention what you use it for, such as sleep, anxiety, pain or appetite.
• Note any changes you have noticed: sleep, mood, motivation, anxiety after use wears off.
• Ask directly whether any of your medications are affected.

At Willow & Stone, Dr. Stacey Forbes reviews cannabis and CBD as part of every medication list. The aim is safety: choosing medications less affected by CBD, adjusting monitoring, and, if you want to cut back, planning that with support. You can see how this fits our approach to integrative medication management or book a consultation.

Common Questions

Sources & Further Reading

• DailyMed — Epidiolex (cannabidiol) prescribing information
• FDA — Regulation of Cannabis and Cannabis-Derived Products, Including Cannabidiol (CBD)
• Bonn-Miller MO et al. — Labeling Accuracy of Cannabidiol Extracts Sold Online (JAMA, 2017)
• NIDA — Cannabis (Marijuana)
• NCCIH — Cannabis (Marijuana) and Cannabinoids: What You Need To Know
• Congress.gov — Public Law 119-37, sec. 781 (hemp definition)
• Congress.gov — H.R. 6500 enrolled text (Pub. L. 119-103), sec. 2019 (Section 781 extension)

This article is general education, not advice for your situation. Do not start, stop, or change a medication or supplement without talking to the clinician who prescribes it.