Smoked CBD cigarettes as add-on for psychosis showed hints of medication-sparing effects | Research

The takeaway

In a small pilot trial of CBD cigarettes as adjunctive therapy for acute psychosis, both groups improved on symptom scores, but the placebo group required increased antipsychotic medication while the CBD group did not.

Psychiatrists researching novel antipsychotic approaches and researchers studying CBD delivery methods.

CBD group did not need antipsychotic dose increases while placebo group did

What the researchers found

No significant group differences on primary outcomes (PANSS, BDI) after 4 weeks. Both groups showed decreases in psychotic symptoms and depression scores. However, the placebo group required increases in antipsychotic medication equivalent during the trial while the CBD group did not, suggesting a potential antipsychotic medication-sparing effect of smoked CBD.

Why it matters

This is the first study to test smoked CBD (rather than oral) for psychosis. While inconclusive due to small sample size, the medication-sparing signal is clinically interesting because reducing antipsychotic doses could lower side effect burden for patients.

The numbers in context

Small sample (exact N not specified in abstract). 4-week treatment. Both groups: decreased PANSS and BDI. Placebo group: increased antipsychotic medication equivalent. CBD group: no medication increase needed.

How the study worked

Randomized, open-label pilot trial. Patients with acute psychosis received either CBD-rich cannabis cigarettes (low THC) or placebo cigarettes as adjunctive therapy to treatment as usual. Primary outcomes: PANSS (psychotic symptoms) and BDI (depression) at 4 weeks.

What this study cannot tell us

Very small sample. Open-label (not blinded). No fixed dosing regimen. Smoked delivery introduces additional variables. Cannot draw conclusions from non-significant primary outcomes with inadequate power.

How to read the evidence

Very small open-label pilot with non-significant primary outcomes. The medication-sparing observation is hypothesis-generating only.

When this study was published

2021 pilot trial from Switzerland.

The bigger picture

Previous oral CBD studies (e.g., McGuire et al., 2018) showed antipsychotic effects. This pilot extends the question to inhaled CBD, which has faster onset and different pharmacokinetics. The medication-sparing finding, if confirmed, could meaningfully improve patient quality of life.

Questions still open

Would a larger blinded trial confirm the medication-sparing effect? Is smoked CBD a practical long-term delivery method for psychosis patients? Could the act of smoking itself have placebo effects?

Common questions

Did CBD cigarettes reduce psychotic symptoms?

Both the CBD and placebo groups showed symptom improvement, with no significant difference between them. The study was too small to detect moderate-sized effects.

What was the medication-sparing effect?

Patients in the placebo group needed increases in their antipsychotic medication during the trial, while those receiving CBD cigarettes did not, suggesting CBD may reduce the need for higher antipsychotic doses.

Read the original research

Cannabidiol Cigarettes as Adjunctive Treatment for Psychotic Disorders - A Randomized, Open-Label Pilot-Study.

Frontiers in psychiatry, 12, 736822

View on PubMed ↗Publisher’s paper ↗

Citation

Köck, Patrick; Lang, Elisabeth; Trulley, Valerie-Noelle; Dechent, Frieder; Mercer-Chalmers-Bender, Katja; Frei, Priska; Huber, Christian; Borgwardt, Stefan. (2021). Cannabidiol Cigarettes as Adjunctive Treatment for Psychotic Disorders - A Randomized, Open-Label Pilot-Study.. Frontiers in psychiatry, 12, 736822. https://doi.org/10.3389/fpsyt.2021.736822