CBD oil extract reduced anxiety symptoms in most patients over 12 months in a Colombian clinic | Research

The takeaway

In a Colombian case series of 24 adults with unspecified anxiety disorder, 12 months of CBD-enriched oil extract (100-120 mg/day) reduced the proportion with significant anxiety from 100% to 37.5%, with improvements in sleep and no significant adverse effects.

Clinicians considering CBD for anxiety treatment; researchers designing longer-term CBD trials.

Significant anxiety dropped from 100% to 37.5% over 12 months of CBD

What the researchers found

After 6 months at median 100 mg CBD daily, 54% still had significant anxiety. After 12 months at median 120 mg, only 37.5% persisted with significant symptoms. Sleep disturbances improved from 46.8% reporting significant daytime sleepiness at baseline to only 12.5% at 12 months. No clinically relevant adverse reactions or deaths occurred during follow-up.

Why it matters

This is one of the few studies tracking CBD treatment for anxiety beyond 6 months, showing continued improvement from 6 to 12 months. The real-world clinical setting adds practical relevance, though the lack of a control group limits conclusions.

The numbers in context

24 patients. Median CBD dose: 100 mg at 6 months, 120 mg at 12 months. Significant anxiety: 100% at baseline, 54% at 6 months, 37.5% at 12 months. Significant sleepiness: 47% at baseline, 29% at 6 months, 12.5% at 12 months. No depression improvement (scores were subclinical at baseline).

How the study worked

Retrospective observational case series from Zerenia Clinic, Bogota, Colombia (June 2021-December 2022). 24 adults prescribed CBD-enriched oil (100 mg/mL CBD, <1.9 mg/mL THC) for DSM-5 unspecified anxiety disorder. HADS-A, CGI-S/I, HADS-D, and ESS assessed at baseline, 6, and 12 months.

What this study cannot tell us

No control group or randomization. Very small sample (24). Unspecified anxiety disorder is a broad category. Full-spectrum extract with trace THC, not pure CBD. Cannot rule out placebo effects or natural symptom fluctuation. Retrospective design.

How to read the evidence

Small uncontrolled case series. Suggestive but cannot establish efficacy without comparison group.

When this study was published

2024 study

The bigger picture

The continued improvement between 6 and 12 months suggests CBD may require sustained use for full anxiolytic effects, which has implications for trial design and clinical expectations. The COVID-19 pandemic context adds a naturalistic stress condition.

Questions still open

Would higher doses work faster? Is the trace THC contributing to the anxiolytic effect? Would a randomized trial confirm these results?

Common questions

What dose of CBD was used?

Patients received CBD-enriched oil extract sublingually, starting at a median of 100 mg/day at 6 months and increasing to 120 mg/day by 12 months. The oil contained 100 mg/mL CBD with less than 1.9 mg/mL THC.

Does this prove CBD works for anxiety?

No. Without a control group, improvement could reflect placebo effects, natural symptom fluctuation, or other treatments. Controlled trials are needed to confirm efficacy.

Read the original research

Long-Term Treatment for Unspecified Anxiety Disorders with Cannabidiol: A Retrospective Case Series from Real-World Evidence in Colombia.

Medical cannabis and cannabinoids, 7(1), 193-205

View on PubMed ↗Publisher’s paper ↗

Citation

Galvez-Florez, Juan F; Guillen-Burgos, Hernan F; Flórez-Puentes, Camilo A; Navarro, Cristian E; Moreno-Sanz, Guillermo. (2024). Long-Term Treatment for Unspecified Anxiety Disorders with Cannabidiol: A Retrospective Case Series from Real-World Evidence in Colombia.. Medical cannabis and cannabinoids, 7(1), 193-205. https://doi.org/10.1159/000539754