Review finds weak but suggestive evidence for cannabinoids in anxiety and PTSD, with depression potentially worsened by cannabis | Research

The takeaway

Recent evidence suggests CBD and CBD-enriched cannabis may have anxiolytic properties and reduce fear/stress responses in PTSD, but depression may worsen with cannabis use, and well-designed RCTs are largely absent.

Psychiatrists, people considering cannabis for anxiety or PTSD, mental health researchers

Evidence suggests CBD may help anxiety and PTSD but cannabis may worsen depression

What the researchers found

Some evidence suggests cannabinoids, CBD, or CBD-enriched cannabis have anxiety-reducing properties. Depression may be worsened by cannabis use, though RCTs are lacking. New evidence indicates CBD or CBD-enriched cannabis for PTSD and emotion regulation can induce reduced responses to fear and stress. The endocannabinoid system appears to be a key player in anxiety and PTSD.

Why it matters

With increasing medicinal use and social tolerance of cannabis, understanding which psychiatric conditions might benefit or worsen from cannabinoid use is clinically urgent.

The numbers in context

No pooled effect sizes; the review summarizes trends across recent publications.

How the study worked

Review of evidence published in the 18 months prior to publication on cannabis and cannabinoids in relation to anxiety, depression (unipolar and bipolar), PTSD, and emotionally unstable personality disorders. Also covers endocannabinoids as potential biomarkers.

What this study cannot tell us

Weak evidence overall; lack of well-designed RCTs for most conditions reviewed; heterogeneous cannabinoid preparations; most anxiety/PTSD findings are preliminary.

How to read the evidence

Review of recent literature highlighting the absence of well-designed RCTs for most conditions.

When this study was published

Published in 2020.

The bigger picture

The contrast between possible benefits for anxiety/PTSD and possible worsening of depression underscores that cannabinoids are not universally helpful for mental health and that specific conditions may require different approaches.

Questions still open

Could CBD be effective for anxiety and PTSD without the depression risk associated with THC-containing cannabis? What endocannabinoid biomarkers could guide treatment selection?

Common questions

Should people with anxiety use cannabis?

The review found some evidence that CBD and CBD-enriched preparations may have anxiety-reducing properties, but the evidence is weak and well-designed clinical trials are lacking. THC-containing cannabis may have different effects than CBD alone.

Does cannabis worsen depression?

The review suggests depression may be worsened by cannabis use based on recent evidence, though randomized controlled trials specifically testing this are lacking. The relationship between cannabis and depression likely depends on the type of cannabinoid, dose, and individual factors.

Read the original research

Cannabinoids and the endocannabinoid system in anxiety, depression, and dysregulation of emotion in humans.

Current opinion in psychiatry, 33(1), 20-42

View on PubMed ↗Publisher’s paper ↗

Citation

Chadwick, Verity L; Rohleder, Cathrin; Koethe, Dagmar; Leweke, F Markus. (2020). Cannabinoids and the endocannabinoid system in anxiety, depression, and dysregulation of emotion in humans.. Current opinion in psychiatry, 33(1), 20-42. https://doi.org/10.1097/YCO.0000000000000562