A critical review found CBD shows promise for psychosis, anxiety, and substance withdrawal through distinct pharmacological pathways | Research

The takeaway

A review of clinical studies found evidence that CBD may reduce psychotic symptoms through endocannabinoid facilitation and CB1 antagonism, reduce anxiety through serotonin 1A receptor agonism and cerebral blood flow changes, and reduce cannabis/tobacco withdrawal through endocannabinoid and serotonergic modulation.

Psychiatrists evaluating CBD as a therapeutic option; researchers designing CBD clinical trials; patients interested in evidence-based CBD applications.

CBD acts through different mechanisms for psychosis, anxiety, and addiction

What the researchers found

Researchers reviewed all clinical studies investigating CBD as treatment for psychiatric symptoms and linked findings to pharmacological mechanisms.

For schizophrenia: CBD may exert antipsychotic effects primarily through facilitation of endocannabinoid signaling and CB1 receptor antagonism. Clinical data support this application.

For anxiety: CBD showed acute anxiolytic effects in patients with generalized social anxiety disorder through modification of cerebral blood flow in specific brain regions and serotonin 1A receptor agonism.

For addiction: CBD may reduce cannabis and tobacco withdrawal symptoms through modulation of endocannabinoid, serotonergic, and glutamatergic systems.

For cognition: Despite promising preclinical pro-cognitive effects, clinical studies in psychiatric disorders have not shown significant cognitive benefits.

The authors concluded that larger randomized controlled trials and biological measures are needed to confirm these effects.

Why it matters

Understanding not just whether CBD works but how it works for different psychiatric conditions is essential for developing targeted therapies. This review organizes the evidence by condition and mechanism, providing a framework for future research.

The numbers in context

Antipsychotic effects linked to endocannabinoid facilitation and CB1 antagonism. Anxiolytic effects linked to serotonin 1A agonism and cerebral blood flow modification. Withdrawal reduction linked to endocannabinoid, serotonergic, and glutamatergic modulation.

How the study worked

Critical review of clinical studies from PubMed database investigating CBD as treatment for psychiatric symptoms. Focused on linking clinical efficacy to pharmacological mechanisms of action.

What this study cannot tell us

Current clinical studies are small and often lack adequate controls. The review is narrative rather than systematic. Different psychiatric conditions may require different CBD doses and formulations. The pro-cognitive effects that seem promising in animal studies have not translated to human psychiatric populations.

How to read the evidence

Moderate. Well-organized mechanistic review of clinical evidence, but limited by the small size of underlying studies.

When this study was published

Published in 2018. CBD research in psychiatry has expanded significantly, with several larger trials completed since.

The bigger picture

CBD is increasingly being explored as a psychiatric medication rather than just a wellness product. This review helps distinguish evidence-based psychiatric applications from marketing hype by focusing on specific mechanisms and clinical data.

Questions still open

What CBD doses are optimal for each psychiatric condition? Can CBD replace existing antipsychotics or only augment them? Why do preclinical cognitive benefits not translate to psychiatric populations?

Common questions

Can CBD replace antipsychotic medications?

Current evidence suggests CBD may have antipsychotic properties, but studies are small and preliminary. It is most studied as an adjunctive (add-on) treatment rather than a replacement for existing antipsychotics. Any medication changes should be discussed with a psychiatrist.

Why does CBD work differently for anxiety versus psychosis?

CBD interacts with multiple receptor systems in the brain. Its anxiolytic effects appear to work mainly through serotonin 1A receptors, while its antipsychotic effects work through the endocannabinoid system and CB1 receptors. This multi-target pharmacology is part of what makes CBD unusual as a potential psychiatric medication.

Read the original research

Pharmacological properties of cannabidiol in the treatment of psychiatric disorders: a critical overview.

Epidemiology and psychiatric sciences, 27(4), 327-335

View on PubMed ↗Publisher’s paper ↗

Citation

Mandolini, G M; Lazzaretti, M; Pigoni, A; Oldani, L; Delvecchio, G; Brambilla, P. (2018). Pharmacological properties of cannabidiol in the treatment of psychiatric disorders: a critical overview.. Epidemiology and psychiatric sciences, 27(4), 327-335. https://doi.org/10.1017/S2045796018000239