Across twelve eligible studies and 146 participants, CBD doses of 100 mg to 1,000 mg were compared with placebo using fMRI, PET, or SPECT during stress- or anxiety-related tasks.

Reported activation and perfusion peaks were scattered across many cortical and subcortical regions, including the amygdala, anterior cingulate cortex, insula, and prefrontal cortex, with mixed directions of change between studies rather than one consistent pattern.

Many patients already use CBD for stress or anxiety symptoms, and product marketing often implies a settled brain mechanism behind that use.

This review shows the neuroscience is less settled than the marketing, which matters for how patients should weigh confidence versus curiosity when choosing CBD as part of their care.

The authors rated most included studies as having some concerns or high risk of bias under the Cochrane RoB 2 tool, and GRADE certainty was low to very low across outcomes.

Small samples, varied doses, varied routes of administration, and varied imaging tasks make it hard to know whether differences between studies reflect real biology or methodological noise.

The review does not identify a validated brain biomarker for CBD response, does not establish which dose or route best engages stress circuitry, and does not resolve whether sex differences shape the neural response.

It also does not address whether a clear neural signal would even be necessary for CBD to provide meaningful symptom relief, since subjective benefit and measurable brain change are not the same question.

CBD sits at an unusual point in cannabis medicine: patient interest and product availability have outpaced the neuroscience explaining how it works, even as behavioral and self-report evidence for anxiety benefit continues to accumulate elsewhere in the literature.

A null or inconsistent neuroimaging result does not cancel out that behavioral evidence. It simply means the field cannot yet point to a specific, reproducible brain circuit as proof of mechanism, and should stop implying otherwise in patient-facing materials.

I read this review as a useful correction to overconfident mechanism talk, not as a reason to dismiss CBD for anxiety. Patients report benefit, and that self-report evidence deserves to be taken seriously on its own terms.

What this paper tells me is that when I discuss CBD with an anxious patient, I should describe it as a compound with promising but still-unproven neural mechanisms, not as a substance with a demonstrated brain-based anxiolytic pathway. That distinction protects patient trust.

A Four-Step Reading Frame