Synthetic cannabinoid users showed significantly worse executive function than both cannabis users and non-users | Research

The takeaway

Chronic synthetic cannabinoid users performed significantly worse on memory, attention, and inhibition tasks compared to both recreational cannabis users and non-users, and also reported higher depression and anxiety.

Read this if you want to understand how synthetic cannabinoids affect the brain differently from natural cannabis.

Synthetic cannabinoid users performed significantly worse than cannabis users on all cognitive tests

What the researchers found

Across two study sites (Hungary and Israel), 38 synthetic cannabinoid users were compared with 43 recreational cannabis users and 41 non-users on computerized cognitive tests.

Synthetic cannabinoid users performed significantly worse than both other groups on the n-back task (working memory accuracy), the Stroop task (response speed and accuracy, measuring inhibition), and a free-recall memory task (long-term memory). They also reported higher ratings of depression and anxiety.

Importantly, recreational cannabis users did not show the same degree of impairment, suggesting that the cognitive deficits are specific to synthetic cannabinoids rather than cannabinoid exposure in general.

Why it matters

This is one of the first studies directly comparing cognitive function between synthetic cannabinoid users, natural cannabis users, and non-users. The finding that synthetic cannabinoid users are significantly more impaired than cannabis users provides evidence that these substances are genuinely more damaging to the brain, not just pharmacologically stronger.

The numbers in context

38 synthetic cannabinoid users vs 43 cannabis users vs 41 non-users. Synthetic users: lower n-back accuracy, slower and less accurate Stroop performance, fewer words recalled. Higher depression and anxiety ratings. Two-country sample (Hungary, Israel).

How the study worked

Cross-sectional comparison of three groups from two centers (Hungary and Israel). Cognitive testing included computerized n-back task (working memory), classical Stroop word-color task (inhibition), and free-recall memory task (long-term memory). Depression and anxiety were also assessed.

What this study cannot tell us

Cross-sectional design cannot determine whether cognitive differences existed before drug use. Synthetic cannabinoid users may differ from cannabis users in polysubstance use, socioeconomic status, or other factors. The study did not control for specific synthetic cannabinoid products used. Small sample sizes limit statistical power.

How to read the evidence

Multi-site observational study with appropriate control groups. Good design but limited by cross-sectional nature and small samples.

When this study was published

Published in 2017. Research on cognitive effects of synthetic cannabinoids has grown as these substances remain a global concern.

The bigger picture

Synthetic cannabinoids are often used by populations who cannot access natural cannabis (military, prisoners, people in drug-tested employment). The finding that these substances cause greater cognitive impairment than cannabis itself, while also being more addictive and dangerous, strengthens the public health argument for making natural cannabis more accessible where appropriate.

Questions still open

Are the cognitive impairments reversible with abstinence? Do specific synthetic cannabinoids cause more damage than others? Would longitudinal studies confirm that synthetic cannabinoids cause these deficits rather than just being used by people with pre-existing cognitive differences?

Common questions

Are synthetic cannabinoids worse for your brain than marijuana?

This study found that synthetic cannabinoid users had significantly worse performance on memory, attention, and inhibition tasks compared to recreational cannabis users. While the cross-sectional design cannot prove causation, the pattern suggests synthetic cannabinoids are more harmful to cognitive function.

Why would someone use synthetic cannabinoids instead of marijuana?

Synthetic cannabinoids are often used because they are harder to detect on drug tests, may be cheaper or more accessible in some contexts, and were historically legal in some jurisdictions. However, they carry far greater health risks than natural cannabis.

Read the original research

The effects of synthetic cannabinoids on executive function.

Psychopharmacology, 234(7), 1121-1134

View on PubMed ↗Publisher’s paper ↗

Citation

Cohen, K; Kapitány-Fövény, M; Mama, Y; Arieli, M; Rosca, P; Demetrovics, Z; Weinstein, A. (2017). The effects of synthetic cannabinoids on executive function.. Psychopharmacology, 234(7), 1121-1134. https://doi.org/10.1007/s00213-017-4546-4