Sativex Did Not Impair Cognitive Function in MS Patients Over 6 Months | Research

The takeaway

Cannabis-naive multiple sclerosis patients treated with Sativex for spasticity showed no significant cognitive or behavioral decline over 6 months of treatment, with only one exception among 40 patients.

Read this if you have MS and are considering Sativex or other cannabis-based medications for spasticity.

39 of 40 MS patients showed no cognitive decline after 6 months of Sativex treatment.

What the researchers found

Forty cannabis-naive multiple sclerosis patients were assessed with comprehensive neuropsychological testing before starting Sativex treatment and again at 1 and 6 months. The study specifically targeted patients who had never used cannabis to isolate the drug's cognitive effects from pre-existing cannabis exposure.

After 6 months of Sativex use, no significant neurobehavioral impairment was observed across the group. Only one patient out of 40 showed cognitive changes, confirming that significant side effects are uncommon but not impossible.

The authors recommended that MS patients should undergo extensive neuropsychological evaluation before starting Sativex, to enable detection of any rare but important individual adverse effects.

Why it matters

A major concern about cannabis-based medications is their potential to impair cognition, which is particularly relevant for MS patients who already face cognitive challenges from their disease. This study provides reassurance that Sativex, used as prescribed for spasticity, does not add significant cognitive burden.

The numbers in context

40 cannabis-naive MS patients. No significant neurobehavioral impairment at 1 or 6 months. 1 out of 40 patients showed cognitive changes.

How the study worked

Prospective cohort study of 40 cannabis-naive MS patients. All underwent clinical and neuropsychological assessment at baseline and after 1 and 6 months of Sativex treatment. Testing covered spasticity, associated symptoms, and the cognitive and psychiatric domains commonly impaired in MS.

What this study cannot tell us

The sample was relatively small (40 patients). There was no placebo control group, so any cognitive changes from MS progression itself cannot be isolated from treatment effects. Six months may not be long enough to detect slow-onset cognitive effects. The single patient who showed changes demonstrates that individual variation exists.

How to read the evidence

Moderate evidence from a prospective study with comprehensive neuropsychological testing, though limited by small sample size and lack of placebo control.

When this study was published

Published in 2016. Sativex continues to be used for MS spasticity in many countries.

The bigger picture

This study adds to the evidence that pharmaceutical cannabinoid products used at therapeutic doses may not carry the cognitive risks associated with recreational cannabis use. The 6-month follow-up provides longer-term data than most studies, though even longer monitoring would be valuable.

Questions still open

Would longer treatment periods (years) reveal any gradual cognitive effects? What distinguished the one patient who showed cognitive changes from the other 39? Would results differ in patients with more advanced MS or existing cognitive impairment?

Common questions

Does Sativex affect thinking and memory?

In this study of 40 MS patients over 6 months, Sativex did not significantly affect cognitive or behavioral function. One patient out of 40 showed changes, suggesting that while generally safe, individual monitoring is recommended.

Is Sativex different from recreational cannabis for cognition?

Sativex contains standardized doses of THC and CBD. This study in cannabis-naive patients suggests it does not impair cognition at therapeutic doses, which may differ from effects of recreational cannabis at higher, variable doses.

Read the original research

Should we care about sativex-induced neurobehavioral effects? A 6-month follow-up study.

European review for medical and pharmacological sciences, 20(14), 3127-33

View on PubMed ↗

Citation

Russo, M; De Luca, R; Torrisi, M; Rifici, C; Sessa, E; Bramanti, P; Naro, A; Calabrò, R S. (2016). Should we care about sativex-induced neurobehavioral effects? A 6-month follow-up study.. European review for medical and pharmacological sciences, 20(14), 3127-33.