←Tourette Syndrome

Study register · detail RCT (doppelblind, placebokontrolliert) · Tourette Syndrome · 2003

Treatment of Tourette syndrome with delta-9-tetrahydrocannabinol (delta 9-THC): no influence on neuropsychological performance.

Müller-Vahl et al. ·Neuropsychopharmacology Impact 4.4

No benefit demonstrated GRADE Moderate 107 citations

Samplen = 24 Pat.

Duration6 weeks plus 5–6 weeks…

ControlPlacebo

EndpointNeuropsychological performance

Blindingdoppelblind

DesignRCT (doppelblind, placebokontrolliert)

Cannabinoidthc

Max. dose10.0 mg

Routeoral

Key finding

Delta-9-THC had no negative influence on neuropsychological performance in Tourette patients.

Summary

n=24 Tourette patients, delta-9-THC up to 10 mg over 6 weeks vs. placebo; no negative influence on learning curve, interference, recall, visual memory, or divided attention; trend toward significant improvement in immediate verbal memory under THC (p-value in trend); THC shows neither acute nor long-term cognitive deficits in TS patients.

PopulationAdults with Tourette syndrome, n=24

InterventionDelta-9-THC oral up to 10 mg/day over 6 weeks

ControlPlacebo

OutcomeNo adverse effect on neuropsychological performance (learning curve, interference, memory, divided attention); trend toward improvement in immediate verbal memory

Confidence in the evidence

Moderate

The third of four GRADE levels, the effect estimate is probably reliable.

Downgraded for

Imprecision

Quality profile

Sample size ★★★★★

Blinding Double-blind

Effect size No benefit

Citations / year ★★★★★

Authors

Müller-Vahl KR, Prevedel H, Theloe K, Kolbe H, Emrich HM, Schneider U.

DOI 10.1038/sj.npp.1300047↗

Design: RCT (doppelblind, placebokontrolliert)

Abstract

Previous studies provide evidence that Cannabis (Cannabis sativa) and delta-9-tetrahydrocannabinol (Delta(9)-THC), the major psychoactive ingredient of Cannabis, respectively, are effective in the treatment of tics and behavioral problems in Tourette syndrome (TS). It, therefore, has been speculated that the central cannabinoid receptor system might be involved in TS pathology. However, in healthy Cannabis users there is an ongoing debate as to whether the use of cannabis causes acute and/or long-term cognitive deficits. In this randomized double-blind placebo-controlled study, we investigated the effect of a treatment with up to 10 mg Delta(9)-THC over a 6-week period on neuropsychological performance in 24 patients suffering from TS. During medication and immediately as well as 5-6 weeks after withdrawal of Delta(9)-THC treatment, no detrimental effect was seen on learning curve, interference, recall and recognition of word lists, immediate visual memory span, and divided attention. Measuring immediate verbal memory span, we even found a trend towards a significant improvement during and after treatment. Results from this study corroborate previous data suggesting that in patients suffering from TS, treatment with Delta(9)-THC causes neither acute nor long-term cognitive deficits. Larger and longer-duration controlled studies are recommended to provide more information on the adverse effect profile of THC in patients suffering from TS.

The impediment to action advances action. — Marcus Aurelius