Influence of Treatment of Tourette Syndrome with Δ9-Tetrahydrocannabinol (Δ9-THC) on Neuropsychological Performance

Abstract

Previous studies have suggested that marijuana (cannabis sativa) and delta-9-tetrahydrocannabinol (delta9-THC), the major psychoactive ingredient of marijuana, are effective in the therapy of tics and associated behavioral disorders in Tourette Syndrome (TS). Because there is also evidence that cannabis sativa may cause cognitive impairment in healthy users, we performed a randomized double-blind placebo-controlled crossover trial for delta9-THC in 12 adult TS patients to investigate whether treatment of TS with a single dose of delta9-THC at 5.0 to 10.0 mg causes significant side effects on neuropsychological performance. Using a variety of neuropsychological tests, we found no significant differences after treatment with delta9-THC compared to placebo treatment in verbal and visual memory, reaction time, intelligence, sustained attention, divided attention, vigilance, or mood. Only when using the Symptom Checklist 90-R (SCL-90-R) did our data provide evidence for a deterioration of obsessive-compulsive behavior (OCB) and a trend towards an increase in phobic anxiety. However, these results should be interpreted with caution as SCL-90-R has known limitations on measuring OCB. We suggest that the increase in phobic anxiety is mainly due to the fact that a single-dose treatment rules out the possibility of administering the dosage slowly. In contrast to results obtained from healthy marijuana users, a single-dose treatment with delta9-THC in patients suffering from TS does not cause cognitive impairment. We therefore suggest that further investigations should concentrate on the effects of a longer-term therapy of TS with delta9-THC.

The treatment of spasticity with Δ9-tetrahydrocannabinol in persons with spinal cord injury

“…Mu¨ller-Vahl et al 40 found no significant side effects on neuropsychological performance of single dose of oral THC at 5.0-10.0 mg in 12 patients with Tourette's syndrome. There were no significant differences after treatment with verum compared to placebo in verbal and visual memory, reaction time, intelligence, sustained attention, divided attention, vigilance or mood.…”

Treatment of Tourette Syndrome with Cannabinoids

“…In addition, there is some weak evidence that cannabinoids may improve also associated behavioural problems such as OCB, attention span, impulsivity, and autoaggression. Since neuropsychological tests failed to demonstrate detrimental effects of THC on memory, reaction time, concentration, and attention [15,25,30], it can be assumed that beneficial effects in patients with TS are caused by specific effects rather than secondary mechanisms due to sedation or decreased general activity. Since CB1 receptors are not only highly located in those brain regions that are thought to be involved in TS pathology, but also have a complex interaction with the dopaminergic system, it can be speculated that beneficial effects in TS are mediated directly though the central CB1 receptor system.…”

“…In the single-dose cross-over study a variety of neuropsychological tests was performed, but no detrimental effects of THC could be detected on short-term verbal and visual memory, recognition, verbal learning, intelligence, information processing, vigilance, reaction time, sustained attention and divided attention [25].…”

Cannabis in Movement Disorders

“…Five patients experienced transient mild side effects. Measuring cognitive functions, neuropsychological tests showed no significant differences after treatment with D 9 -THC compared with placebo treatment in verbal and visual memory, reaction time, intelligence, sustained attention, divided attention, vigilance, and mood [31,34].…”