A randomized double-blind placebo-controlled crossover trial of delta-9-THC in 12 adults suffering from Gilles de la Tourette- Syndrome (Tourette-Syndrome) was conducted at the Medical School of Hanover. This syndrome is a complex neuropsychiatric disorder of unknown aetiology characterized by sudden spasms especially in the face, the neck and the shoulders and one or more vocal tics.

Patients received single doses of 5, 7.5, or 10.0 mg THC. Using both self and examiner rating scales there was a significant improvement of motor and vocal tics after treatment with THC compared with placebo. In addition, a self rating scale demonstrated a significant improvement of obsessive compulsive behaviour.

No serious adverse reactions occurred. Five patients experienced transient mild side effects such as headache, nausea, dizziness, anxiety, cheerfulness, tremble, dry mouth, and hot flush. All these side effects did not last longer than 6 hours. There were no significant differences after treatment with THC compared with placebo in verbal and visual memory, reaction time, intelligence, sustained and divided attention, vigilance, and mood.

This study followed a successful open uncontrolled study in a 25- year-old man with 10 mg of delta-9-THC, after he had reported relief from the use of marijuana to his physicians. Detailed study results are presented in two papers submitted for publication. First results are presented in an article on "Cannabis in Movement Disorders" in a supplement of the journal Research in Complementary Medicine on Cannabis in Medicine.

(Source: Mueller-Vahl KR, Kolbe H, Schneider U, Emrich H M: Cannabis in Movement Disorders. In: Grotenhermen F, Saller R (eds): Cannabis und Cannabinoide in der Medizin [Cannabis and Cannabinoids in Medicine]. Research in Complementary Medicine 6, Supplement 3, 1999)