Tourette’s syndrome usually begins in childhood and is characterized by motor and vocal tics (involuntary rapid repetitive movements or vocalizations). It has been suggested that the symptoms might be mediated by a reduction in the activity of limbic-basal ganglia-thalamocortical circuits. These circuits, while not well understood, appear to be responsible for translating a person’s intentions to move into actual movements. Damage to these structures leads to either involuntary increases in movement (as in Huntington’s disease) or the inability to make voluntary movements (as in Parkinson’s disease). The nature of the deficit in Tourette’s syndrome is unknown.
No clear link has been established between symptoms of Tourette’s syndrome and cannabinoid sites or mechanism of action. Pimozide and haloperidol, two widely used treatments for Tourette’s syndrome, inhibit effects mediated by the neurotransmitter dopamine, whereas cannabinoids can increase dopamine release. (154,181) the physiological relevance, if any, of these two observations has not been established.
Clinical reports consist of four case histories indicating that cannabis use can reduce tics in Tourette’s patients.(75,163) In three of the four cases the investigators suggest that beneficial effects of cannabis might have been due to anxiety-reducing properties of cannabis rather than to a specific anti-tic effect.(163)
75. Hemming M, Yellowlees PM. 1993. Effective treatment of Tourette’s syndrome with marihuana. Journal of Psychopharmacology 7:389-391.
154. Rodriguez de Fonseca F, Carrera MRA, Navarro M, Koob G, Weiss F. 1997. Activation of corticotropin-releasing factor in the limbic system during cannabinoid withdrawal [see comments Science 1997., 276:1967-1968]. Science 276:2050-2054.
163. Sandyk R, Awerbuch G. 1988. Marihuana and Tourette’s syndrome. Journal of Clinical Psychopharmacology 8:444-445.