[Pineal melatonin in Tourette syndrome--can coloured light help?].

This article discusses David E. Comings' genetic standpoint that Tourette syndrome may be a general disinhibition syndrome that can be genetically caused by a decrease in brain serotonin/tryptophan content. The author proposes that the retina and the non-visual pathway, the inferior accessory optic tract, are involved. This hypothesis may serve to bridge the gap between the marker that Comings proposes and the visual field defects that J.M. Enoch discovered. The knowledge that both defective visual fields and serotonin/melatonin metabolism can change when stimulated by coloured light makes it appropriate to consider this kind of intervention as an alternative therapy.