The invention relates to the use of low doses of (+)-a-dihydrotetrabenazine for the treatment of movement disorders, such as Tourette's syndrome. The invention provides (+)-a-Dihydrotetrabenazine or pharmaceutically acceptable salt thereof for use in a method of treating a movement disorder in a subject in need thereof, which method comprises steps of administering to the subject an initial daily dosage of (+)-a-dihydrotetrabenazine or pharmaceutically acceptable salt thereof, wherein the initial daily dosage is an amount of (+)-a-dihydrotetrabenazine or pharmaceutically acceptable salt thereof corresponding to from 0.5 mg to 5 mg of (+)-a-dihydrotetrabenazine free base, carrying out a clinical evaluation of the subject, either maintaining the initial daily dosage, increasing or reducing the dosage, or discontinuing the treatment. The method aims at reaching an optimum daily dosage.
