Abstract: The present invention relates to the reduction of the side-effects induced by tetrabenazine or other inhibitors of vesicular monoamine transporter (VMAT), in the treatment of central nervous system disorders such as Huntington's disease, L-DOPA-induced dyskinesias in Parkinson's disease, Tourette's syndrome or tardive dyskinesia. The invention comprises administering to a patient in need thereof an effective amount of activates selective serotonin 5-HT1A receptors agonist, whereby the side-effects of depression or Parkinsonism induced by tetrabenazine or other VMAT inhibitors are minimized.