title: The Impact of a Cognitive-Behavioral Therapy on Event-Related Potentials in Patients with Tic Disorders or Body-Focused Repetitive Behaviors.
abstract: BACKGROUND
  Tic disorders (TD) are characterized by the presence of non-voluntary contractions of functionally related groups of skeletal muscles in one or multiple body parts. Patients with body-focused repetitive behaviors (BFRB) present frequent and repetitive behaviors, such as nail biting or hair pulling. TD and BFRB can be treated with a cognitive-behavioral therapy (CBT) that regulates the excessive amount of sensorimotor activation and muscular tension. Our CBT, which is called the cognitive-psychophysiological (CoPs) model, targets motor execution and inhibition, and it was reported to modify brain activity in TD. However, psychophysiological effects of therapy are still poorly understood in TD and BFRB patients. Our goals were to compare the event-related potentials (ERP) of TD and BFRB patients to control participants and to investigate the effects of the CoPs therapy on the P200, N200, and P300 components during a motor and a non-motor oddball task.
  
  
  METHODS
  Event-related potential components were compared in 26 TD patients, 27 BFRB patients, and 27 control participants. ERP were obtained from 63 EEG electrodes during two oddball tasks. In the non-motor task, participants had to count rare stimuli. In the motor task, participants had to respond with a left and right button press for rare and frequent stimuli, respectively. ERP measures were recorded before and after therapy in both patient groups.
  
  
  RESULTS
  CoPs therapy improved symptoms similarly in both clinical groups. Before therapy, TD and BFRB patients had reduced P300 oddball effect during the non-motor task, in comparison with controls participants. An increase in the P300 oddball effect was observed posttherapy. This increase was distributed over the whole cortex in BFRB patients, but localized in the parietal area in TD patients.
  
  
  CONCLUSIONS
  These results suggest a modification of neural processes following CoPs therapy in TD and BFRB patients. CoPs therapy seems to impact patients' attentional processes and context updating capacities in working memory (i.e., P300 component). Our results are consistent with a possible role of the prefrontal cortex and corpus callosum in mediating interhemispheric interference in TD.
authors.affiliation: Laboratoire de psychophysiologie cognitive et sociale, Montreal, QC, Canada; Centre de recherche de l'Institut universitaire en santé mentale de Montréal, Montreal, QC, Canada; Département de neurosciences, Faculté de médecine, Université de Montréal, Montreal, QC, Canada.
authors.forename: Simon
authors.initials: S
authors.lastname: Morand-Beaulieu
authors.affiliation: Centre de recherche de l'Institut universitaire en santé mentale de Montréal, Montreal, QC, Canada; Département de psychiatrie, Faculté de médecine, Université de Montréal, Montreal, QC, Canada.
authors.forename: Kieron P
authors.initials: KP
authors.lastname: O'Connor
authors.affiliation: Laboratoire de psychophysiologie cognitive et sociale, Montreal, QC, Canada; Centre de recherche de l'Institut universitaire en santé mentale de Montréal, Montreal, QC, Canada; Département de neurosciences, Faculté de médecine, Université de Montréal, Montreal, QC, Canada.
authors.forename: Maxime
authors.initials: M
authors.lastname: Richard
authors.affiliation: Laboratoire de psychophysiologie cognitive et sociale, Montreal, QC, Canada; Centre de recherche de l'Institut universitaire en santé mentale de Montréal, Montreal, QC, Canada.
authors.forename: Geneviève
authors.initials: G
authors.lastname: Sauvé
authors.affiliation: Centre de recherche de l'Institut universitaire en santé mentale de Montréal, Montreal, QC, Canada; Département de psychologie, Faculté des sciences humaines, Université du Québec à Montréal, Montreal, QC, Canada.
authors.forename: Julie B
authors.initials: JB
authors.lastname: Leclerc
authors.affiliation: Centre de recherche de l'Institut universitaire en santé mentale de Montréal, Montreal, QC, Canada; Département de stomatologie, Faculté de médecine dentaire, Université de Montréal, Montreal, QC, Canada.
authors.forename: Pierre J
authors.initials: PJ
authors.lastname: Blanchet
authors.affiliation: Laboratoire de psychophysiologie cognitive et sociale, Montreal, QC, Canada; Centre de recherche de l'Institut universitaire en santé mentale de Montréal, Montreal, QC, Canada; Département de psychiatrie, Faculté de médecine, Université de Montréal, Montreal, QC, Canada.
authors.forename: Marc E
authors.initials: ME
authors.lastname: Lavoie
keywords: Tourette syndrome; body-focused repetitive behaviors; cognitive–behavioral therapy; cognitive–psychophysiological therapy; electrophysiology; event-related potentials; habit disorder; tic disorders