title: Effects of risperidone, amisulpride and nicotine on eye movement control and their modulation by schizotypy.
abstract: BACKGROUND
  The increasing demand to develop more efficient compounds to treat cognitive impairments in schizophrenia has led to the development of experimental model systems. One such model system combines the study of surrogate populations expressing high levels of schizotypy with oculomotor biomarkers.
  
  
  OBJECTIVE
  We aimed (1) to replicate oculomotor deficits in a psychometric schizotypy sample and (2) to investigate whether the expected deficits can be remedied by compounds shown to ameliorate impairments in schizophrenia.
  
  
  METHODS
  In this randomized double-blind, placebo-controlled study 233 healthy participants performed prosaccade (PS), antisaccade (AS) and smooth pursuit eye movement (SPEM) tasks after being randomly assigned to one of four drug groups (nicotine, risperidone, amisulpride, placebo). Participants were classified into medium- and high-schizotypy groups based on their scores on the Schizotypal Personality Questionnaire (SPQ, Raine (Schizophr Bull 17:555-564, 1991)).
  
  
  RESULTS
  AS error rate showed a main effect of Drug (p < 0.01), with nicotine improving performance, and a Drug by Schizotypy interaction (p = 0.04), indicating higher error rates in medium schizotypes (p = 0.01) but not high schizotypes under risperidone compared to placebo. High schizotypes had higher error rates than medium schizotypes under placebo (p = 0.03). There was a main effect of Drug for saccadic peak velocity and SPEM velocity gain (both p ≤ 0.01) indicating impaired performance with risperidone.
  
  
  CONCLUSIONS
  We replicate the observation of AS impairments in high schizotypy under placebo and show that nicotine enhances performance irrespective of group status. Caution should be exerted in applying this model as no beneficial effects of antipsychotics were seen in high schizotypes.
authors: Department of Neuroimaging, Institute of Psychiatry, King's College London, Centre for Neuroimaging Sciences, De Crespigny Park, P089, London, SE5 8AF, UK. anne.schmechtig@kcl.ac.uk
authors: Anne
authors: A
authors: Schmechtig
authors: Jane
authors: J
authors: Lees
authors: Lois
authors: L
authors: Grayson
authors: Kevin J
authors: KJ
authors: Craig
authors: Rukiya
authors: R
authors: Dadhiwala
authors: Gerard R
authors: GR
authors: Dawson
authors: J F William
authors: JF
authors: Deakin
authors: Colin T
authors: CT
authors: Dourish
authors: Ivan
authors: I
authors: Koychev
authors: Katrina
authors: K
authors: McMullen
authors: Ellen M
authors: EM
authors: Migo
authors: Charlotte
authors: C
authors: Perry
authors: Lawrence
authors: L
authors: Wilkinson
authors: Robin
authors: R
authors: Morris
authors: Steve C R
authors: SC
authors: Williams
authors: Ulrich
authors: U
authors: Ettinger
mesh_terms: D000293:Adolescent; D000328:Adult; D000077582:Amisulpride; D014150:Antipsychotic Agents / Q000494:pharmacology; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D009538:Nicotine / Q000494:pharmacology*; D011594:Psychometrics; D011698:Pursuit, Smooth / Q000187:drug effects; D018967:Risperidone / Q000494:pharmacology*; D012438:Saccades / Q000187:drug effects*; D012569:Schizotypal Personality Disorder / Q000175:diagnosis / Q000503:physiopathology*; D013469:Sulpiride / Q000031:analogs & derivatives* / Q000494:pharmacology; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents; D009538:Nicotine; D013469:Sulpiride; D000077582:Amisulpride; D018967:Risperidone