title: A validation of cognitive biomarkers for the early identification of cognitive enhancing agents in schizotypy: a three-center double-blind placebo-controlled study.
abstract: A number of compounds aimed at improving cognition in schizophrenia have failed to demonstrate efficacy in Phase 2 clinical trials. Translational studies using biomarkers in surrogate populations, such as schizotypy, could be used to assess the efficacy of novel compounds. In this study, we aimed to validate the sensitivity and inter-site reliability of cognitive biomarkers (working memory (N-back), spatial working memory (SWM) and verbal fluency (VF) tasks) to detect the schizotypy phenotype and its reversal by psychotropic drugs. Healthy volunteers scoring high or average on a schizotypal personality measure (122 in each group) were randomized to receive a single dose of risperidone, amisulpride, nicotine or placebo in a double-blind, between-subject design. We found evidence for a poorer performance on N-back and VF tasks in the high schizotypy group, replicating previous research. This effect was counteracted by amisulpride on N-back: it improved working memory in high schizotypy group but impaired the controls. A similar pattern was seen in SWM and VF. We interpret this finding in the light of the dopamine enhancing action of amisulpride when given in low doses. In contrast, risperidone impaired both groups and nicotine had a beneficial effect for the low baseline performers only. These effects were consistent across sites. These data demonstrates the utility of biomarkers in detecting the effect of schizotypy and its reversal by drugs that enhance dopamine and cholinergic function. Studies using similar design could help the early assessment of potential of compounds designed to improve cognition in schizophrenia.
authors.affiliation: Neuroscience and Psychiatry Unit, School of Community Based Medicine, The University of Manchester, Manchester M13 9PT, UK. ivan.koychev@doctors.org.uk
authors.forename: Ivan
authors.initials: I
authors.lastname: Koychev
authors.forename: Katrina
authors.initials: K
authors.lastname: McMullen
authors.forename: Jane
authors.initials: J
authors.lastname: Lees
authors.forename: Rukiya
authors.initials: R
authors.lastname: Dadhiwala
authors.forename: Lois
authors.initials: L
authors.lastname: Grayson
authors.forename: Charlotte
authors.initials: C
authors.lastname: Perry
authors.forename: Anne
authors.initials: A
authors.lastname: Schmechtig
authors.forename: James
authors.initials: J
authors.lastname: Walters
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Craig
authors.forename: Gerard R
authors.initials: GR
authors.lastname: Dawson
authors.forename: Colin T
authors.initials: CT
authors.lastname: Dourish
authors.forename: Ulrich
authors.initials: U
authors.lastname: Ettinger
authors.forename: Lawrence
authors.initials: L
authors.lastname: Wilkinson
authors.forename: Steven
authors.initials: S
authors.lastname: Williams
authors.forename: John Francis William
authors.initials: JF
authors.lastname: Deakin
authors.forename: Emma
authors.initials: E
authors.lastname: Barkus
mesh_terms: D000328:Adult; D000077582:Amisulpride; D000704:Analysis of Variance; D015415:Biomarkers / Q000378:metabolism; D003072:Cognition Disorders / Q000175:diagnosis* / Q000188:drug therapy* / Q000209:etiology; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000187:drug effects; D009483:Neuropsychological Tests; D018697:Nootropic Agents / Q000627:therapeutic use*; D010555:Personality Inventory; D015203:Reproducibility of Results; D018967:Risperidone / Q000627:therapeutic use*; D012569:Schizotypal Personality Disorder / Q000150:complications; D013469:Sulpiride / Q000031:analogs & derivatives* / Q000627:therapeutic use; D011795:Surveys and Questionnaires; D006113:United Kingdom; D014705:Verbal Behavior / Q000187:drug effects; D055815:Young Adult
chemical_list: D015415:Biomarkers; D018697:Nootropic Agents; D013469:Sulpiride; D000077582:Amisulpride; D018967:Risperidone