title: Developing psychosis and its risk states through the lens of schizotypy.
abstract: Starting from the early descriptions of Kraepelin and Bleuler, the construct of schizotypy was developed from observations of aberrations in nonpsychotic family members of schizophrenia patients. In contemporary diagnostic manuals, the positive symptoms of schizotypal personality disorder were included in the ultra high-risk (UHR) criteria 20 years ago, and nowadays are broadly employed in clinical early detection of psychosis. The schizotypy construct, now dissociated from strict familial risk, also informed research on the liability to develop any psychotic disorder, and in particular schizophrenia-spectrum disorders, even outside clinical settings. Against the historical background of schizotypy it is surprising that evidence from longitudinal studies linking schizotypy, UHR, and conversion to psychosis has only recently emerged; and it still remains unclear how schizotypy may be positioned in high-risk research. Following a comprehensive literature search, we review 18 prospective studies on 15 samples examining the evidence for a link between trait schizotypy and conversion to psychosis in 4 different types of samples: general population, clinical risk samples according to UHR and/or basic symptom criteria, genetic (familial) risk, and clinical samples at-risk for a nonpsychotic schizophrenia-spectrum diagnosis. These prospective studies underline the value of schizotypy in high-risk research, but also point to the lack of evidence needed to better define the position of the construct of schizotypy within a developmental psychopathology perspective of emerging psychosis and schizophrenia-spectrum disorders.
authors.affiliation: martin.debbane@unige.ch.
authors.forename: Martin
authors.initials: M
authors.lastname: Debbané
authors.affiliation: Office Médico-Pédagogique Research Unit, Department of Psychiatry, University of Geneva School of Medicine, Geneva, Switzerland;
authors.forename: Stephan
authors.initials: S
authors.lastname: Eliez
authors.affiliation: Developmental Clinical Psychology Research Unit, Faculty of Psychology and Educational Sciences, University of Geneva, Geneva, Switzerland; Office Médico-Pédagogique Research Unit, Department of Psychiatry, University of Geneva School of Medicine, Geneva, Switzerland;
authors.forename: Deborah
authors.initials: D
authors.lastname: Badoud
authors.affiliation: Department of Psychiatry, Service of General Psychiatry, Lausanne University Hospital (CHUV), Lausanne, Switzerland;
authors.forename: Philippe
authors.initials: P
authors.lastname: Conus
authors.affiliation: University Hospital of Child and Adolescent Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland.
authors.forename: Rahel
authors.initials: R
authors.lastname: Flückiger
authors.affiliation: University Hospital of Child and Adolescent Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland.
authors.forename: Frauke
authors.initials: F
authors.lastname: Schultze-Lutter
mesh_terms: D004198:Disease Susceptibility / Q000175:diagnosis*; D006801:Humans; D062706:Prodromal Symptoms; D011618:Psychotic Disorders / Q000175:diagnosis*; D012559:Schizophrenia / Q000175:diagnosis*; D012569:Schizotypal Personality Disorder / Q000175:diagnosis*
keywords: adolescence; basic symptoms; development; prodrome; schizophrenia