title: Assessing sub-clinical psychosis phenotypes in the general population--a multidimensional approach.
abstract: Several studies have demonstrated that expression of a psychosis phenotype can be observed below the threshold of its clinical detection. To date, however, no conceptual certainty has been reported for the validity and reliability of sub-clinical psychosis. Our main objectives were to assess the prevalence rates and severity of various psychosis symptoms in a representative community sample. Furthermore, we wanted to analyze which latent factors are depicted by several currently used psychosis questionnaires. We also examined how those latent factors for sub-clinical psychosis are linked to psychosocial factors, normal personality traits, and coping abilities related to chronic stress. Most of the eight subscales from the Paranoia Checklist and the Structured Interview for Assessing Perceptual Anomalies had a very similar type of distribution, i.e., an inverse Gaussian (Wald) distribution. This supported the notion of a continuity of psychotic symptoms, which we would expect to find for continuously distributed symptoms within the general population. Sub-clinical psychosis can be reduced to two different factors - one representing odd beliefs about the world and odd behavior, and the other one representing anomalous perceptions (such as hallucinations). Persons with odd beliefs and behavior are under greater burden and more susceptible to psychosocial risks than are persons with anomalous perceptions. These sub-clinical psychosis syndromes are also related to stable personality traits. In conclusion, we obtained strong support for the notion that there is no natural cut-off separating psychotic illness from good health. Sub-clinical psychosis of any kind is not trivial because it is associated with various types of social disability.
authors.affiliation: Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Switzerland; Institute of Psychiatry, Laboratory of Neuroscience (LIM 27), University of Sao Paulo, Brazil; Zurich Programme for Sustainable Development of Mental Health Services, Zurich, Switzerland. Electronic address: wulf.roessler@uzh.ch.
authors.forename: Wulf
authors.initials: W
authors.lastname: Rössler
authors.affiliation: Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Switzerland; Zurich Programme for Sustainable Development of Mental Health Services, Zurich, Switzerland.
authors.forename: Vladeta
authors.initials: V
authors.lastname: Ajdacic-Gross
authors.affiliation: Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Switzerland; Zurich Programme for Sustainable Development of Mental Health Services, Zurich, Switzerland.
authors.forename: Mario
authors.initials: M
authors.lastname: Müller
authors.affiliation: Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Switzerland; Zurich Programme for Sustainable Development of Mental Health Services, Zurich, Switzerland.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Rodgers
authors.affiliation: Translational Neuromodeling Unit, Institute for Biomedical Engineering, University of Zurich & ETH, Zurich, Switzerland.
authors.forename: Helene
authors.initials: H
authors.lastname: Haker
authors.affiliation: Zurich Programme for Sustainable Development of Mental Health Services, Zurich, Switzerland; Department of Applied Psychology, Zurich University of Applied Sciences (ZHAW), Zurich, Switzerland.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Hengartner
mesh_terms: D000328:Adult; D000367:Age Factors; D005260:Female; D006801:Humans; D008297:Male; D010551:Personality; D010641:Phenotype; D025341:Principal Component Analysis; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D012111:Residence Characteristics; D012307:Risk Factors; D057566:Self Report; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Community sample; Epidemiology; Proneness to psychosis; Psychotic-like experiences; Risk factors; Schizotypy; Sub-clinical psychosis