title: A taxometric analysis of schizophrenia symptoms.
abstract: Specific disorders within the psychosis syndrome have been proposed although no definitive validation of subtypes has been achieved. If there are subtypes of psychosis, latent discontinuity between clinical descriptors should be found. We applied for the first time taxometric analysis on characteristic schizophrenia symptoms. The sample consisted of 660 inpatients with an acute psychotic episode. Computed scores of the clinical dimensions included in the three-syndrome model of schizophrenia symptomatology were used as clinical descriptors or latent variables to be analyzed. Two taxometric analyses were used (MAXCOV and MAMBAC). Discrepancies between observed covariance curves and between the estimated base rates of indicators did not support a taxonic conjecture within psychosis based on the severity of 'Psychosis', 'Negative' and 'Disorganization' dimensions scores, which were used as indicators. However, no appropriate solution could be reached because the three clinical indicators of schizophrenia symptomatology used in this study showed a lack of consistency. The lack of a taxonic structure with symptomatological domains of psychosis suggested the existence of a dimensional solution for schizophrenia symptomatology within psychoses.
authors.affiliation: Psychiatric Unit of Virgen del Camino Hospital, C/ Irunlarrea 4, Pamplona E-31008, Spain. mcuestaz@cfnavarra.es
authors.forename: Manuel J
authors.initials: MJ
authors.lastname: Cuesta
authors.forename: M Dolores
authors.initials: MD
authors.lastname: Ugarte
authors.forename: Tomas
authors.initials: T
authors.lastname: Goicoa
authors.forename: Sandra
authors.initials: S
authors.lastname: Eraso
authors.forename: Victor
authors.initials: V
authors.lastname: Peralta
mesh_terms: D000328:Adult; D000339:Affect; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D008297:Male; D011618:Psychotic Disorders / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology; D012559:Schizophrenia / Q000145:classification* / Q000175:diagnosis* / Q000453:epidemiology; D012565:Schizophrenic Psychology; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires