title: North American Prodrome Longitudinal Study: a collaborative multisite approach to prodromal schizophrenia research.
abstract: This article presents the rationale, design, and preliminary findings of the North American Prodrome Longitudinal Study (NAPLS), a collaborative, multisite investigation into the earliest phase of psychotic illness. We describe how 8 independently conceived research projects were integrated methodologically, how diagnostic reliability was achieved across sites on the Structured Interview for Prodromal Syndromes, and how baseline and follow-up data were aggregated for 888 at risk and comparison subjects. Data are presented describing the demographic, academic/work, and diagnostic characteristics of 3 relevant subgroups: persons at heightened clinical risk for psychosis, help-seeking comparison subjects, and nonpsychiatric controls. The NAPLS data set will be used to explore a series of questions related to prodromal psychosis, including the descriptive phenomenology of currently accepted diagnostic criteria, conversion rates over a 30-month period, predictors of psychosis onset and functional disability, and the impact of early treatment on the course of prodromal symptoms.
authors.affiliation: Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada. jean_addington@camh.net
authors.forename: Jean
authors.initials: J
authors.lastname: Addington
authors.forename: Kristin S
authors.initials: KS
authors.lastname: Cadenhead
authors.forename: Tyrone D
authors.initials: TD
authors.lastname: Cannon
authors.forename: Barbara
authors.initials: B
authors.lastname: Cornblatt
authors.forename: Thomas H
authors.initials: TH
authors.lastname: McGlashan
authors.forename: Diana O
authors.initials: DO
authors.lastname: Perkins
authors.forename: Larry J
authors.initials: LJ
authors.lastname: Seidman
authors.forename: Ming
authors.initials: M
authors.lastname: Tsuang
authors.forename: Elaine F
authors.initials: EF
authors.lastname: Walker
authors.forename: Scott W
authors.initials: SW
authors.lastname: Woods
authors.forename: Robert
authors.initials: R
authors.lastname: Heinssen
mesh_terms: D000293:Adolescent; D000328:Adult; D003299:Cooperative Behavior; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D015201:Meta-Analysis as Topic; D015337:Multicenter Studies as Topic; D009656:North America; D017063:Outcome Assessment, Health Care; D012106:Research; D012107:Research Design; D012307:Risk Factors; D012559:Schizophrenia / Q000175:diagnosis / Q000235:genetics / Q000517:prevention & control*; D012565:Schizophrenic Psychology; D012569:Schizotypal Personality Disorder / Q000175:diagnosis* / Q000523:psychology / Q000628:therapy