J
Jan Olav Johannessen
Researcher at Stavanger University Hospital
Publications - 137
Citations - 5786
Jan Olav Johannessen is an academic researcher from Stavanger University Hospital. The author has contributed to research in topics: First episode & Psychosis. The author has an hindex of 38, co-authored 129 publications receiving 5292 citations. Previous affiliations of Jan Olav Johannessen include University of Bergen & University of Oslo.
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Journal ArticleDOI
Reducing the duration of untreated first-episode psychosis: effects on clinical presentation.
Ingrid Melle,Tor K. Larsen,Ulrik Haahr,Svein Friis,Jan Olav Johannessen,Stein Opjordsmoen,Erik Simonsen,Bjørn Rishovd Rund,Per Vaglum,Thomas H. McGlashan +9 more
TL;DR: It is possible to reduce the DUP for first-episode patients in a defined health care area through the introduction of an early detection (ED) program, compared with parallel health care areas without an ED program (No-ED).
Journal ArticleDOI
Early Detection and Intervention With Schizophrenia: Rationale
TL;DR: The evidence to date does not demonstrate that early intervention with known treatments can change the natural history of schizophrenia, but it is suggestive enough (for both biological and psychosocial treatment) to support further investigation.
Journal ArticleDOI
International clinical practice guidelines for early psychosis
Jean Addington,G.P. Amminger,A. Barbato,Stanley V. Catts,Eric Y.H. Chen,S. Chhim,Suyinn Chong,J. Cullberg,John F. Edwards,L. Grosso,Mario Rodrigues Louzã,M. Hambrecht,Matcheri S. Keshavan,Jan Olav Johannessen,D. L. Johnson,Shôn Lewis,Jeffrey A. Lieberman,W. MacEwan,Ashok K. Malla,R. May,Thomas H. McGlashan,Patrick D. McGorry,M. G. Merlo,Merete Nordentoft,S. Nightingale,Diana O. Perkins,R. Thara,K. Yamamoto,Alison R. Yung +28 more
TL;DR: These international clinical practice guidelines were developed with detailed input from 29 invited international consultants, who provided content as well as detailed feedback on draft versions, to provide practical guidance to clinicians and researchers.
Journal ArticleDOI
Early detection strategies for untreated first-episode psychosis
Jan Olav Johannessen,Thomas H. McGlashan,Tor K. Larsen,Marthe Horneland,Inge Joa,Sigurd Mardal,Rune Kvebæk,Svein Friis,Ingrid Melle,Stein Opjordsmoen,Erik Simonsen,Haahr Ulrik,Per Vaglum +12 more
TL;DR: The study's major independent intervention variable is described, i.e. a comprehensive education and detection system to change DUP in first onset psychosis, which appears to be effective and to influence directly the community's help-seeking behaviour.
Journal ArticleDOI
Premorbid functioning versus duration of untreated psychosis in 1 year outcome in first-episode psychosis.
TL;DR: The findings strengthen the rationale for establishing health service programs for early detection and treatment of first-onset psychosis and to a limited degree premorbid functioning and DUP interact, but DUP has an independent influence on outcome.