BACKGROUND: The purpose of this study was to investigate whether the three disorders in the bipolar spectrum, Bipolar I disorder, Bipolar II disorder and Cyclothymia, are various expressions of an underlying genetic commonality. METHOD: A sample consisting of same-sexed mono (MZ)- and dizygotic (DZ) twins were identified using hospital and outpatient registers (N=303). DSM-III-R criteria were assessed by personal interviews. Cross tabulations were used to compare concordance rates for different definitions of the bipolar spectrum. Correlations in liability and estimation of the heritability (h) with biometrical model fitting were performed. RESULTS: Concordance rates were higher among MZ- than DZ pairs for all the single diagnoses and main combinations of diagnoses. Cross-concordance between different diagnoses was observed. The heritability of Bipolar I was .73, of Bipolar I+II .77 and of Bipolar I+II+Cyclothymia .71. LIMITATION: Probands were not sampled from the general population. Most often the same person interviewed both twins in a pair. The statistical power was restricted in some sub-analyses. CONCLUSION: The 'Bipolar Spectrum' category consisting of Bipolar I disorder, Bipolar II disorder and Cyclothymia constitute one entity with high heritability without detectable shared family environmental effects. Future genetic and clinical work might consider that all variants of the bipolar spectrum are an expression of one underlying genetic liability.
BACKGROUND: The purpose of this study was to investigate whether the three disorders in the bipolar spectrum, Bipolar I disorder, Bipolar II disorder and Cyclothymia, are various expressions of an underlying genetic commonality. METHOD: A sample consisting of same-sexed mono (MZ)- and dizygotic (DZ) twins were identified using hospital and outpatient registers (N=303). DSM-III-R criteria were assessed by personal interviews. Cross tabulations were used to compare concordance rates for different definitions of the bipolar spectrum. Correlations in liability and estimation of the heritability (h) with biometrical model fitting were performed. RESULTS: Concordance rates were higher among MZ- than DZ pairs for all the single diagnoses and main combinations of diagnoses. Cross-concordance between different diagnoses was observed. The heritability of Bipolar I was .73, of Bipolar I+II .77 and of Bipolar I+II+Cyclothymia .71. LIMITATION: Probands were not sampled from the general population. Most often the same person interviewed both twins in a pair. The statistical power was restricted in some sub-analyses. CONCLUSION: The 'Bipolar Spectrum' category consisting of Bipolar I disorder, Bipolar II disorder and Cyclothymia constitute one entity with high heritability without detectable shared family environmental effects. Future genetic and clinical work might consider that all variants of the bipolar spectrum are an expression of one underlying genetic liability.
Authors: Suzanne Gonzalez; Chun Xu; Mercedes Ramirez; Juan Zavala; Regina Armas; Salvador A Contreras; Javier Contreras; Albana Dassori; Robin J Leach; Deborah Flores; Alvaro Jerez; Henriette Raventós; Alfonso Ontiveros; Humberto Nicolini; Michael Escamilla Journal: Bipolar Disord Date: 2013-03 Impact factor: 6.744
Authors: D P Howrigan; N M Laird; J W Smoller; B Devlin; M B McQueen Journal: Am J Med Genet B Neuropsychiatr Genet Date: 2011-04-07 Impact factor: 3.568
Authors: Liping Hou; Sarah E Bergen; Nirmala Akula; Jie Song; Christina M Hultman; Mikael Landén; Mazda Adli; Martin Alda; Raffaella Ardau; Bárbara Arias; Jean-Michel Aubry; Lena Backlund; Judith A Badner; Thomas B Barrett; Michael Bauer; Bernhard T Baune; Frank Bellivier; Antonio Benabarre; Susanne Bengesser; Wade H Berrettini; Abesh Kumar Bhattacharjee; Joanna M Biernacka; Armin Birner; Cinnamon S Bloss; Clara Brichant-Petitjean; Elise T Bui; William Byerley; Pablo Cervantes; Caterina Chillotti; Sven Cichon; Francesc Colom; William Coryell; David W Craig; Cristiana Cruceanu; Piotr M Czerski; Tony Davis; Alexandre Dayer; Franziska Degenhardt; Maria Del Zompo; J Raymond DePaulo; Howard J Edenberg; Bruno Étain; Peter Falkai; Tatiana Foroud; Andreas J Forstner; Louise Frisén; Mark A Frye; Janice M Fullerton; Sébastien Gard; Julie S Garnham; Elliot S Gershon; Fernando S Goes; Tiffany A Greenwood; Maria Grigoroiu-Serbanescu; Joanna Hauser; Urs Heilbronner; Stefanie Heilmann-Heimbach; Stefan Herms; Maria Hipolito; Shashi Hitturlingappa; Per Hoffmann; Andrea Hofmann; Stephane Jamain; Esther Jiménez; Jean-Pierre Kahn; Layla Kassem; John R Kelsoe; Sarah Kittel-Schneider; Sebastian Kliwicki; Daniel L Koller; Barbara König; Nina Lackner; Gonzalo Laje; Maren Lang; Catharina Lavebratt; William B Lawson; Marion Leboyer; Susan G Leckband; Chunyu Liu; Anna Maaser; Pamela B Mahon; Wolfgang Maier; Mario Maj; Mirko Manchia; Lina Martinsson; Michael J McCarthy; Susan L McElroy; Melvin G McInnis; Rebecca McKinney; Philip B Mitchell; Marina Mitjans; Francis M Mondimore; Palmiero Monteleone; Thomas W Mühleisen; Caroline M Nievergelt; Markus M Nöthen; Tomas Novák; John I Nurnberger; Evaristus A Nwulia; Urban Ösby; Andrea Pfennig; James B Potash; Peter Propping; Andreas Reif; Eva Reininghaus; John Rice; Marcella Rietschel; Guy A Rouleau; Janusz K Rybakowski; Martin Schalling; William A Scheftner; Peter R Schofield; Nicholas J Schork; Thomas G Schulze; Johannes Schumacher; Barbara W Schweizer; Giovanni Severino; Tatyana Shekhtman; Paul D Shilling; Christian Simhandl; Claire M Slaney; Erin N Smith; Alessio Squassina; Thomas Stamm; Pavla Stopkova; Fabian Streit; Jana Strohmaier; Szabolcs Szelinger; Sarah K Tighe; Alfonso Tortorella; Gustavo Turecki; Eduard Vieta; Julia Volkert; Stephanie H Witt; Adam Wright; Peter P Zandi; Peng Zhang; Sebastian Zollner; Francis J McMahon Journal: Hum Mol Genet Date: 2016-06-21 Impact factor: 6.150
Authors: Richard C McEachin; Nancy L Saccone; Scott F Saccone; Yelena D Kleyman-Smith; Tiara Kar; Rajesh K Kare; Alex S Ade; Maureen A Sartor; James D Cavalcoli; Melvin G McInnis Journal: BMC Med Genet Date: 2010-01-26 Impact factor: 2.103