TY  - JOUR
AU  - Guzman-Parra, Jose
AU  - Streit, Fabian
AU  - Forstner, Andreas J.
AU  - Strohmaier, Jana
AU  - González, Maria José
AU  - Gil Flores, Susana
AU  - Cabaleiro Fabeiro, Francisco J.
AU  - del Río Noriega, Francisco
AU  - Perez Perez, Fermin
AU  - Haro González, Jesus
AU  - Orozco Diaz, Guillermo
AU  - de Diego-Otero, Yolanda
AU  - Moreno-Kustner, Berta
AU  - Auburger, Georg
AU  - Degenhardt, Franziska
AU  - Heilmann-Heimbach, Stefanie
AU  - Herms, Stefan
AU  - Hoffmann, Per
AU  - Frank, Josef
AU  - Foo, Jerome C.
AU  - Sirignano, Lea
AU  - Witt, Stephanie H.
AU  - Cichon, Sven
AU  - Rivas, Fabio
AU  - Mayoral, Fermín
AU  - Nöthen, Markus M.
AU  - Andlauer, Till F. M.
AU  - Rietschel, Marcella
TI  - Clinical and genetic differences between bipolar disorder type 1 and 2 in multiplex families
JO  - Translational Psychiatry
VL  - 11
IS  - 1
SN  - 2158-3188
CY  - London
PB  - Nature Publishing Group
M1  - FZJ-2021-02936
SP  - 31
PY  - 2021
AB  - The two major subtypes of bipolar disorder (BD), BD-I and BD-II, are distinguished based on the presence of manic or hypomanic episodes. Historically, BD-II was perceived as a less severe form of BD-I. Recent research has challenged this concept of a severity continuum. Studies in large samples of unrelated patients have described clinical and genetic differences between the subtypes. Besides an increased schizophrenia polygenic risk load in BD-I, these studies also observed an increased depression risk load in BD-II patients. The present study assessed whether such clinical and genetic differences are also found in BD patients from multiplex families, which exhibit reduced genetic and environmental heterogeneity. Comparing 252 BD-I and 75 BD-II patients from the Andalusian Bipolar Family (ABiF) study, the clinical course, symptoms during depressive and manic episodes, and psychiatric comorbidities were analyzed. Furthermore, polygenic risk scores (PRS) for BD, schizophrenia, and depression were assessed. BD-I patients not only suffered from more severe symptoms during manic episodes but also more frequently showed incapacity during depressive episodes. A higher BD PRS was significantly associated with suicidal ideation. Moreover, BD-I cases exhibited lower depression PRS. In line with a severity continuum from BD-II to BD-I, our results link BD-I to a more pronounced clinical presentation in both mania and depression and indicate that the polygenic risk load of BD predisposes to more severe disorder characteristics. Nevertheless, our results suggest that the genetic risk burden for depression also shapes disorder presentation and increases the likelihood of BD-II subtype development.
LB  - PUB:(DE-HGF)16
C6  - 33431802
UR  - <Go to ISI:>//WOS:000609884900005
DO  - DOI:10.1038/s41398-020-01146-0
UR  - https://juser.fz-juelich.de/record/893926
ER  -