University of Worcester Worcester Research and Publications

Association Between Schizophrenia-Related Polygenic Liability and the Occurrence and Level of Mood-Incongruent Psychotic Symptoms in Bipolar Disorder

Allardyce, J., Leonenko, G., Hamshere, M.L., Pardiñas, A., Forty, L., Knott, Sarah, Gordon-Smith, Katherine ORCID:, Porteus, D., Haywood, C., Di Florio, A., Jones, Lisa ORCID:, McIntosh, A., Owen, M., Holmans, P., Walters, J., Craddock, N., Jones, I., O'Donovan, M.C. and Escott-Price, V. (2018) Association Between Schizophrenia-Related Polygenic Liability and the Occurrence and Level of Mood-Incongruent Psychotic Symptoms in Bipolar Disorder. JAMA Psychiatry, 75 (1). pp. 28-35. ISSN Print: 2168-622X Online: 2168-6238

[img] Text
Allardyce_A stratification study of bipolar disorder_accepted version post refereeing.docx - Accepted Version
Restricted to Repository staff only

Download (310kB) | Request a copy
Allardyce_A stratification study of bipolar disorder_accepted version post refereeing (1).pdf - Accepted Version

Download (420kB) | Preview
jamapsychiatry_Allardyce_2017_oi_170083.pdf - Published Version
Available under License Creative Commons Attribution.

Download (443kB) | Preview


Bipolar disorder (BD) overlaps schizophrenia in its clinical presentation and genetic liability. Alternative approaches to patient stratification beyond current diagnostic categories are needed to understand the underlying disease processes/mechanisms.
To investigate the relationship between common-variant liability for schizophrenia, indexed by polygenic risk scores (PRS) and psychotic presentations of BD, using clinical descriptions which consider both occurrence and level of mood-incongruent psychotic features.
Case-control design: using multinomial logistic regression, to estimate differential associations of PRS across categories of cases and controls.
Settings & Participants
4399 BD cases, 2966 (67%) female, mean age-at-interview 46 [sd 12] years, from the BD Research Network (BDRN) were included in the final analyses. For comparison genotypic data for 4976 schizophrenia cases and 9012 controls from the Type-1 diabetes genetics consortium and Generation Scotland were included.
Standardised PRS, calculated using alleles with an association p-value threshold < 0.05 in the second Psychiatric Genomics Consortium genome-wide association study of schizophrenia, adjusted for the first 10 population principal components and genotyping-platform.
Main outcome measure
Multinomial logit models estimated PRS associations with BD stratified by (1) Research Diagnostic Criteria (RDC) BD subtypes (2) Lifetime occurrence of psychosis.(3) Lifetime mood-incongruent psychotic features and (4) ordinal logistic regression examined PRS associations across levels of mood-incongruence. Ratings were derived from the Schedule for Clinical Assessment in Neuropsychiatry interview (SCAN) and the Bipolar Affective Disorder Dimension Scale (BADDS).
Across clinical phenotypes, there was an exposure-response gradient with the strongest PRS association for schizophrenia (RR=1.94, (95% C.I. 1.86, 2.01)), then schizoaffective BD (RR=1.37, (95% C.I. 1.22, 1.54)), BD I (RR= 1.30, (95% C.I. 1.24, 1.36)) and BD II (RR=1.04, (95% C.I. 0.97, 1.11)). Within BD cases, there was an effect gradient, indexed by the nature of psychosis, with prominent mood-incongruent psychotic features having the strongest association (RR=1.46, (95% C.I. 1.36, 1.57)), followed by mood-congruent psychosis (RR= 1.24, (95% C.I. 1.17, 1.33)) and lastly, BD cases with no history of psychosis (RR=1.09, (95% C.I. 1.04, 1.15)).
We show for the first time a polygenic-risk gradient, across schizophrenia and bipolar disorder, indexed by the occurrence and level of mood-incongruent psychotic symptoms.

Item Type: Article
Additional Information:

The online-first version of the full-text can be accessed via the Official URL.

Please note that a title of post-print has changed post acceptance date.

Uncontrolled Discrete Keywords: biploar, schizophrenia, psychotic symptoms, mood, mental health
Subjects: B Philosophy. Psychology. Religion > BF Psychology
R Medicine > RC Internal medicine > RC0321 Neuroscience. Biological psychiatry. Neuropsychiatry
Divisions: College of Health, Life and Environmental Sciences > School of Allied Health and Community
Related URLs:
Copyright Info: Open Access
Depositing User: Katherine Gordon-Smith
Date Deposited: 30 Nov 2017 09:55
Last Modified: 09 Jul 2020 11:45

Actions (login required)

View Item View Item
Worcester Research and Publications is powered by EPrints 3 which is developed by the School of Electronics and Computer Science at the University of Southampton. More information and software credits.