Abstract
Background Anhedonia is a core symptom of multiple psychiatric disorders and has been associated with changes in brain structure. Genome-wide association studies suggest that anhedonia is heritable with a polygenic architecture but few studies have explored the association between genetic loading for anhedonia - indexed by polygenic risk scores for anhedonia (PRS-anhedonia) - and structural brain imaging phenotypes. We investigated how anhedonia and polygenic risk for anhedonia were associated with brain structure within the UK Biobank cohort.
Methods Brain measures (including total grey/white matter volumes, subcortical volumes, cortical thickness and white matter integrity) were analysed in relation to the self-reported anhedonia phenotype and PRS-anhedonia for 17,492 participants (8,506 males and 8,986 females; mean age = 62.81 years, SD = 7.43), using linear mixed models and including mediation analyses.
Results State anhedonia was significantly associated with smaller total grey matter volume (GMV), smaller volumes in thalamus and nucleus accumbens; as well as reduced cortical thickness within the paracentral gyrus, the opercular part of inferior frontal gyrus and the rostral anterior cingulate cortex. PRS-anhedonia was associated with reduced total GMV, increased total white matter volume and reduced white matter integrity; in addition to reduced cortical thickness within the parahippocampal cortex, the superior temporal gyrus and the insula cortex.
Conclusions Both the state anhedonia phenotype and PRS-anhedonia were associated with differences in multiple brain structures/areas, including within reward-related circuits. These differences may represent vulnerability markers for psychopathology across a range of psychiatric disorders.
Competing Interest Statement
The authors have declared no competing interest.
Funding Statement
XZ acknowledges financial support from China Scholarship Council. RJS is funded by UKRI Innovation-HDR-UK Fellowship(MR/S003061/1). DJS acknowledges support from a Lister Institute Prize Fellowship and an MRC Mental Health Data Pathfinder Award. JW is funded by DJS Lister Institute Prize Fellowship. LML is supported by the JMAS Sim Fellowship.
Author Declarations
I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.
Yes
The details of the IRB/oversight body that provided approval or exemption for the research described are given below:
This study was conducted under approval from the NHS National Research Ethics Service (UK Biobank approved applications #6553 and #17689).
All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.
Yes
I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).
Yes
I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.
Yes
Data Availability
All the data used in this manuscript comes from UK Biobank.