Objective To investigate the prevalence and clinical correlates of video polysomnography (vPSG)-confirmed rapid eye movement sleep behaviour disorder (RBD) in patients with major depressive disorder (MDD).
Methods This is a clinic-based two-phase epidemiological study. In phase 1, patients with MDD were screened by a validated questionnaire, RBD Questionnaire-Hong Kong (RBDQ-HK). In phase 2, a subsample of both the screen-positive (RBDQ-HK >20) and screen–negative patients with MDD underwent further clinical and sleep assessment (vPSG) to confirm the diagnosis of RBD (MDD+RBD). Poststratification weighting method was used to estimate the prevalence of MDD+RBD. The total likelihood ratio and the probability of prodromal Parkinson’s disease (PD) were calculated from prodromal markers and risk factors, as per the Movement Disorder Society research criteria.
Results A total of 455 patients with MDD were screened (median age (IQR)=52.66 (15.35) years, 77.58% woman, 43.74% positive). Eighty-one patients underwent vPSG and 12 of them were confirmed MDD+RBD. The prevalence of MDD+RBD was estimated to be 8.77% (95% CI: 4.33% to 16.93%), with possibly male predominance. MDD+RBD were associated with colour vision and olfaction deficit and a higher probability for prodromal PD.
Conclusions Almost 9% of patients with MDD in the psychiatric outpatient clinic has vPSG-confirmed RBD. Comorbid MDD+RBD may represent a subtype of MDD with underlying α-synucleinopathy neurodegeneration. Systematic screening of RBD symptoms and necessity of vPSG confirmation should be highlighted for capturing this MDD subtype with a view to enhance personalised treatment and future neuroprotection to prevent neurodegeneration.
- sleep disorders
Data availability statement
Data are available upon reasonable request.
Statistics from Altmetric.com
JW and SWHC contributed equally.
Presented at The preliminary analysis results were presented in the 13th Symposium of the International REM Sleep Behavior Disorder Study Group (IRBDSG) in Copenhagen, Denmark, 3–5 October 2019.
Contributors JW and SWHC are joint first authors as they contributed equally to this study in data analysis and manuscript drafting. YKW, SPL and JZ conceived the idea for conducting this study and applied for the funding. SPL, NYC, MWMY, JCTT, JWYC, JW, SWHC, MMSC and BH contributed to the subject recruitment and data collection. YKW, YL and JZ supervised the data cleansing and analysis. VM provided his expertise in neurological assessments and clinical referral to neurologists where applicable. All authors critically reviewed this manuscript. All authors gave final approval for the submitted article and take responsibility for the accuracy and integrity of this work. YKW is responsible for the overall content as the guarantor.
Funding This study was supported by the General Research Fund (Reference No.: 14117915) of the Research Grant Council.
Competing interests JW and BH were supported by the Faculty Postdoctoral Fellowship Scheme of the Chinese University of Hong Kong. The University reimbursed their registration fee and airfare for attending international academic conferences in 2019. YL was supported by the Postdoctoral Fellowship in Clinical Neurosciences of the Chinese University of Hong Kong. JWYC received personal fees from Eisai for joining an insomnia expert forum. YKW received personal fees from Eisai for lecture and travel support from Lundbeck HK, which are outside the submitted work.
Provenance and peer review Not commissioned; externally peer reviewed.
Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.