PREVALENCE AND BURDEN OF ANHEDONIA IN KOREAN PATIENTS WITH MAJOR DEPRESSIVE DISORDER
Authors: Lee *Bolam , Kim Youngdoe , Eum Heekyung , Vandervoort Lawrence , Herr Keira , Lee Jung Goo 
Published: February 2025

Abstract

Background
According to an OECD report, approximately 4 in 10 people in South Korea suffer from a major depressive disorder (MDD) or depressed mood. The prevalence of MDD in Korea was 36.8%, the highest among OECD countries1. Although there have been numerous studies on depression, there is still an unmet need to characterize the various symptoms of MDD. In particular, anhedonia (ANH) is one of the most important symptoms of MDD according to the DSM-5 diagnostic criteria and is associated with poor prognosis, exacerbation, and inadequate treatment response in MDD2,3. However, the prevalence of ANH in depressed patients in Korea remains poorly understood. In this study, we aimed to investigate the prevalence of MDD with ANH in Korea and to determine the associated burden of disease.

Methods
From April to May 2023, 4496 adults in South Korea participated in a cross-sectional web- based survey. Respondents were classified as having moderate MDD if they had a Patient Health Questionnaire (PHQ)-9 score of 10 or higher, and as having MDD with ANH if they had a Snaith-Hamilton Pleasure Scale (SHAPS) score of 2 or higher4,5. Data from this study were analyzed for sociodemographic and health-related quality of life (HRQoL) using bivariate analysis. All results were age- and sex- weighted using United Nations population estimates6. Multiple regression models were also used to examine the adjusted effect of ANH in the MDD sample.

Results
Of the 4496 participants, 1112 (24.8%) reported moderate or severe MDD, of whom 447 (9.9%) had a physician diagnosis of depression and confirmed to present MDD per the definition in our study. In addition, 275 (61.5% of MDD patients) MDD-ANH respondents were identified, and their rates of depression severity (moderate n=130, 47.3%; severe n=48, 17.5%) were similar to the overall MDD sample. However, the duration of MDD since diagnosis was significantly longer for MDD-ANH compared to non-ANH (7.71 vs. 5.74 years; p=0.0206). The percentage currently taking antidepressants was significantly lower in MDD-ANH compared to MDD non-ANH (47.6% vs 66.83%; p=0.0032). For HRQoL outcomes, after adjusting for RAND Mental Health Composite (RAND MHC)7 and EQ-VAS8 scores, the MDD-ANH group had worse health status compared to the non-ANH group (-0.27 and -1.138; p=0.005 and p&lt;0.001, respectively). In particular, presenteeism (the proportion of people whose health affected their work in the last 7 days) was statistically higher in MDD-ANH compared to non-MDD-ANH (0.713; p=0.033).

Discussion And Conclusion
This is the first epidemiological study showing that 61.5% of Korean MDD patients had comorbid anhedonia. The MDD-ANH group had a longer duration of MDD but a lower percentage of medication use than the non-ANH group implying medical unmet needs. In addition, the MDD-ANH group had poorer MDD-related quality of life (HRQoL). In particular, analyses of work productivity indicated that there may be high presenteeism, which is a potential economic burden. These findings suggest that the clinical characteristics of the MDD-ANH group differ from those of the MDD- non-ANH group and highlight the importance of monitoring anhedonia symptoms to optimize MDD treatment.

References
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