https://ir.ymlib.yonsei.ac.kr/handle/22282913/168928 2026-05-15T08:17:37Z https://ir.ymlib.yonsei.ac.kr/handle/22282913/211871 Title: Impact of social media use in static and dynamic functional network connectivity of social anxiety disorder Authors: Kim, Hesun Erin; Kim, Byung-Hoon; Cho, Yesol; Ko, Yujin; Kim, Jae-Jin Abstract: Although social media use patterns are related to social anxiety disorder (SAD), their modulatory relationship with functional network connectivity (FNC) change remains unexplored. This study aims to address this question by utilizing static and dynamic FNC analyses. Using resting-state fMRI data from 45 SAD patients and 43 healthy controls (HC) across two acquisition timepoints (baseline, 2-month follow-up), we examined static and dynamic FNC. Standard region-of-interest (ROI)-to-ROI analysis was performed for static FNC. Dynamic FNC was analyzed using sliding-window and kmeans clustering approach. Social media usage was differentiated between messaging (MSG) and social platform (SP) across four time-of-day segments. Influences of digital social behavior were assessed through correlation analysis. Patients showed decreased static connectivity within cognitive control networks, particularly involving the default mode network. Dynamic FNC analysis identified four brain states, with SAD showing altered temporal dynamics. Specifically, patients exhibited abnormalities in the temporal properties of State 1, characterized as an internally focused state linked to self-referential processing. Lowered State 1 occurrence at follow-up was associated with higher social media use-MSG use in HC and SP use in SAD. Greater SP use was related to increased engagements of an externally vigilant state (State 3) in SAD. Aberrant temporal properties in SAD illustrate difficulties disengaging from maladaptive self-referential processing and a propensity toward heightened sensory vigilance. Furthermore, social media use, particularly content-based SP, may modulate brain dynamics related to introspection and external processing among patients. The findings underscore comprehensive neurobiological underpinnings of SAD and impacts of digital social behavior. 2026-08-01T00:00:00Z https://ir.ymlib.yonsei.ac.kr/handle/22282913/212113 Title: Network analysis of item-level neuroticism in recurrent major depression among Korean women Authors: Yu, Hyeona; Park, Jungkyu; Rhee, Sang Jin; Min, Sooyeon; Song, Yoojin; Lee, Heon-Jeong; Won, Seunghee; Lee, Kyu Young; Ko, YoungHoon; Choi, KwangYeon; Jo, Young Tak; Cho, Sung Joon; Lee, Hwayoung; Kang, Won Sub; Moon, Seok Woo; Lee, Yunna; Seo, Junho; Kim, Ga Eun; Kim, Se Joo; Ko, MinSoo; Yun, Ji-ae; Cheon, Eun-Jin; Moon, Eunsoo; Choi, Mal Rye; Ha, Tae Hyon; Lee, Jakyung; Kim, Jee Wook; Flint, Jonathan; Ahn, Yong Min; Myung, Woojae; Kendler, Kenneth S. Abstract: Background: Neuroticism is a core personality trait strongly associated with Major Depressive Disorder (MDD), influencing both its onset and recurrence, and suggesting a persistent vulnerability to depression. Methods: The study included 2997 women with recurrent MDD and 3046 female controls. Neuroticism was assessed using the Neuroticism scale of the Eysenck Personality Questionnaire. Networks were estimated using the Ising model, community structures derived through Exploratory Graph Analysis, and stability tested via bootstrapping. Network Comparison Tests evaluated structural and connectivity differences between groups, with sensitivity analyses excluding zero-scoring participants. Results: Both groups exhibited a four-community configuration, including tension/agitation, hyperarousal and sleep disturbance, interpersonal sensitivity, and cognitive distress. "Being sensitive" emerged as the most central node, strongly linked to insomnia. Although the network structure was similar, the MDD group showed signif-icantly lower global strength. Bootstrapped analyses confirmed the stability of centrality indices. No significant network differences were found within the MDD group based on episode frequency, melancholia, or suicide risk. Sensitivity analyses showed that excluding zero-scoring controls led to lower global strength in the control group. Limitations: The study focused exclusively on women, which limits the generalizability of the findings to all genders, and relied on self-report questionnaires, which may introduce biases. Conclusion: Neuroticism exhibited a stable structure in both groups, but global connectivity was lower in the MDD group. "Being sensitive" emerged as the central node, suggesting its potential as a target for intervention. 2026-08-01T00:00:00Z https://ir.ymlib.yonsei.ac.kr/handle/22282913/211533 Title: Extraversion as a mediator of genetic effects on positive affect in Korean adolescent girls Authors: Lee, Sung-Ha; Lim, Hojun; Kim, Kipoong; Youm, Yoosik; Kim, Eunjoo Abstract: Recent genomic findings provide evidence for genetic variation underlying individual differences in well-being, yet the mechanisms through which genetic factors translate into emotional experiences remain poorly understood. Accordingly, this study aims to examine whether a polygenic score (PGS) correlates with positive emotions, thereby addressing the genetic basis of emotional well-being. Moreover, based on prior evidence linking extraversion to both genetic predispositions and positive emotions, we further examined whether extraversion mediates this relationship. Using the PGS for happiness derived from a recent genome-wide association study conducted with Korean populations, we assessed the genetic basis of happiness in relation to positive affect among Korean adolescent girls (N = 211, Mean age = 15.8 yrs (SD = 0.3 yrs)). Mediation analysis revealed a significant indirect effect of happiness PGS on positive affect through extraversion, but no significant direct effect. These findings suggest that genetic influences on well-being exert their effects through personality traits rather than directly modulating emotional states, underscoring the importance of considering mediating psychological constructs in genetic models of well-being. 2026-07-01T00:00:00Z https://ir.ymlib.yonsei.ac.kr/handle/22282913/211762 Title: Culturally adapted digital cognitive behavioral therapy for insomnia in South Korea-a double-blind randomized controlled trial Authors: Kabbani, Abdallah; Passler, Mona; Park, Kyungmee; Lee, Eun; Lee, Yujin; Jansen, Marc; Moon, Daa Un Abstract: Culturally adapted digital cognitive behavioral therapy for insomnia (dCBT-I) has the potential to enhance engagement and treatment outcomes, yet its efficacy compared to patient education (PE) remains understudied. This multicenter, double-blind, randomized controlled trial evaluated dCBT-I versus a PE application in individuals with chronic insomnia in South Korea. The primary outcome was Insomnia Severity Index (ISI) scores. Secondary and exploratory outcomes included sleep diary measures, self-reported scales assessing sleep quality, maladaptive sleep-related beliefs, daytime sleepiness, anxiety, and depressive symptoms. Of 52 participants (mean [SD] age, 38.6 [12.4] years; 64% female), 27 were randomized to digital cognitive behavioral therapy for insomnia (dCBT-I) and 25 to patient education (PE). Post-intervention data were available for 50 participants (dCBT-I: n = 25; PE: n = 25). Further exploratory 3-month follow-up data were available for 25 participants in the dCBT-I group. Both groups showed significant within-group improvements in ISI scores, with no significant between-group differences. The dCBT-I group demonstrated greater improvements in sleep quality (PSQI: Cohen = 1.02, P = .012) and maladaptive sleep-related beliefs (DBAS-16: Cohen d = 1.24, P = .003). Sleep diary data indicated significant reductions in sleep onset latency (Cohen d =-0.15, P = .005) and increases in sleep efficiency (Cohen d = 0.16, P = .003) in the dCBT-I group. Adherence to dCBT-I was high (89% completed all modules), and satisfaction ratings were higher than in the PE group. While both interventions improved insomnia severity, dCBT-I provided additional benefits in sleep-related outcomes, supporting the feasibility and potential clinical utility of this culturally adapted intervention. Clinical Trial Registration: https://clinicaltrials.gov/study/NCT05822999, ClinicalTrials.gov (NCT05822999). 2026-06-01T00:00:00Z