Shared Genetic Etiology of Hwabyung (Anger Syndrome) and Somatization Symptoms in South Korean Adolescent and Young Adult Twins

AbstractSomatization is known to be more prevalent in Asian than in Western populations. Using a South Korean adolescent and young adult twin sample (N = 1754; 367 monozygotic male, 173 dizygotic male, 681 monozygotic female, 274 dizygotic female and 259 opposite-sex dizygotic twins), the present study aimed to estimate heritability of somatization and to determine common genetic and environmental influences on somatization and hwabyung (HB: anger syndrome). Twins completed self-report questionnaires of the HB symptoms scale and the somatization scale via a telephone interview. The results of the general sex-limitation model showed that 43% (95% CI [36, 50]) of the total variance of somatization was attributable to additive genetic factors, with the remaining variance, 57% (95% CI [50, 64]), being due to individual-specific environmental influences, including measurement error. These estimates were not significantly different between the two sexes. The phenotypic correlation between HB and somatization was .53 (p < .001). The bivariate model-fitting analyses revealed that the genetic correlation between the two symptoms was .68 (95% CI [.59, .77]), while the individual-specific environmental correlation, including correlated measurement error, was .41 (95% CI [.34, .48]). Of the additive genetic factors of 43% that influence somatization, approximately half (20%) were associated with those related to HB, with the remainder being due to genes unique to somatization. A substantial part (48%) of individual environmental variance in somatization was unrelated to HB; only 9% of the environmental variance was shared with HB. Our findings suggest that HB and somatization have shared genetic etiology, but environmental factors that precipitate the development of HB and somatization may be largely independent from each other.

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Sex Differences in Genetic and Environmental Contributions to Depression Symptoms in South Korean Adolescent and Young Adult Twins

Twin Research and Human Genetics ◽

10.1375/twin.11.3.306 ◽

2008 ◽

Vol 11 (3) ◽

pp. 306-313 ◽

Cited By ~ 9

Author(s):

Yoon-Mi Hur

Keyword(s):

Sex Differences ◽

Young Adult ◽

Variance Components ◽

Environmental Influences ◽

Adolescent And Young Adult ◽

Depression Symptoms ◽

East Asians ◽

South Korean ◽

Korean Adolescent ◽

Adult Twins

AbstractIt has been reported that prevalence estimates, symptom presentation, and sociocultural risk and protective factors for depression differ between Caucasian and East Asian populations. But, nonetheless, as the vast majority of twin studies of depression symptoms have been carried out using Caucasians, genetic and environmental influences on depression symptoms in East Asians remain poorly understood. In the present study, the Center for Epidemiologic Studies — Depression Scale (CES-D) was administered to 490 pairs of South Korean adolescent and young adult twins (ages: 13–23 years) by telephone interview. In males, monozygotic (MZ) and dizygotic (DZ) twin correlations were similar (.44 vs. .41), suggesting the importance of shared environmental factors in depression symptoms. In females, however, MZ twin correlation was much greater than DZ twin correlation (.40 vs. .23), indicating the importance of genetic influences. The total phenotypic variance for the CES-D was greater in females than in males. Variance components model confirmed sex differences in the magnitude of genetic and environmental influences on depression symptoms: Additive genetic, shared environmental, and individual specific environmental effects in the full model were, res pectively, 12% (95% CI: 0–54%), 32% (95% CI: 0–53%), and 56% (95% CI: 44–70%) in males, and 41% (95% CI: 0–52%), 0% (95% CI: 0–36%), and 59% (95% CI: 48–72%) in females. Similar results were observed when ‘culturally biased’ items of the CES-D were separately analyzed. These variance components estimates for depression symptoms in East Asians overlap those observed in Caucasians.

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Sex Differences in Genetic and Environmental Influences on Obsessive–Compulsive Symptoms in South Korean Adolescent and Young Adult Twins

Twin Research and Human Genetics ◽

10.1375/twin.11.3.314 ◽

2008 ◽

Vol 11 (3) ◽

pp. 314-320 ◽

Cited By ~ 11

Author(s):

Yoon-Mi Hur ◽

Hoe-Uk Jeong

Keyword(s):

Sex Differences ◽

Young Adult ◽

Statistical Power ◽

Statistical Significance ◽

Environmental Influences ◽

Adolescent And Young Adult ◽

Obsessive Compulsive ◽

Obsessive Compulsive Symptoms ◽

Compulsive Disorder ◽

South Korean

AbstractRecent molecular genetic studies provide suggestive evidence for sexual dimorphism in genetics of obsessive-compulsive disorder. However, only a few twin studies have addressed the question of sex differences in genetic and environmental contributions to variation of obsessive–compulsive symptoms. The aim of the present study was to estimate genetic and environmental influences on obsessive–compulsive symptoms in South Korean twins, with a special emphasis on sex difference. In total, 751 adolescent and young adult twin pairs (ages: 13–23 years) completed a Korean version of the 30 items of the Maudsley Obsessional — Compulsive Inventory (MOCI) through a mail survey. A sum of the answers for the 30 items was calculated to represent a total score for obsessive–compulsive symptoms (hereafter, the MOCIT). Males had significantly higher variance of the MOCIT than did females. In males, monozygotic (MZ) twin correlation was significantly higher than dizygotic (DZ) twin correlations (.56 vs. .24), whereas in females, MZ and DZ twin correlations were not significantly different from each other (.39 vs. .36). The general sex-limitation model was applied to the twin data. The results of model-fitting analyses indicated that the unstandardized genetic variance as well as heritability estimate (53% vs. 41%) for the MOCIT was higher in males than in females. However, shared environmental influences did not attain statistical significance perhaps due to insufficient statistical power.

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Genetic and Environmental Covariations Among Obsessive–Compulsive Symptoms, Neuroticism, and Extraversion in South Korean Adolescent and Young Adult Twins

Twin Research and Human Genetics ◽

10.1375/twin.12.2.142 ◽

2009 ◽

Vol 12 (2) ◽

pp. 142-148 ◽

Cited By ~ 10

Author(s):

Yoon-Mi Hur

Keyword(s):

Young Adult ◽

Genetic Factors ◽

Genetic Correlations ◽

Mental Illnesses ◽

Adolescent And Young Adult ◽

Obsessive Compulsive ◽

Compulsive Disorder ◽

South Korean ◽

Psychiatric Illnesses ◽

Adult Twins

AbstractA growing literature suggests that personality traits may be endophenotype markers for psychiatric illnesses. Although the phenotypic relationships between obsessive–compulsive disorder (OCD) and high neuroticism and low extraversion have been well documented, underlying genetic and environmental contributions to these associations have not been explored previously. Five hundred and twenty-four monozygoitc (MZ) and 228 dizygotic (DZ) pairs of adolescent and young adult twins (aged 13–24 years) drawn from the South Korean Twin Registry completed the Maudsley Obsessive Compulsive Inventory (MOCI) and the Neuroticism and Extraversion scale of the Eysenck Personality Scale by mail. The total score of MOCI (MOCIT) was significantly and positively correlated with Neuroticism (r= .44), but only weakly and negatively related to Extraversion (r= –.10). A trivariate Cholesky model was applied to the data. The additive genetic correlations in the best-fitting model were .51 between Neuroticism and MOCIT and –.17 between Extraversion and MOCIT, suggesting that additive genetic factors that lead to high neuroticism and low extraversion overlap with those genetic factors influencing high OC symptoms. These findings add to the cumulative evidence of the shared genetic etiology for the associations between a personality profile of high neuroticism and low extraversion and mental illnesses.

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Heritability of Hwabyung Symptoms in South Korean Adolescent and Young Adult Twins

Twin Research and Human Genetics ◽

10.1017/thg.2018.40 ◽

2018 ◽

Vol 21 (5) ◽

pp. 378-383 ◽

Cited By ~ 3

Author(s):

Yoon-Mi Hur ◽

Eun-ji Choi ◽

Jong-Woo Kim ◽

Hee-Jeong Jin ◽

Siwoo Lee

Keyword(s):

Young Adult ◽

Environmental Influences ◽

Model Fitting ◽

Adolescent And Young Adult ◽

Parameter Estimates ◽

Present Sample ◽

South Korean ◽

Opposite Sex ◽

Estimate Heritability ◽

Adult Twins

The present study aimed to estimate heritability of Hwabyung (HB) symptoms in adolescent and young adult twins in South Korea. The sample included 1,601 twins consisting of 143 pairs of monozygotic male (MZM), 67 pairs of dizygotic male (DZM), 295 pairs of monozygotic female (MZF), 114 pairs of dizygotic female (DZF), and 117 pairs of opposite-sex dizygotic (OSDZ) twins and 129 twins with non-participating co-twins (mean age = 19.1 ± 3.1 years; range: 12–29 years). An HB symptom questionnaire was given to twins via a telephone interview. Consistent with the literature of HB, the mean level of HB was significantly higher in females than in males. Maximum likelihood twin correlations for HB were 0.31 (95% CI [0.16, 0.45]) for MZM, 0.19 (95% CI [-0.05, 0.41]) for DZM, 0.50 (95% CI [0.41, 0.58]) for MZF, 0.28 (95% CI [0.11, 0.44]) for DZF, and 0.23 (95% CI [0.05, 0.40]) for OSDZ twins. These patterns of twin correlations suggested the presence of additive genetic influences on HB. Model-fitting analysis showed that additive genetic and individual-specific environmental influences on HB were 44% (95% CI [37, 51]) and 56% (95% CI [49, 63]), respectively. Shared environmental influences were not significant. These parameter estimates were not significantly different between two sexes, and did not change significantly with age in the present sample, suggesting that genetic and environmental influences on HB in both sexes are stable across adolescence and young adulthood.

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Nonadditive Genetic Effects on Hostility in South Korean Adolescent and Young Adult Twins

Twin Research and Human Genetics ◽

10.1375/twin.9.5.637 ◽

2006 ◽

Vol 9 (5) ◽

pp. 637-641 ◽

Cited By ~ 11

Author(s):

Yoon-Mi Hur

Keyword(s):

Young Adult ◽

Twin Studies ◽

Adolescent And Young Adult ◽

Human Populations ◽

South Korean ◽

Best Fitting ◽

Opposite Sex ◽

Korean Adolescent ◽

Adult Twins ◽

Hostility Scale

AbstractHostility has been shown to be a vulnerability marker for various health problems. The present study examined genetic and environmental contributions to individual differences in hostility in South Korean adolescent and young adult twins. Seven hundred and nineteen same- and opposite-sex twin pairs aged from 13 to 23 years completed a hostility scale. The scalar sex-limitation model was applied to the data. The best fitting model indicated that 34% of the total variation of hostility was attributable to genetic factors operating in a nonadditive manner. The remaining 66% of the variance was associated with nonshared environmental influences and measurement error. These findings were largely consistent with results from previous twin studies of personality based on Caucasian twins, rendering support for the pervasive influence of genetic non-additivity on human personality traits and the generalization of the heritability of personality across human populations.

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Twin Study of the Relationship between Childhood Negative Emotionality and Hyperactivity/Inattention Problems

Twin Research and Human Genetics ◽

10.1017/thg.2021.5 ◽

2021 ◽

Vol 24 (1) ◽

pp. 7-13

Author(s):

Yoon-Mi Hur ◽

Hoe-Uk Jeong

Keyword(s):

Genetic Factors ◽

Environmental Influences ◽

Model Fitting ◽

Negative Emotionality ◽

Phenotypic Correlation ◽

Environmental Correlation ◽

South Korean ◽

Telephone Interviews ◽

Opposite Sex ◽

The Relationship

AbstractThe present study aimed to determine the genetic and environmental etiology of the association between childhood negative emotionality (NE) and hyperactivity/inattention problems (HIP) using South Korean elementary school twins (mean age = 10.19 years, SD = 1.79 years). Telephone interviews were given to mothers of 919 twins (229 monozygotic males: 112 pairs and 5 individuals; 148 dizygotic males: 73 pairs and 2 individuals; 180 monozygotic females: 87 pairs and 6 individuals; 103 dizygotic females: 50 pairs and 3 individuals; 259 opposite-sex dizygotic twins: 127 pairs and 5 individuals) to assess their children’s NE and HIP. Consistent with prior studies, the phenotypic correlation between NE and the HIP was moderate (r = .29; 95% CI = .24, .34). Model-fitting analysis revealed that additive genetic and nonshared environmental influences on NE were .45 (95% CI [.34, .54]) and .55 (95% CI [.46, .66]), respectively, and that additive and nonadditive genetic, and nonshared environmental influences on HIP were .08 (95% CI [.03, .26]), .41 (95% CI [.21, .51]) and .51 (95% CI = .42, .61), respectively. In addition, the additive genetic correlation between NE and HIP was 1.0 (95% CI [.52, 1.00]), indicating that additive genetic factors are entirely shared between the two phenotypes. Nonadditive genetic influences were unique to HIP and not responsible for the NE-HIP association. Nonshared environmental correlation was significant but modest (re = .18, 95% CI [.06, .30]).

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Factors That Explain Adolescent and Young Adult Mobile Game Play, Part 1

Advances in Game-Based Learning - Handbook of Research on Serious Games for Educational Applications ◽

10.4018/978-1-5225-0513-6.ch015 ◽

2017 ◽

pp. 320-339 ◽

Cited By ~ 3

Author(s):

Boaventura DaCosta ◽

Soonhwa Seok

Keyword(s):

Young Adult ◽

Mobile Phones ◽

Video Game ◽

Well Being ◽

Adolescent And Young Adult ◽

Game Play ◽

Mobile Game ◽

South Korean ◽

Game Features ◽

Video Game Player

The first of two chapters, a study is presented that quantitatively examined the adolescent and young adult “casual” video game player. A total of 1,950 South Korean students self-reported their game play on mobile phones by answering a 92-item questionnaire designed to capture data on technology ownership; preference for game genre and titles; where and how often games were played; what factors influence game selection, what game features were the most desirable, the rationale behind playing games, and psychophysical changes experienced as a result of playing; as well as, spending habits with regard to game purchases. The findings supported many of the claims made about the casual player, revealing, for example, that mobile games are predominately played for short periods of time, in between activities, and as a means to combat boredom. Adding credence to the idea that mobile game play can be viewed as a casual activity. Results also revealed potentially positive benefits, to include improved mood and feelings of well-being along with better mental attention and focus.

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Feeling of Cold Hands and Feet is a Highly Heritable Phenotype

Twin Research and Human Genetics ◽

10.1375/twin.15.2.166 ◽

2012 ◽

Vol 15 (2) ◽

pp. 166-169 ◽

Cited By ~ 21

Author(s):

Yoon-Mi Hur ◽

Jeong-Ho Chae ◽

Ki Wha Chung ◽

Jung Jin Kim ◽

Hoe-Uk Jeong ◽

...

Keyword(s):

Sex Differences ◽

Measurement Error ◽

General Population ◽

Environmental Influences ◽

Model Fitting ◽

Environmental Variance ◽

Best Fitting ◽

Heritable Phenotype ◽

Hands And Feet ◽

Fitting Model

The prevalence of the feeling of cold hands and feet (FCHF) is high in the general population but the etiology of FCHF is largely unknown. The aim of the present study was to explore whether the FCHF is heritable. Eight hundred and ninety-four pairs of twins completed a question about FCHF. Tetrachoric correlations for FCHF were .58, .29, .67, .52, and .04 for monozygotic male, dizygotic male, monozygotic female, and dizygotic female twins, respectively. Model-fitting analyses suggested that in the best fitting model, additive genetic and nonshared environmental variance including measurement error were 64% (95% CI: 55%-72%) and 36% (28%-45%), respectively. Sex differences in genetic and environmental influences were not significant.

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