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Trastornos por Estrés Postraumático , Humanos , Femenino , Trastornos por Estrés Postraumático/genética , Trastornos por Estrés Postraumático/psicología , Masculino , Enfermedades en Gemelos/genética , Enfermedades en Gemelos/psicología , Factores Sexuales , Adulto , Caracteres Sexuales , Gemelos Monocigóticos/genética , Gemelos Monocigóticos/psicologíaRESUMEN
OBJECTIVE: Twin studies have demonstrated that posttraumatic stress disorder (PTSD) is moderately heritable, and the pattern of findings across studies suggests higher heritability in females compared with males. Formal testing of sex differences has yet to be done in twin studies of PTSD. The authors sought to estimate the genetic and environmental contributions to PTSD, and to formally test for sex differences, in the largest sample to date of both sexes, among twins and siblings. METHODS: Using the Swedish National Registries, the authors performed structural equation modeling to decompose genetic and environmental variance for PTSD and to formally test for quantitative and qualitative sex differences in twins (16,242 pairs) and in full siblings within 2 years of age of each other (376,093 pairs), using diagnostic codes from medical registries. RESULTS: The best-fit model suggested that additive genetic and unique environmental effects contributed to PTSD. Evidence for a quantitative sex effect was found, such that heritability was significantly greater in females (35.4%) than males (28.6%). Evidence of a qualitative sex effect was found, such that the genetic correlation was high but less than complete (rg=0.81, 95% CI=0.73-0.89). No evidence of shared environment or special twin environment was found. CONCLUSIONS: This is the first demonstration of quantitative and qualitative sex effects for PTSD. The results suggest that unique environmental effects, but not the shared environment, contributed to PTSD and that genetic influences for the disorder are stronger in females compared with males. Although the heritability is highly correlated, it is not at unity between the sexes.
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Sistema de Registros , Hermanos , Trastornos por Estrés Postraumático , Humanos , Trastornos por Estrés Postraumático/genética , Trastornos por Estrés Postraumático/diagnóstico , Trastornos por Estrés Postraumático/psicología , Trastornos por Estrés Postraumático/epidemiología , Masculino , Femenino , Suecia/epidemiología , Hermanos/psicología , Factores Sexuales , Adulto , Enfermedades en Gemelos/genética , Enfermedades en Gemelos/psicología , Persona de Mediana Edad , Gemelos/genética , Gemelos/psicología , Gemelos Monocigóticos/genética , Gemelos Monocigóticos/psicología , Interacción Gen-AmbienteRESUMEN
The commentary delves into the implications of "assortative parenting" and "assortative cross-parenting," as introduced by N. L. Segal, and situates these concepts within the framework of current research. It addresses the joys and complexities of raising twins, highlighting how their concurrent development stages can amplify parental favoritism and heighten the challenge of addressing each twin's unique needs. This interplay provides a rich context to investigate assortative parenting practices. Additionally, this paper contemplates the broader picture of twin studies, particularly how the care of monozygotic twins (who share 100 % of their genes) and dizygotic twins (who share 50 % of their genes, on average) may reveal the intertwined nature of genetics and environment in parenting strategies. It also proposes that twins' interactions with other family members, their spouses, and peers can offer profound insights into the phenomena of phenotypic assortative affiliation, enriching our understanding of close relational bonds.
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Relaciones Padres-Hijo , Responsabilidad Parental , Niño , Humanos , Responsabilidad Parental/psicología , Padres/psicología , Gemelos Monocigóticos/psicología , Gemelos Monocigóticos/genéticaRESUMEN
Importance: Exposure to adverse childhood experiences (ACEs) has consistently been associated with multiple negative mental health outcomes extending into adulthood. However, given that ACEs and psychiatric disorders cluster within families, it remains to be comprehensively assessed to what extent familial confounding contributes to associations between ACEs and clinically confirmed adult psychiatric disorders. Objective: To investigate whether associations between ACEs and adult mental health outcomes remain after adjusting for familial (genetic and environmental) confounding. Design, Setting, and Participants: This Swedish twin cohort study used a discordant twin pair design based on monozygotic (MZ) and dizygotic (DZ) twins. A total of 25â¯252 adult twins (aged 18-47 years) from the Swedish Twin Registry born between 1959 and 1998 were followed up from age 19 years until 2016, with a maximum follow-up time of 39 years. Data were analyzed from April 2022 to November 2023. Exposures: A total of 7 ACEs, including family violence, emotional abuse or neglect, physical neglect, physical abuse, sexual abuse, rape, and hate crime, were assessed with items from the Life Stressor Checklist-Revised in a web-based survey. Main Outcomes and Measures: Adult (ages >18 years) clinical diagnosis of psychiatric disorders (ie, depressive, anxiety, alcohol or drug misuse, or stress-related disorders) were obtained from the Swedish National Patient Register. Results: Of 25â¯252 twins included in the study (15â¯038 female [59.6%]; mean [SD] age at ACE assessment, 29.9 [8.7] years), 9751 individuals (38.6%) reported exposure to at least 1 ACE. A greater number of ACEs was associated with increased odds of any psychiatric disorder in the full cohort (odds ratio [OR] per additional ACE, 1.52; 95% CI, 1.48-1.57). The association remained but ORs per additional ACE were attenuated in DZ (1.29; 95% CI, 1.14-1.47) and MZ (1.20; 95% CI, 1.02-1.40) twin pairs. Individuals who were exposed to sexual abuse compared with those who were not exposed had increased odds of any clinically confirmed psychiatric disorder in all comparisons: full cohort (OR, 3.09; 95% CI, 2.68-3.56), DZ twin pairs (OR, 2.10; 95% CI, 1.33-3.32), and MZ twin pairs (1.80; 95% CI, 1.04-3.11). Conclusions and relevance: This study found that associations between ACEs and adult mental health outcomes remained after controlling for shared genetic and environmental factors, which was particularly evident after multiple ACEs or sexual abuse. These findings suggest that targeted interventions may be associated with reduced risks of future psychopathology.
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Experiencias Adversas de la Infancia , Trastornos Mentales , Humanos , Adulto , Femenino , Masculino , Experiencias Adversas de la Infancia/estadística & datos numéricos , Suecia/epidemiología , Persona de Mediana Edad , Adulto Joven , Adolescente , Trastornos Mentales/epidemiología , Trastornos Mentales/psicología , Sistema de Registros/estadística & datos numéricos , Estudios de Cohortes , Gemelos Monocigóticos/psicología , Gemelos Dicigóticos/psicología , Gemelos Dicigóticos/estadística & datos numéricos , Salud Mental/estadística & datos numéricosRESUMEN
Considerable evidence supports the role of present-moment attention, a central feature of mindfulness, in subjective wellbeing maintenance and enhancement. Yet it is not clear why such a relation exists. This study examined the genetic and environmental contributions of present-moment attention to subjective wellbeing. Consistent with the "generalist genes hypothesis" and prior evidence, we hypothesized that presence and subjective wellbeing would show a substantial genetic correlation and smaller environmental correlation. Using a large epidemiological sample of healthy 16-year-old twins in the United Kingdom (N = 1136 monozygotic (MZ) and dizygotic (DZ) twin pairs), genetic overlap was found between presence and the cognitive component of subjective wellbeing (life satisfaction), and to a lesser extent, the affective component of subjective wellbeing (operationalized as happiness). The non-shared environmental overlap between these constructs was substantial. This study provides the first evidence known to us showing that present-centered attention, a primary component of mindfulness, has both genetic and environmental overlap with subjective wellbeing. The findings have implications for understanding mechanisms by which presence is associated with positive emotions and life satisfaction, and suggest, pending additional research, that mindfulness-based interventions to enhance wellbeing may be best suited to those with a genetic propensity toward mindful presence.
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Atención Plena , Gemelos Dicigóticos , Humanos , Adolescente , Gemelos Dicigóticos/genética , Gemelos Dicigóticos/psicología , Felicidad , Reino Unido , Gemelos Monocigóticos/genética , Gemelos Monocigóticos/psicologíaRESUMEN
BACKGROUND: The causes of obsessive-compulsive disorder (OCD) remain unknown. Gene-searching efforts are well underway, but the identification of environmental risk factors is at least as important and should be a priority because some of them may be amenable to prevention or early intervention strategies. Genetically informative studies, particularly those employing the discordant monozygotic (MZ) twin design, are ideally suited to study environmental risk factors. This protocol paper describes the study rationale, aims, and methods of OCDTWIN, an open cohort of MZ twin pairs who are discordant for the diagnosis of OCD. METHODS: OCDTWIN has two broad aims. In Aim 1, we are recruiting MZ twin pairs from across Sweden, conducting thorough clinical assessments, and building a biobank of biological specimens, including blood, saliva, urine, stool, hair, nails, and multimodal brain imaging. A wealth of early life exposures (e.g., perinatal variables, health-related information, psychosocial stressors) are available through linkage with the nationwide registers and the Swedish Twin Registry. Blood spots stored in the Swedish phenylketonuria (PKU) biobank will be available to extract DNA, proteins, and metabolites, providing an invaluable source of biomaterial taken at birth. In Aim 2, we will perform within-pair comparisons of discordant MZ twins, which will allow us to isolate unique environmental risk factors that are in the causal pathway to OCD, while strictly controlling for genetic and early shared environmental influences. To date (May 2023), 43 pairs of twins (21 discordant for OCD) have been recruited. DISCUSSION: OCDTWIN hopes to generate unique insights into environmental risk factors that are in the causal pathway to OCD, some of which have the potential of being actionable targets.
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Trastorno Obsesivo Compulsivo , Gemelos Monocigóticos , Femenino , Humanos , Recién Nacido , Embarazo , Encéfalo , Enfermedades en Gemelos , Trastorno Obsesivo Compulsivo/etiología , Trastorno Obsesivo Compulsivo/genética , Factores de Riesgo , Gemelos Monocigóticos/genética , Gemelos Monocigóticos/psicología , Estudios en Gemelos como AsuntoRESUMEN
BACKGROUND: Are genetic risk factors for current depressive symptoms good proxies for genetic risk factors for syndromal major depression (MD)? METHODS: In over 9000 twins from the population-based Virginia Adult Twin Study of Psychiatric and Substance Use Disorders, the occurrence of all nine DSM symptomatic criteria for MD in the last year was assessed at personal interview and then grouped by their temporal co-occurrence. The DSM criteria which occurred outside (OUT) v. inside of (IN) MD episodes were then separated. We calculated tetrachoric correlations for OUT and IN depressive criteria in monozygotic (MZ) and dizygotic (DZ) pairs and fitted univariate and bivariate ACE twin models using OpenMx. RESULTS: The mean twin correlations (±95% CIs) for IN depressive criteria were substantially higher than for OUT depressive criteria in both MZ [+0.35 (0.32-0.38) v. 0.20 (0.17-0.24)] and DZ pairs [0.20 (0.17-0.24) v. 0.10 (0.04-0.16]. The mean IN-OUT cross-correlation in MZ and DZ pairs was modest [+0.15 (0.07-0.24) and +0.07 (0.03-0.12)]. The mean heritability estimates for the nine In v. Out depressive criteria was 0.31 (0.22-0.41) and 0.15 (0.08-0.21), in MZ and DZ pairs, respectively. The mean genetic correlation between the nine IN and OUT depressive criteria was +0.07 (-0.07 to 0.21). CONCLUSIONS: Depressive criteria occurring outside depressive episodes are less heritable than those occurring within. These two ways criteria can manifest are not closely genetically related. Current depressive symptoms - most of which are occurring outside of depressive episodes - are not, for genetic studies, good proxies for MD.
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Trastorno Depresivo Mayor , Adulto , Humanos , Trastorno Depresivo Mayor/diagnóstico , Trastorno Depresivo Mayor/epidemiología , Trastorno Depresivo Mayor/genética , Depresión/genética , Gemelos Monocigóticos/genética , Gemelos Monocigóticos/psicología , Gemelos Dicigóticos/genética , Gemelos Dicigóticos/psicología , Enfermedades en Gemelos/diagnóstico , Enfermedades en Gemelos/genética , Enfermedades en Gemelos/epidemiologíaRESUMEN
Importance: Subjective memory concern has long been considered a state-related indicator of impending cognitive decline or dementia. The possibility that subjective memory concern may itself be a heritable trait is largely ignored, yet such an association would substantially confound its use in clinical or research settings. Objective: To assess the heritability and traitlike dimensions of subjective memory concern and its clinical correlates. Design, Setting, and Participants: This longitudinal twin cohort study was conducted from 1967 to 2019 among male adults with a mean (SD) age of 37.75 (2.52) years to follow-up at mean ages of 56.15 (2.72), 61.50 (2.43), and 67.35 (2.57) years (hereafter, 38, 56, 62, and 67 years, respectively) in the Vietnam Era Twin Study of Aging. The study included a national community-dwelling sample with health, education, and lifestyle characteristics comparable to a general sample of US men in this age cohort. Participants were monozygotic and dizygotic twins randomly recruited from the Vietnam Era Twin Registry. Data were analyzed from May 2021 to December 2022. Main Outcomes and Measures: Measures included subjective memory concern at 4 time points; objective memory, depressive symptoms, and anxiety at the last 3 time points; negative emotionality (trait neuroticism) at age 56 years; polygenic risk scores (PRSs) for neuroticism, depression, and Alzheimer disease; APOE genotype; and parental history of dementia. Primary outcomes were heritability and correlations between subjective memory concern and other measures. Results: The sample included 1555 male adults examined at age 38 years, 520 at age 56 years (due to late introduction of subjective memory concern questions), 1199 at age 62 years, and 1192 at age 67 years. Phenotypically, subjective memory concerns were relatively stable over time. At age 56 years, subjective memory concern had larger correlations with depressive symptoms (r, 0.32; 95% CI, 0.21 to 0.42), anxiety (r, 0.36; 95% CI, 0.18 to 0.51), and neuroticism (r, 0.34; 95% CI, 0.26 to 0.41) than with objective memory (r, -0.24; 95% CI, -0.33 to -0.13). Phenotypic results were similar at ages 62 and 67 years. A best-fitting autoregressive twin model indicated that genetic influences on subjective memory concern accumulated and persisted over time (h2 = 0.26-0.34 from age 38-67 years). At age 56 years, genetic influences for subjective memory concern were moderately correlated with genetic influences for anxiety (r, 0.36; 95% CI, 0.18 to 0.51), negative emotionality (r, 0.51; 95% CI, 0.44-0.57), and depressive symptoms (r, 0.20; 95% CI, 0.10 to 0.29) as well as objective memory (r, -0.22; 95% CI, -0.30 to -0.14). Similar genetic correlations were seen at ages 62 and 67 years. The neuroticism PRS was associated with subjective memory concern at age 38 years (r, 0.10; 95% CI, 0.03. to 0.18) and age 67 years (r, 0.09; 95% CI, 0.01 to 0.16). Subjective memory concern was not associated with any Alzheimer disease risk measures. Conclusions and Relevance: This cohort study found stable genetic influences underlying subjective memory concern dating back to age 38 years. Subjective memory concern had larger correlations with affect-related measures than with memory-related measures. Improving the utility of subjective memory concern as an indicator of impending cognitive decline and dementia may depend on isolating its statelike component from its traitlike component.
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Enfermedad de Alzheimer , Humanos , Masculino , Adulto , Persona de Mediana Edad , Anciano , Estudios de Cohortes , Gemelos Dicigóticos/psicología , Estudios Longitudinales , Factores de Riesgo , Gemelos Monocigóticos/psicologíaRESUMEN
Importance: General and specific factors of psychopathology are associated with future adverse outcomes, indicating that they might be useful for identifying individuals at greatest risk. However, it remains unknown if these associations are attributable to confounders that may influence both the psychopathology factors and later outcomes. Objective: To analyze associations between psychopathology factors and clinically relevant outcomes within family pairs, adjusting for unmeasured confounds by applying co-twin control and sibling comparison designs. Design, Setting, and Participants: This longitudinal cohort study with a follow-up range of 9 to 13 years included all Swedish twins born from 1959 to 1985 who participated in the Study of Twin Adults: Genes and Environment (60% response rate) and the oldest pair of all Swedish siblings born from 1959 to 1985 per the Multi-Generation Register. Twins were evaluated based on responses to a hierarchical factor model derived using multivariate statistics. Sibling pairs were evaluated based on psychiatric diagnoses per the Swedish National Patient Register. Information on outcome events and prescriptions were derived from the National Patient Register, Prescribed Drug Register, and Crime Register. Baseline assessment was in August 2005, and data were analyzed from January 2022 to February 2023. Exposures: Hierarchical factor model consisting of 1 general and 4 specific factors fit to 48 psychiatric symptoms on which twin participants self-reported in 2005 and 1 general and 3 specific factors fit to 9 register-based psychiatric diagnoses assigned to sibling participants prior to 2005. Main Outcomes and Measures: Outcomes consisted of 7 register-based events occurring after 2005, including suicidal behavior, substance overdoses, and criminal suspicion or convictions (data available until the end of 2013), and prescription of antidepressants, antialcohol or antiopioid medication, antipsychotics, and stimulants (data available until the end of 2017). Results: The study included 32â¯328 twins (mean [SD] age, 34 [8] years; 16â¯076 [49.73%] male) and 1â¯942â¯106 siblings (mean [SD] age, 34 [7] years; 991â¯500 [51.05%] male). General psychopathology was significantly associated with all 7 outcomes within sibling pairs (mean within-pair odds ratio [OR], 2.28; 95% CI, 2.19-2.37) and dizygotic twin pairs (within-pairs OR, 1.65; 95% CI, 1.38-1.98) and with 3 outcomes within monozygotic twin pairs (mean within-pairs OR, 1.77; 95% CI, 1.35-2.36). Within sibling pairs, the specific internalizing factor was associated with antidepressant prescriptions (within-pairs OR, 1.65; 95% CI, 1.59-1.71), the specific substance misuse factor was associated prescription of antialcohol and antiopioid medication (within-pairs OR, 2.36; 95% CI, 2.20-2.54), and the specific psychotic factor was associated with antipsychotic medications (within-pairs OR, 1.61; 95% CI, 1.51-1.72). Similar results emerged within twin pairs. Conclusion and Relevance: In this cohort study, general psychopathology was significantly associated with all 7 outcomes within sibling and dizygotic twin pairs and 3 outcomes within monozygotic twin pairs at 10 years. Within twin and sibling pairs, the specific factors were primarily associated with related outcomes. Several of the associations in this cohort study could not be attributed to unmeasured confounds shared by family members, suggesting that interventions toward broad psychopathology dimensions might help reduce the risk of future clinically relevant events.
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Trastornos Mentales , Hermanos , Humanos , Adulto , Masculino , Femenino , Estudios Longitudinales , Suecia/epidemiología , Gemelos Monocigóticos/psicología , Trastornos Mentales/epidemiología , Trastornos Mentales/genética , Gemelos Dicigóticos/psicología , Sistema de RegistrosRESUMEN
The experience of going through the personal library of our late esteemed twin research colleague, Dr Irving I. Gottesman, is described. I came away with fond memories and unexpected treasures. This essay is followed by brief reviews of timely research on factors affecting callous-unemotional traits, depressive symptoms in prospective Chinese twin mothers, twins with sagittal suture craniosynostosis, and creative expressiveness and educational achievement. Media reports on informative topics of interest to researchers and the general public include male-female twin Holocaust survivors, nontuplets born in Mali, Indian twins who married the same man, twins born from the longest frozen embryos, an infant twin abduction and twins born in different years.
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Estudios en Gemelos como Asunto , Humanos , Trastorno de la Conducta , Craneosinostosis/genética , Depresión/genética , Pueblos del Este de Asia , Escolaridad , Holocausto , Malí , Madres , Estudios Prospectivos , Sobrevivientes , Suturas , Gemelos Monocigóticos/psicología , Creatividad , Estudios en Gemelos como Asunto/historia , Historia del Siglo XXRESUMEN
PURPOSE: Parenting style has been associated with children's weight-related outcomes and health behaviors, but this relationship may be confounded by genetic influences. Using a twin design to better control for genetics and shared home environments, this study aimed to estimate the longitudinal parental effects on obesity, smoking, and drinking in children and adolescents. METHODS: Data were retrieved from the first two waves of the German Twin Family Panel. A total of 631 pairs of same-sex monozygotic twins were analyzed, including three birth cohorts aged 5, 11, and 17 years. Self-reported parenting styles were measured in five dimensions: emotional warmth, psychological control, negative communication, monitoring, and inconsistent parenting. Outcome variables included children's body mass index z-score (BMIz) and smoking and alcohol drinking frequency. The differencing method was used to examine the relationship between within-monozygotic pair differences in parenting styles and health outcomes, controlling for differences at baseline, genetic influences, and other shared characteristics between twins. RESULTS: Controlling for genetics, shared environmental effects, and body weight status at baseline, the twin who received harsher parenting in communication had lower BMI than their cotwin. Subgroup analyses found that negative communication had a stronger impact on the youngest cohort and female twins. Paternal parenting differentially relates to child weight compared to maternal parenting. No concurrent and long-lasting effects of paternal parenting on smoking and drinking were found. DISCUSSION: The twin study design is a unique epidemiological tool to measure the contribution of genetics as opposed to the environment, to a given health trait. This study found that negative communication was associated with lower BMI in German twin families. However, it failed to identify strong evidence for the causal link between other parenting dimensions and child's weight status and alcohol and tobacco use. More twin studies with objective measurements are warranted to understand the critical role of parenting, especially family communication, in predicting children's BMIs and their health behaviors across cultures.
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Responsabilidad Parental , Padres , Adolescente , Niño , Femenino , Humanos , Masculino , Obesidad , Responsabilidad Parental/psicología , Fumar/epidemiología , Gemelos Monocigóticos/genética , Gemelos Monocigóticos/psicologíaRESUMEN
The purpose of this study was to assess the speaker-discriminatory potential of a set of speech timing parameters while probing their suitability for forensic speaker comparison applications. The recordings comprised of spontaneous dialogues between twin pairs through mobile phones while being directly recorded with professional headset microphones. Speaker comparisons were performed with twins speakers engaged in a dialogue (i.e., intra-twin pairs) and among all subjects (i.e., cross-twin pairs). The participants were 20 Brazilian Portuguese speakers, ten male identical twin pairs from the same dialectal area. A set of 11 speech timing parameters was extracted and analyzed, including speech rate, articulation rate, syllable duration (V-V unit), vowel duration, and pause duration. Three system performance estimates were considered for assessing the suitability of the parameters for speaker comparison purposes, namely global Cllr, EER, and AUC values. These were interpreted while also taking into consideration the analysis of effect sizes. Overall, speech rate and articulation rate were found the most reliable parameters, displaying the largest effect sizes for the factor "speaker" and the best system performance outcomes, namely lowest Cllr, EER, and highest AUC values. Conversely, smaller effect sizes were found for the other parameters, which is compatible with a lower explanatory potential of the speaker identity on the duration of such units and a possibly higher linguistic control regarding their temporal variation. In addition, there was a tendency for speech timing estimates based on larger temporal intervals to present larger effect sizes and better speaker-discriminatory performance. Finally, identical twin pairs were found remarkably similar in their speech temporal patterns at the macro and micro levels while engaging in a dialogue, resulting in poor system discriminatory performance. Possible underlying factors for such a striking convergence in identical twins' speech timing patterns are presented and discussed.
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Habla , Gemelos Monocigóticos/psicología , Adulto , Psicología Forense , Humanos , Masculino , Fonética , Percepción del Habla , Grabación en Cinta , Factores de Tiempo , Adulto JovenRESUMEN
BACKGROUND: Many cognitive functions are under strong genetic control and twin studies have demonstrated genetic overlap between some aspects of cognition and schizophrenia. How the genetic relationship between specific cognitive functions and schizophrenia is influenced by IQ is currently unknown. METHODS: We applied selected tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) to examine the heritability of specific cognitive functions and associations with schizophrenia liability. Verbal and performance IQ were estimated using The Wechsler Adult Intelligence Scale-III and the Danish Adult Reading Test. In total, 214 twins including monozygotic (MZ = 32) and dizygotic (DZ = 22) pairs concordant or discordant for a schizophrenia spectrum disorder, and healthy control pairs (MZ = 29, DZ = 20) were recruited through the Danish national registers. Additionally, eight twins from affected pairs participated without their sibling. RESULTS: Significant heritability was observed for planning/spatial span (h2 = 25%), self-ordered spatial working memory (h2 = 64%), sustained attention (h2 = 56%), and movement time (h2 = 47%), whereas only unique environmental factors contributed to set-shifting, reflection impulsivity, and thinking time. Schizophrenia liability was associated with planning/spatial span (rph = -0.34), self-ordered spatial working memory (rph = -0.24), sustained attention (rph = -0.23), and set-shifting (rph = -0.21). The association with planning/spatial span was not driven by either performance or verbal IQ. The remaining associations were shared with performance, but not verbal IQ. CONCLUSIONS: This study provides further evidence that some cognitive functions are heritable and associated with schizophrenia, suggesting a partially shared genetic etiology. These functions may constitute endophenotypes for the disorder and provide a basis to explore genes common to cognition and schizophrenia.
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Esquizofrenia , Adulto , Humanos , Esquizofrenia/genética , Gemelos Monocigóticos/psicología , Gemelos Dicigóticos/genética , Cognición , Pruebas NeuropsicológicasRESUMEN
BACKGROUND: Physical distancing and other COVID-19 pandemic mitigation strategies have negatively impacted physical activity (PA) levels and mental health in cross-sectional studies. The purpose of this study was to investigate associations between changes in PA and mental health outcomes during the COVID-19 pandemic, following implementation of mitigation strategies, in a sample of adult twins. METHODS: This was a prospective study of 3,057 adult twins from the Washington State Twin Registry. Study participants completed online surveys in 2020, at baseline (March 26 -April 5), and three follow-up waves (W1: April 20 -May 3; W2: Jul 16 -Aug 2; W3: Sept 16 -Oct 1). Physical activity was operationalized as self-reported moderate-to-vigorous PA (MVPA) and neighborhood walking (minutes/week), and mental health outcomes, operationalized as self-reported anxiety and perceived stress were assessed in the three waves of follow-up. Latent growth curve models (LGCMs) were used to assess changes in PA and mental health outcomes over time. Parallel LGCMs were used to estimate the cross-sectional, parallel, and prospective associations between PA and mental health over time. All models took into within-pair correlations and adjusted for age, sex, and race. RESULTS: Individuals' amount of MVPA and walking decreased over time, whereas levels of anxiety remained stable, and stress increased slightly. Cross-sectional associations observed between both PA predictors and mental health outcomes were weak. After taking into account cross-sectional associations between PA and mental health outcomes, changes in PA over time were not associated with changes in mental health outcomes over time. CONCLUSIONS: Over a time period aligned with COVID-19 mitigation strategies and social restrictions, changes in physical activity was not associated with changes in anxiety or stress levels in the current sample. Nonetheless, the average decline in PA over time is worrisome. Public health resources should continue to promote PA as a means to improve physical health during the pandemic.
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COVID-19/psicología , Ejercicio Físico , Salud Mental , Estrés Psicológico/epidemiología , Gemelos Monocigóticos/psicología , Adulto , Anciano , COVID-19/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estrés Psicológico/genética , Gemelos Monocigóticos/estadística & datos numéricosRESUMEN
In recent years, evidence has accumulated with regard to the ubiquity of pleiotropy across the genome, and shared genetic etiology is thought to play a large role in the widespread comorbidity among psychiatric disorders and risk factors. Recent methods investigate pleiotropy by estimating genetic correlation from genome-wide association summary statistics. More comprehensive estimates can be derived from the known relatedness between genetic relatives. Analysis of extended twin pedigree data allows for the estimation of genetic correlation for additive and non-additive genetic effects, as well as a shared household effect. Here we conduct a series of bivariate genetic analyses in extended twin pedigree data on lifetime major depressive disorder (MDD) and three indicators of lifestyle, namely smoking behavior, physical inactivity, and obesity, decomposing phenotypic variance and covariance into genetic and environmental components. We analyze lifetime MDD and lifestyle data in a large multigenerational dataset of 19,496 individuals by variance component analysis in the 'Mendel' software. We find genetic correlations for MDD and smoking behavior (rG = 0.249), physical inactivity (rG = 0.161), body-mass index (rG = 0.081), and obesity (rG = 0.155), which were primarily driven by additive genetic effects. These outcomes provide evidence in favor of a shared genetic etiology between MDD and the lifestyle factors.
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Trastorno Depresivo Mayor/genética , Estilo de Vida , Gemelos Monocigóticos/genética , Adulto , Anciano , Trastorno Depresivo Mayor/epidemiología , Ejercicio Físico , Femenino , Pleiotropía Genética , Humanos , Masculino , Persona de Mediana Edad , Obesidad/epidemiología , Linaje , Fumar/epidemiología , Gemelos Monocigóticos/psicologíaRESUMEN
The ability to flexibly adapt thoughts and actions in a goal-directed manner appears to rely on cognitive control mechanisms that are strongly impacted by individual differences. A powerful research strategy for investigating the nature of individual variation is to study monozygotic (identical) twins. Evidence of twin effects have been observed in prior behavioral and neuroimaging studies, yet within the domain of cognitive control, it remains to be demonstrated that the neural underpinnings of such effects are specific and reliable. Here, we utilize a multi-task, within-subjects event-related neuroimaging design with functional magnetic resonance imaging to investigate twin effects through multivariate pattern similarity analyses. We focus on fronto-parietal brain regions exhibiting consistently increased activation associated with cognitive control demands across four task domains: selective attention, context processing, multi-tasking, and working memory. Healthy young adult monozygotic twin pairs exhibited increased similarity of within- and cross-task activation patterns in these fronto-parietal regions, relative to unrelated pairs. Twin activation pattern similarity effects were clearest under high control demands, were not present in a set of task-unrelated parcels or due to anatomic similarity, and were primarily observed during the within-trial timepoints in which the control demands peaked. Together, these results indicate that twin similarity in the neural representation of cognitive control may be domain-general but also functionally and temporally specific in relation to the level of control demand. The findings suggest a genetic and/or environmental basis for individual variation in cognitive control function, and highlight the potential of twin-based neuroimaging designs for exploring heritability questions within this domain.
Asunto(s)
Cognición/fisiología , Lóbulo Frontal/fisiología , Lóbulo Parietal/fisiología , Desempeño Psicomotor/fisiología , Gemelos Monocigóticos/genética , Adulto , Femenino , Lóbulo Frontal/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Lóbulo Parietal/diagnóstico por imagen , Test de Stroop , Gemelos Monocigóticos/psicologíaRESUMEN
Self-esteem is an attitude about the self that predicts psychopathology and general well-being. Parenting practices have been shown to be related to self-esteem, but these estimates are confounded because parents and children share genes. The aim of the present study was to use the monozygotic (MZ) twin difference design to isolate the non-shared environmental impact of remembered parenting on self-esteem. In a sample of 1328 adults (345 MZ twin pairs, 319 DZ twin pairs), retrospective reports of maternal and paternal affection were related to self-esteem, all of which were significantly heritable. Using MZ difference scores, paternal affection differences, but not maternal affection differences, were significantly related to self-esteem differences. These results suggest that parenting provided by the father directly impacts self-esteem through non-shared environmental mechanisms. Maternal affection, on the other hand, impacts self-esteem through shared genes (not shared environment, as shared environment was not a significant aspect of self-esteem). This has implications for parenting intervention programs.
Asunto(s)
Responsabilidad Parental/psicología , Conducta Paterna/psicología , Autoimagen , Adulto , Actitud , Bases de Datos Factuales , Ambiente , Femenino , Humanos , Masculino , Conducta Materna/psicología , Relaciones Padres-Hijo , Padres/psicología , Estudios Retrospectivos , Gemelos Dicigóticos/genética , Gemelos Monocigóticos/genética , Gemelos Monocigóticos/psicología , Estados UnidosRESUMEN
BACKGROUND: The rise of social media use in young people has sparked concern about the impact of cyber-victimisation on mental health. Although cyber-victimisation is associated with mental health problems, it is not known whether such associations reflect genetic and environmental confounding. METHODS: We used the co-twin control design to test the direct association between cyber-victimisation and multiple domains of mental health in young people. Participants were 7708 twins drawn from the Twins Early Development Study, a UK-based population cohort followed from birth to age 22. RESULTS: Monozygotic twins exposed to greater levels of cyber-victimisation had more symptoms of internalising, externalising and psychotic disorders than their less victimised co-twins at age 22, even after accounting for face-to-face peer victimisation and prior mental health. However, effect sizes from the most stringent monozygotic co-twin control analyses were decreased by two thirds from associations at the individual level [pooled ß across all mental health problems = 0.06 (95% CI 0.03-0.10) v. 0.17 (95% CI 0.15-0.19) in individual-level analyses]. CONCLUSIONS: Cyber-victimisation has a small direct association with multiple mental health problems in young people. However, a large part of the association between cyber-victimisation and mental health is due to pre-existing genetic and environmental vulnerabilities and co-occurring face-to-face victimisation. Therefore, preventative interventions should target cyber-victimisation in conjunction with pre-existing mental health vulnerabilities and other forms of victimisation.
Asunto(s)
Víctimas de Crimen/psicología , Ciberacoso/psicología , Trastornos Mentales/epidemiología , Trastornos Mentales/psicología , Gemelos Monocigóticos/psicología , Adulto , Víctimas de Crimen/estadística & datos numéricos , Ciberacoso/estadística & datos numéricos , Femenino , Humanos , Masculino , Medios de Comunicación Sociales , Encuestas y Cuestionarios , Reino Unido , Adulto JovenRESUMEN
Impulsivity and compulsivity are traits relevant to a range of mental health problems and have traditionally been conceptualised as distinct constructs. Here, we reconceptualised impulsivity and compulsivity as partially overlapping phenotypes using a bifactor modelling approach and estimated heritability for their shared and unique phenotypic variance within a classical twin design. Adult twin pairs (N = 173) completed self-report questionnaires measuring psychological processes related to impulsivity and compulsivity. We fitted variance components models to three uncorrelated phenotypic dimensions: a general impulsive-compulsive dimension; and two narrower phenotypes related to impulsivity and obsessiveness.There was evidence of moderate heritability for impulsivity (A2 = 0.33), modest additive genetic or common environmental effects for obsessiveness (A2 = 0.25; C2 = 0.23), and moderate effects of common environment (C2 = 0.36) for the general dimension, This general impulsive-compulsive phenotype may reflect a quantitative liability to related mental health disorders that indexes exposure to potentially modifiable environmental risk factors.
Asunto(s)
Conducta Compulsiva/genética , Fenotipo , Gemelos Dicigóticos/genética , Gemelos Dicigóticos/psicología , Gemelos Monocigóticos/genética , Gemelos Monocigóticos/psicología , Adolescente , Adulto , Femenino , Predisposición Genética a la Enfermedad , Humanos , Masculino , Persona de Mediana Edad , Modelos Estadísticos , Trastorno Obsesivo Compulsivo/genética , Factores de Riesgo , Autoinforme , Adulto JovenRESUMEN
We examined the item properties of the Two Peas Questionnaire (TPQ) among a sample of same-sex twin pairs from the Washington State Twin Registry. With the exception of the 'two peas' item, three of the mistakenness items showed differential item functioning. Results showed that the monozygotic (MZ) and dizygotic (DZ) pairs may differ in their responses on these items, even among those with similar latent traits of similarity and confusability. Upon comparing three classification methods to determine the zygosity of same-sex twins, the overall classification accuracy rate was over 90% using the unit-weighted pair zygosity sum score, providing an efficient and sufficiently accurate zygosity classification. Given the inherent nature of twin-pair similarity, the TPQ is more accurate in the identification of MZ than DZ pairs. We conclude that the TPQ is a generally accurate, but by no means infallible, method of determining zygosity in twins who have not been genotyped.