Psychobiological sequelae of cumulative exposure to violence: The Environmental Risk Longitudinal Twin Study
Lead Research Organisation:
King's College London
Department Name: Social Genetic and Dev Psychiatry Centre
Abstract
We propose to examine the hypothesis that being exposed to violence in childhood and adolescence increase individuals? risk of poor mental and physical health already in early adult life. Specifically, we will test whether young people who suffer violence exposure (physical or sexual maltreatment, witnessing parental domestic violence, bullying victimisation, assaults) will, by their entry to young adulthood at age 18, show signs of risks for developing diseases in later life.
We will test this hypothesis in the context of the Environmental Risk (E-Risk) Longitudinal Twin Study, a longitudinal study from birth to age 18 of twin children growing up in Britain. Here we propose to assess the cohort again at age 18, for new data collection. Each cohort member?s history of exposure to violence will be defined using data from repeated home-visit assessments of exposure to physical maltreatment, sexual abuse, bullying, parents? domestic violence, dating violence and assault victimisation across multiple years. We will assess the twins? perceptions of their violence exposure, as well as measures of risks for diseases later in later life: a) psychiatric syndromes, b) neuropsychological tests of working memory, executive functions and reaction times, c) telomere erosion, d) obesity and inflammation biomarkers, e) DNA methylation profiles and f) expression of selected genes. We selected these markers because they are thought to be sensitive to stress and are early warning signs for adult physical and psychiatric diseases.
The hope of preventing diseases and of increasing health expectancy requires research to identify candidate risk targets that can be tackled successfully in early life. If the hypothesis that exposure to violence in childhood and adolescence leaves marks on the mind and body in early adult life was shown to be true by our proposed research, this would imply that the burden of adult disease could be reduced by successfully treating early, before becoming a disease, conditions in children exposed to stress early in life.
We will test this hypothesis in the context of the Environmental Risk (E-Risk) Longitudinal Twin Study, a longitudinal study from birth to age 18 of twin children growing up in Britain. Here we propose to assess the cohort again at age 18, for new data collection. Each cohort member?s history of exposure to violence will be defined using data from repeated home-visit assessments of exposure to physical maltreatment, sexual abuse, bullying, parents? domestic violence, dating violence and assault victimisation across multiple years. We will assess the twins? perceptions of their violence exposure, as well as measures of risks for diseases later in later life: a) psychiatric syndromes, b) neuropsychological tests of working memory, executive functions and reaction times, c) telomere erosion, d) obesity and inflammation biomarkers, e) DNA methylation profiles and f) expression of selected genes. We selected these markers because they are thought to be sensitive to stress and are early warning signs for adult physical and psychiatric diseases.
The hope of preventing diseases and of increasing health expectancy requires research to identify candidate risk targets that can be tackled successfully in early life. If the hypothesis that exposure to violence in childhood and adolescence leaves marks on the mind and body in early adult life was shown to be true by our proposed research, this would imply that the burden of adult disease could be reduced by successfully treating early, before becoming a disease, conditions in children exposed to stress early in life.
Technical Summary
BACKGROUND: We propose to test the hypothesis that a history of violence exposure in early life increases individuals? risk of compromised psychobiological health, thereby mediating the pathway from stress in childhood to physical and mental illnesses in adulthood. Using innovative approaches, we will test whether young people who suffer violence exposure will show already by age 18 psychiatric symptoms, mild neuropsychological deficits and abnormal status of biomarkers that are considered to be prognostic for adult diseases.
METHOD: We will test this hypothesis in the Environmental Risk (E-Risk) Longitudinal Twin Study, a longitudinal study from birth to age 18 of a cohort of twin children growing up in Britain (N=2232 children). We propose to assess the cohort at age 18, for new data collection. Each cohort member?s history of violence exposure will be defined using prospectively-collected data from repeated home-visit assessments of exposure to physical maltreatment, sexual abuse, bullying, parents? domestic violence, dating violence and assault victimisation across multiple years. We will assess the twins? perceptions of their violence exposure and sensitive outcome measures of psychobiological status that are known predictors of diseases in later life: a) psychiatric syndromes, b) neuropsychological tests of working memory, executive functions and reaction times, c) telomere erosion, d) obesity and inflammation biomarkers, e) DNA methylation profiles and f) expression of selected genes. We will compare exposed children to non-exposed controls on psychobiological outcomes, and we will also test for dimensional associations between the frequency/severity of violence exposure and psychobiological outcomes. A unique design feature of the E-Risk Study is that baseline assessments of psychobiological status were carried out from birth to age 12, which can be used to test whether such status has changed in individuals exposed to violence in the interim years. Furthermore, our twin study offers a special design advantage, because twin siblings discordant for violence exposure can be compared to rule out other effects on psychobiological outcomes.
INNOVATION AND SIGNIFICANCE: The hope of preventing diseases and of increasing health expectancy requires research to identify candidate risk targets that can be tackled successfully, in early life. If the hypothesis that stress has psychobiological sequelae in early adult life was shown to be true by our proposed research, this would imply that the burden of adult disease could be reduced by successfully treating early, at a pre-clinical stage, psychobiological conditions in children exposed to stress early in life.
METHOD: We will test this hypothesis in the Environmental Risk (E-Risk) Longitudinal Twin Study, a longitudinal study from birth to age 18 of a cohort of twin children growing up in Britain (N=2232 children). We propose to assess the cohort at age 18, for new data collection. Each cohort member?s history of violence exposure will be defined using prospectively-collected data from repeated home-visit assessments of exposure to physical maltreatment, sexual abuse, bullying, parents? domestic violence, dating violence and assault victimisation across multiple years. We will assess the twins? perceptions of their violence exposure and sensitive outcome measures of psychobiological status that are known predictors of diseases in later life: a) psychiatric syndromes, b) neuropsychological tests of working memory, executive functions and reaction times, c) telomere erosion, d) obesity and inflammation biomarkers, e) DNA methylation profiles and f) expression of selected genes. We will compare exposed children to non-exposed controls on psychobiological outcomes, and we will also test for dimensional associations between the frequency/severity of violence exposure and psychobiological outcomes. A unique design feature of the E-Risk Study is that baseline assessments of psychobiological status were carried out from birth to age 12, which can be used to test whether such status has changed in individuals exposed to violence in the interim years. Furthermore, our twin study offers a special design advantage, because twin siblings discordant for violence exposure can be compared to rule out other effects on psychobiological outcomes.
INNOVATION AND SIGNIFICANCE: The hope of preventing diseases and of increasing health expectancy requires research to identify candidate risk targets that can be tackled successfully, in early life. If the hypothesis that stress has psychobiological sequelae in early adult life was shown to be true by our proposed research, this would imply that the burden of adult disease could be reduced by successfully treating early, at a pre-clinical stage, psychobiological conditions in children exposed to stress early in life.