Timothy Matthews

Social Isolation and Mental Health at Primary and Secondary School Entry: A Longitudinal Cohort Study

Objective We tested whether children who are socially isolated early in their schooling develop mental health problems in early adolescence, taking into account their mental health and family risk at school entry. Method We used data from the Environmental Risk (E-Risk) Longitudinal Twin Study, a birth cohort of 2,232 children born in England and Wales in 1994 and 1995. We measured social isolation using mothers’ and teachers’ reports at ages 5 and 12 years. We assessed mental health symptoms via mothers’ and teachers’ ratings at age 5 and self-report measures at age 12. We collected mother-reported information about the family environment when children were 5 years old. We conducted regression analyses to test concurrent and longitudinal associations between early family factors, social isolation, and mental health difficulties. Results At both primary and secondary school, children who were socially isolated experienced greater mental health difficulties. Children with behavioral problems or attention-deficit/hyperactivity disorder (ADHD) symptoms at age 5 years had an elevated risk of becoming more socially isolated at age 12. However, children who were isolated at age 5 did not have greater mental health symptoms at age 12, over and above pre-existing difficulties. Conclusion Although social isolation and mental health problems co-occur in childhood, early isolation does not predict worse mental health problems later on. However, children who exhibit problematic behaviors may struggle to cope with the social challenges that accompany their progression through the early school years.

Childhood Bullying Victimization and Overweight in Young Adulthood: A Cohort Study

Objective To test whether bullied children have an elevated risk of being overweight in young adulthood and whether this association is: (1) consistent with a dose-response relationship, namely, its strength increases with the chronicity of victimization; (2) consistent across different measures of overweight; (3) specific to bullying and not explained by co-occurring maltreatment; (4) independent of key potential confounders; and (5) consistent with the temporal sequence of bullying preceding overweight. Method A representative birth cohort of 2,232 children was followed to age 18 years as part of the Environmental Risk Longitudinal Twin Study. Childhood bullying victimization was reported by mothers and children during primary school and early secondary school. At the age-18 follow-up, we assessed a categorical measure of overweight, body mass index, and waist-hip ratio. Indicators of overweight were also collected at ages 10 and 12. Co-twin body mass and birth weight were used to index genetic and fetal liability to overweight, respectively. Results Bullied children were more likely to be overweight than non-bullied children at age 18, and this association was (1) strongest in chronically bullied children (odds ratio = 1.69; 95% confidence interval [CI] = 1.21–2.35); (2) consistent across measures of overweight (body mass index: b = 1.12; 95% CI = 0.37–1.87; waist-hip ratio: b = 1.76; 95% CI = 0.84–2.69); (3) specific to bullying and not explained by co-occurring maltreatment; (4) independent of child socioeconomic status, food insecurity, mental health, and cognition, and pubertal development; and (5) not present at the time of bullying victimization, and independent of childhood weight and genetic and fetal liability. Conclusion Childhood bullying victimization predicts overweight in young adulthood.

Childhood victimization and inflammation in Young Adulthood: A Genetically Sensitive Cohort Study

Highlights • Childhood victimization predicted elevated levels of CRP at age 18.• The association between child victimization and CRP levels was specific to females.• Latent genetic influences on CRP levels did not explain the association in females.

ADHD and Sleep Quality: Longitudinal Analyses From Childhood to Early Adulthood in a Twin Cohort

Attention-deficit/hyperactivity disorder (ADHD) is associated with poor sleep quality, but there is more to learn about the longitudinal association and aetiology of this association. We investigated the following: (a) Is there an association between childhood ADHD and poor sleep quality in young adulthood? (b) Is this driven by the long-term effects of childhood ADHD or concurrent associations with ADHD in young adulthood? (c) To what extent do genetic and environmental influences explain the overlap between symptoms of ADHD and poor sleep quality? Participants were from the Environmental Risk Longitudinal Twin Study of 2,232 twin children born in the United Kingdom in 1994–1995. We ascertained ADHD diagnoses at ages 5, 7, 10, 12, and 18. We assessed sleep quality using the Pittsburgh Sleep Quality Index at age 18. We used regression models to examine longitudinal associations and bivariate twin modelling to test genetic and environmental influences. Children with ADHD had poorer sleep quality in young adulthood, but only if their ADHD persisted. Adults with ADHD had more sleep problems than those without ADHD, over and above psychiatric comorbidity and maternal insomnia. ADHD and sleep problems in young adulthood were associated because of genetic (55%) and nonshared environmental influences (45%). Should ADHD remit, children with ADHD do not appear to have an increased risk of later sleep problems. Good quality sleep is important for multiple areas of functioning, and a better understanding of why adults with ADHD have poorer sleep quality will further the goal of improving treatments.

Etiology of Pervasive versus Situational Antisocial Behaviors: A Multi-informant Longitudinal Cohort Study.

The aim of this study was to disentangle pervasive from situational antisocial behaviors using multiple informants, and to investigate their genetic and environmental etiologies in preadolescence and across time. Antisocial behaviors were assessed in 2,232 twins from the Environmental Risk (E‐Risk) Longitudinal Twin Study at ages 5 and 12. Pervasive antisocial behaviors were defined as behaviors that mothers, teachers, interviewers, and twins themselves agreed on. Results from a psychometric model indicated that the variation in childrens pervasive antisocial behaviors was mostly accounted for by familial influences that originated in childhood, whereas situational behaviors were explained by newly emerging nonshared environmental and genetic influences. This study shows that childrens pervasive and situational antisocial behaviors have distinct etiologies that could guide research and treatment.

Sleeping with one eye open: loneliness and sleep quality in young adults

Background Feelings of loneliness are common among young adults, and are hypothesized to impair the quality of sleep. In the present study, we tested associations between loneliness and sleep quality in a nationally representative sample of young adults. Further, based on the hypothesis that sleep problems in lonely individuals are driven by increased vigilance for threat, we tested whether past exposure to violence exacerbated this association. Method Data were drawn from the Environmental Risk (E-Risk) Longitudinal Twin Study, a birth cohort of 2232 twins born in England and Wales in 1994 and 1995. We measured loneliness using items from the UCLA Loneliness Scale, and sleep quality using the Pittsburgh Sleep Quality Index. We controlled for covariates including social isolation, psychopathology, employment status and being a parent of an infant. We examined twin differences to control for unmeasured genetic and family environment factors. Results Feelings of loneliness were associated with worse overall sleep quality. Loneliness was associated specifically with subjective sleep quality and daytime dysfunction. These associations were robust to controls for covariates. Among monozygotic twins, within-twin pair differences in loneliness were significantly associated with within-pair differences in sleep quality, indicating an association independent of unmeasured familial influences. The association between loneliness and sleep quality was exacerbated among individuals exposed to violence victimization in adolescence or maltreatment in childhood. Conclusions Loneliness is robustly associated with poorer sleep quality in young people, underscoring the importance of early interventions to mitigate the long-term outcomes of loneliness. Special care should be directed towards individuals who have experienced victimization.

Protective factors for psychotic experiences amongst adolescents exposed to multiple forms of victimization

Experiencing multiple types of victimization (poly-victimization) during adolescence is associated with the onset of psychotic experiences (such as hearing voices, having visions, or being extremely paranoid). However, many poly-victimized adolescents will not develop such subclinical phenomena and the factors that protect them are unknown. This study investigated whether individual, family, or community-level characteristics were associated with an absence of psychotic experiences amongst poly-victimized adolescents. Participants were from the Environmental Risk (E-Risk) Longitudinal Twin Study, a nationally-representative cohort of 2232 UK-born twins. Exposure to seven different types of victimization between ages 12–18 was ascertained using a modified version of the Juvenile Victimization Questionnaire at age 18. Adolescents were also interviewed about psychotic experiences at age 18. Protective factors were measured at ages 12 and 18. We found that exposure to poly-victimization during adolescence was associated with age-18 psychotic experiences (OR = 4.62, 95% CI 3.59–5.94, P < 0.001), but more than a third of the poly-victimized adolescents reported having no psychotic experiences (40.1%). Greater social support was found to be protective against adolescent psychotic experiences even amongst those exposed to poly-victimization. Engaging in physical activity and greater neighborhood social cohesion were also associated with a reduced likelihood of age-18 psychotic experiences in the whole sample, with non-significant trends in the poly-victimized group. Increasing social support and promoting physical activity appear to be important areas for future research into the development of preventive interventions targeting adolescent psychotic experiences. This adds further weight to calls to increase the promotion of these factors on a public health scale.

Associations between abuse/neglect and ADHD from childhood to young adulthood: A prospective nationally-representative twin study

Child maltreatment has consistently been found to be associated with attention deficit/hyperactivity disorder (ADHD). However, the robustness of this association and the direction of the link between maltreatment and ADHD remain unclear. We used data from the Environmental Risk (E-Risk) Longitudinal Twin Study, a cohort of 2232 British twins, to investigate the associations between exposure to abuse/neglect and ADHD in childhood and in young adulthood, and to test their robustness and specificity. We also aimed to test longitudinal associations between abuse/neglect and ADHD from childhood to young adulthood, controlling for confounders. Results indicated strong associations between abuse/neglect and ADHD in childhood and also in young adulthood. In childhood, the association was concentrated among children with comorbid conduct disorder. Longitudinal analyses showed that childhood ADHD predicted abuse/neglect in later years. This association was again concentrated among individuals with comorbid conduct disorder. Abuse/neglect in childhood was not associated with later ADHD in young adulthood after adjusting for childhood ADHD. Our study does not provide support of a causal link between child abuse/neglect and adult ADHD but highlights the possibility of a long-term effect of disruptive behaviors on the risk for experiencing abuse/neglect. These findings emphasize the need for clinicians treating people with ADHD, especially those with comorbid conduct disorder, to be aware of their increased risk for experiencing abuse/neglect. Interventions aimed at reducing risks of abuse/neglect should also focus on the environment of individuals with disruptive behaviors.