Severity of personality disorder is an important determinant of future health. However, this key prognostic variable is not captured in routine clinical practice. Using a large clinical data-set, we explored the predictive validity of items from the Health of Nation Outcome Scales (HoNOS) as potential indicators of personality disorder severity. For 6912 patients with a personality disorder diagnosis, we examined associations between HoNOS items relating to core personality disorder symptoms (self-harm, difficulty in interpersonal relationships, performance of occupational and social roles, and agitation and aggression) and future health service use. Compared with those with no self-harm problem, the total healthcare cost was 2.74 times higher (95% CI 1.66–4.52; P < 0.001) for individuals with severe to very severe self-harm problems. Other HoNOS items did not demonstrate clear patterns of association with service costs. Self-harm may be a robust indicator of the severity of personality disorder, but further replication work is required.

Early signs of anger and aggression can be identified in infancy. Our aim was to use person-centered methods to identify which infants were most at risk for clinically significant behavioral problems by age 3 and diagnoses of ODD/CD by 7 years, while considering the role of family risk factors and positive parenting. A representative British community sample of 304 infants was assessed by multiple informants at mean ages of 6, 21, and 36 months of age. Latent Transition Analysis (LTA) identified three ordered subgroups at each age, with one subgroup (18%) displaying high levels of physical force as well as anger. These angry aggressive infants were at elevated risk for behavioral problems in early childhood and diagnoses of conduct disorder (CD) and/or oppositional defiant disorder (ODD) at 7 years of age. After other risk factors were taken into account, parents' beliefs in warm parenting and their observed positive affect while interacting with their infants were protective factors. These findings indicate the significance of very early manifestations of angry aggressiveness and have relevance for developmental theories of aggression and prevention strategies.

The Children of the Twins Early Development Study (CoTEDS) is a new prospective children-of-twins study in the UK, designed to investigate intergenerational associations across child developmental stages. CoTEDS will enable research on genetic and environmental factors that underpin parent–child associations, with a focus on mental health and cognitive-related traits. Through CoTEDS, we will have a new lens to examine the roles that parents play in influencing child development, as well as the genetic and environmental factors that shape parenting behavior and experiences. Recruitment is ongoing from the sample of approximately 20,000 contactable adult twins who have been enrolled in the Twins Early Development Study (TEDS) since infancy. TEDS twins are invited to register all offspring to CoTEDS at birth, with 554 children registered as of May 2019. By recruiting the second generation of TEDS participants, CoTEDS will include information on adult twins and their offspring from infancy. Parent questionnaire-based data collection is now underway for 1- and 2-year-old CoTEDS infants, with further waves of data collection planned. Current data collection includes the following primary constructs: child mental health, temperament, language and cognitive development; parent mental health and social relationships; parenting behaviors and feelings; and other socioecological factors. Measurement tools have been selected with reference to existing genetically informative cohort studies to ensure overlap in phenotypes measured at corresponding stages of development. This built-in study overlap is intended to enable replication and triangulation of future analyses across samples and research designs. Here, we summarize study protocols and measurement procedures and describe future plans.

We tested the hypothesis that high activity levels in infancy would predict self-regulatory problems and later symptoms of attention deficit and hyperactivity disorder (ADHD) in a longitudinal study of British families (N = 321). Infants’ activity levels were assessed at 6 months, using 3 informants’ reports from the Infant Behavior Questionnaire (IBQ) and ActiGraphs during baseline, attention, and restraint tasks. At a mean of 33 months, the children were assessed on self-regulatory tasks; at a mean of 36 months, 3 informants reported symptoms of ADHD. At a mean of 7.0 years, the children were assessed on executive function tasks; 3 informants reported on the child's symptoms of ADHD; and diagnoses of disorder were obtained using the Preschool Age Psychiatric Assessment. Informants’ reports of high activity levels at 6 months predicted ADHD symptoms in early childhood and diagnoses of ADHD with clinical impairment at age 7. The IBQ activity scale was also associated with the children's later performance on self-regulation tasks in early and middle childhood. Activity level in infancy reflects normal variation and is not a sign of psychopathology; however, these findings suggest that further study of the correlates of high activity level in infancy may help identify those children most at risk for disorder.

Quantitative and molecular genetic research requires large samples to provide adequate statistical power, but it is expensive to test large samples in person, especially when the participants are widely distributed geographically. Increasing access to inexpensive and fast Internet connections makes it possible to test large samples efficiently and economically online. Reliability and validity of Internet testing for cognitive ability have not been previously reported; these issues are especially pertinent for testing children. We developed Internet versions of reading, language, mathematics and general cognitive ability tests and investigated their reliability and validity for 10- and 12-year-old children. We tested online more than 2500 pairs of 10-year-old twins and compared their scores to similar internet-based measures administered online to a subsample of the children when they were 12 years old (> 759 pairs). Within 3 months of the online testing at 12 years, we administered standard paper and pencil versions of the reading and mathematics tests in person to 30 children (15 pairs of twins). Scores on Internet-based measures at 10 and 12 years correlated .63 on average across the two years, suggesting substantial stability and high reliability. Correlations of about .80 between Internet measures and in-person testing suggest excellent validity. In addition, the comparison of the internet-based measures to ratings from teachers based on criteria from the UK National Curriculum suggests good concurrent validity for these tests. We conclude that Internet testing can be reliable and valid for collecting cognitive test data on large samples even for children as young as 10 years.

We report the quasistatic tensile and impact penetration properties (falling dart test) of injection-molded polycarbonate samples, as a function of multiwall carbon nanotube (MWNT) concentration (0.0–2.5%). The MWNT were incorporated by dilution of a commercial MWNT/polycarbonate masterbatch. The stiffness and quasistatic yield strength of the composites increased approximately linearly with MWNT concentration in all measurements. The energy absorbed in fracture was, however, a negative function of the MWNT concentration, and exhibited different dependencies in quasistatic and impact tests. Small-angle x-ray scattering (SAXS) showed that the dispersion of the MWNT was similar at all concentrations. The negative effects on energy absorption are attributed to agglomerates remaining in the samples, which were observed in optical microscopy and SAXS. Overall, there was a good correspondence between static and dynamic energy absorption.

We investigated infant precursors of low language scores in early childhood. The sample included 373 probands in 130 monozygotic (MZ) and 109 same-sex dizygotic (DZ) twin pairs in which at least one member of the pair scored in the lowest 15th percentile of a control sample on a general language factor derived from tester-administered tests at 4;6. From data at 2;0, 3;0 and 4;0 the antecedents of poor language performance at 4;6 for these probands were compared to 290 control children. As early as 2;0, language measures substantially predicted low-language status at 4;6, with predictions increasing at 3;0 and 4;0. Nonverbal cognitive development at 3;0 and 4;0 was nearly as predictive of low language at 4;6 as were the language measures. Behaviour problems were also significant predictors of low language status although the associations were only about half as strong. Bivariate genetic analyses indicated that these predictions are mediated by both genetic and shared environmental links.