L. J. Horwood

Prevalence of traumatic brain injury among children, adolescents and young adults: Prospective evidence from a birth cohort

Background: Little is known about the incidence and prevalence of traumatic brain injury (TBI), particularly for infants, children and young adults. Primary objective: The purpose of this study was to provide an accurate estimate of the incidence and prevalence of TBIs for individuals between 0–25 years of age. Method and procedures: A birth cohort of 1265 individuals was used, for which information regarding TBI events, both hospitalized and non-hospitalized, had been recorded. Main outcomes and results: The average incidence for this age group ranged from 1.10–2.36 per 100 per year, with an overall prevalence of ∼30%. The most common source of injury was falls for individuals 0–14 years of age and contact sports and motor vehicle accidents for 15–25 year olds. Approximately one third of the individuals who experienced a TBI went on to have one or more additional injuries. Conclusions: The incidence rates reported here are much higher than those previously found. It is clear that TBIs constitute a major health issue and therefore it is important to have accurate information to enable planning for primary healthcare services and to inform prevention programmes.

Long-term behavioural outcomes of pre-school mild traumatic brain injury.

Abstract Background Mild traumatic brain injury (MTBI) is a leading cause of injury for children during their pre-school years. However, there is little information regarding the long-term outcomes of these injuries. Method We used fully prospective data from an epidemiological study of a birth cohort to examine behavioural effects associated with MTBI during the pre-school years. Cases of confirmed MTBI were divided into two groups, those that had received outpatient medical attention, and those that had been admitted to hospital for a brief period of observation (inpatient cases). The remainder of the cohort served as a reference control group. Results Mother/teacher ratings for behaviours associated with attention deficit/hyperactivity disorder and oppositional defiant/conduct disorder, obtained yearly from age 7 to 13, revealed evidence of deficits after inpatient MTBI (n = 21), relative to more minor outpatient injury MTBI (n = 55) and the reference control group (n = 852). For the inpatient group there was evidence of increasing deficits over years 7-13. Conclusions More severe pre-school MTBI may be associated with persistent negative effects in terms of psychosocial development. The vulnerability of pre-school children to MTBI signals a pressing need to identify high-risk cases that may benefit from monitoring and early intervention.

Cigarette smoking and suicidal behaviour: results from a 25-year longitudinal study

BACKGROUNDnThis study examined the associations between cigarette smoking and suicidal ideation and suicide attempts, both before and after control for potentially confounding using fixed effects regression models.nnnMETHODnData were gathered during the Christchurch Health and Development Study, a 25-year longitudinal study of a birth cohort of New Zealand children (635 males, 630 females). The analysis was based on a sample of 1041 participants with available data on cigarette smoking and suicidal behaviour from ages 16 to 25 years. The main outcome measures were suicidal ideation and suicide attempts, ages 16-18, 18-21, and 21-25.nnnRESULTSnThere were significant bivariate associations between the frequency of cigarette smoking and both suicidal ideation and suicide attempts. Cohort members who smoked 20 or more cigarettes per day had odds of suicidal ideation that were 3.39 times (95% CI 2.06-5.59) those of non-smokers, and odds of suicide attempt that were 4.39 (95% CI 2.18-8.85) times those of non-smokers. Control for non-observed fixed confounding factors reduced the association between cigarette smoking and suicidal ideation and suicide attempts to statistical non-significance. After adjustment, those smoking more than 20 cigarettes per day had odds of suicidal ideation that were 1.00 times (95% CI 0.46-2.18) those of non-smokers, and odds of suicide attempt that were 1.84 (95% CI 0.81-4.18) times those of non-smokers.nnnCONCLUSIONSnThe findings suggest that the associations between frequency of cigarette smoking and suicidal behaviour may largely be explained by the non-observed background factors and life circumstances that are associated with both cigarette smoking and suicidal behaviour.

An investigation of the pre-injury risk factors associated with children who experience traumatic brain injury

Background and Objective Traumatic brain injury (TBI) is a frequently occurring event in childhood that may have significant ongoing effects. Little is known about the child and family characteristics that predispose children to these injuries. A greater understanding of the risk factors associated with childhood TBI may provide an opportunity to prevent their occurrence. Methods Information provided by a large birth cohort study (n=1265) was used to determine the child and family risk factors of TBI in children aged 0–15 years (n=187). All information regarding child, family, and injury events were collected prospectively and unrelated to the injury event itself. Child variables included in the analysis were sex and the level of behavioural problems. Parental variables included were family socioeconomic status, mothers age, education level, depressive symptoms, number of adverse life events experienced by the family, and parenting style. Results The most important risk factors were sex, adverse life events, and parenting style. The results suggest evidence of modest increases in the rate of TBI for those in the highest risk categories (male, ≥4 life events per annum, high maternal punitiveness) compared to the lowest risk categories, with hazard ratios in the region of 1.4–1.6. Conclusions Overall characteristics of both the family and child predicted a TBI event. An increased understanding of risks associated with TBI in childhood will provide an avenue to prevent these injuries by targeting at-risk families and aiding the development of appropriate intervention strategies.

Childhood exposure to sexual abuse and partnership outcomes at age 30.

BACKGROUNDnIn this study, 30-year longitudinal data from the Christchurch Health and Development Study (CHDS) were used to examine the associations between childhood exposure to sexual abuse and intimate relationship outcomes at age 30. In addition, a broad range of early childhood and family confounding factors were tested, and the role of intervening factors from adolescence was explored.nnnMETHODnThe investigation analyzed data from a birth cohort of over 900 New Zealand adults studied to the age of 30. At ages 18 and 21 cohort members reported on any exposure to sexual abuse prior to age 16. This information, along with prospective data gathered in childhood and adolescence, was used to predict partnership outcomes at age 30.nnnRESULTSnAfter adjustment for early childhood and family factors, exposure to more severe forms of childhood sexual abuse (CSA) was associated with earlier and more frequent cohabitation, higher rates of perpetrated interpartner violence (IPV), and early parenthood, lower relationship satisfaction and investment. Several factors from adolescence partially or fully mediated these associations, notably a history of early consensual sexual intercourse, higher number of sexual partnerships, substance abuse problems, and self-esteem. After adjustment for intervening factors, exposure to CSA remained significantly associated with IPV.nnnCONCLUSIONSnThe findings support a causal chain process, whereby early childhood and family factors place some individuals at risk for CSA. The extent of CSA exposure is related to adolescent risk taking, which in turn leads to early and more frequent cohabitation, risk of IPV, and lower relationship satisfaction and investment.

Adolescent depression, adult mental health and psychosocial outcomes at 30 and 35 years

BACKGROUNDnThere is limited information on long-term outcomes of adolescent depression. This study examines the associations between severity of depression in adolescence and a broad array of adult functional outcomes.nnnMETHODnData were gathered as part of the Christchurch Health and Development Study, a 35-year longitudinal study of a birth cohort of 1265 children born in Christchurch, New Zealand in 1977. Severity of depression at age 14-16 years was classified into three levels according to DSM symptom criteria for major depression (no depression/sub-threshold symptoms/major depression). This classification was related to adult functional outcomes assessed at ages 30 and 35 years using a generalized estimating equation modeling approach. Outcome measures spanned domains of mental disorder, education/economic circumstances, family circumstances and partner relationships.nnnRESULTSnThere were modest but statistically significant bivariate associations between adolescent depression severity and most outcomes. After covariate adjustment there remained weak but significant (p < 0.05) associations with rates of major depression, anxiety disorder, illicit substance abuse/dependence, any mental health problem and intimate partner violence (IPV) victimization. Estimates of attributable risk for these outcomes ranged from 3.8% to 7.8%. For two outcomes there were significant (p < 0.006) gender interactions such that depression severity was significantly related to increased rates of unplanned pregnancy and IPV victimization for females but not for males.nnnCONCLUSIONSnThe findings reinforce the importance of the individual/family context in which adolescent depression occurs. When contextual factors and probable maturational effects are taken into account the direct effects of adolescent depression on functioning in mature adulthood appear to be very modest.

Life satisfaction and mental health problems (18 to 35 years).

BACKGROUNDnPrevious research has found that mental health is strongly associated with life satisfaction. In this study we examine associations between mental health problems and life satisfaction in a birth cohort studied from 18 to 35 years.nnnMETHODnData were gathered during the Christchurch Health and Development Study, which is a longitudinal study of a birth cohort of 1265 children, born in Christchurch, New Zealand, in 1977. Assessments of psychiatric disorder (major depression, anxiety disorder, suicidality, alcohol dependence and illicit substance dependence) using DSM diagnostic criteria and life satisfaction were obtained at 18, 21, 25, 30 and 35 years.nnnRESULTSnSignificant associations (p < 0.01) were found between repeated measures of life satisfaction and the psychiatric disorders major depression, anxiety disorder, suicidality, alcohol dependence and substance dependence. After adjustment for non-observed sources of confounding by fixed effects, statistically significant associations (p < 0.05) remained between life satisfaction and major depression, anxiety disorder, suicidality and substance dependence. Overall, those reporting three or more mental health disorders had mean life satisfaction scores that were nearly 0.60 standard deviations below those without mental health problems. A structural equation model examined the direction of causation between life satisfaction and mental health problems. Statistically significant (p < 0.05) reciprocal associations were found between life satisfaction and mental health problems.nnnCONCLUSIONSnAfter adjustment for confounding, robust and reciprocal associations were found between mental health problems and life satisfaction. Overall, this study showed evidence that life satisfaction influences mental disorder, and that mental disorder influences life satisfaction.

Cognitive Development Trajectories of Very Preterm and Typically Developing Children

Cognitive impairment is common among children born very preterm (VPT), yet little is known about how this risk changes over time. To examine this issue, a regional cohort of 110 VPT (≤xa032xa0weeks gestation) and 113 full-term (FT) born children was prospectively assessed at ages 4, 6, 9, and 12xa0years using the Wechsler Preschool and Primary Scale of Intelligence-Revised and then Wechsler Intelligence Scale for Children, 4th ed. At all ages, VPT children obtained lower scores than their FT born peers (pxa0<xa0.001). Growth curve modeling revealed stable cognitive trajectories across both groups. Neonatal white matter abnormalities and family socioeconomic adversity additively predicted cognitive risk. Despite some intraindividual variability, cognitive functioning of typically developing and high-risk VPT children was stable and influenced by early neurological development and family rearing context.

Bullying victimization in adolescence and psychotic symptomatology in adulthood: evidence from a 35-year study

BACKGROUNDnThere has been considerable recent interest in possible causal linkages between exposure to bullying victimization and later psychotic symptomatology. Prior research in this area has had several limitations which make it difficult to ascertain causality, and to determine the extent to which these effects extend beyond adolescence.nnnMETHODnData were obtained from the Christchurch Health and Development Study, a 35-year study of a longitudinal birth cohort. This investigation used generalized estimating equation modelling to estimate the associations between bullying victimization (ages 13-16 years) and psychotic symptoms (ages 18-35 years), before and after controlling for possible confounding factors, including: gender; childhood socio-economic status; child intelligence quotient; exposure to sexual abuse in childhood; anxious/withdrawn behaviour and attention problems (ages 7-9 years); and adolescent psychotic symptoms and paranoid ideation (ages 15-16 years).nnnRESULTSnThere was a significant (p < 0.0001) bivariate association between bullying victimization in adolescence and psychotic symptomatology in adulthood. Successive models controlling for covariation reduced this association to statistical non-significance. After controlling for covariates, those with the highest level of bullying victimization had rates of psychotic symptoms that were 1.21 (95% confidence interval 0.73-1.99) times higher than those who were not victimized.nnnCONCLUSIONSnThe association between bullying victimization in adolescence and psychotic symptomatology in adulthood could be largely explained by childhood behavioural problems, and exposure to sexual abuse in childhood. The results suggest that bullying victimization was unlikely to have been a cause of adult psychotic symptoms, but bullying victimization remained a risk marker for these symptoms.

Cumulative mental health consequences of acne: 23-year follow-up in a general population birth cohort study.

DEAR EDITOR, Acne is a highly prevalent condition during adolescence and young adulthood worldwide, with rates between 12% and 99%. Rates in adulthood range up to 50%. The effects of acne, regardless of severity, can be debilitating, affecting many life domains. Cross-sectional studies report associations between acne and anxiety, depression symptoms and suicide ideation compared with those having little or no acne. However, no study has examined the relationship of acne with psychiatric disorder (i.e. psychological distress of greatest severity and clinical interest), nor has research ascertained the cumulative life course effects of acne on psychiatric disorder. Here, we report data from a prospective-longitudinal study of a general population sample to determine whether acne preceded poor mental health at the disorder level, from adolescence to adulthood. The specific aim of this study was to examine the association between acne and the development of the most common psychiatric disorders of anxiety, depression, alcohol and cannabis dependence. Data were from the Dunedin Multidisciplinary Health and Development Study, a longitudinal investigation of the health, development and behaviour of a general population birth cohort. Study participants were born between April 1972 and March 1973 in Dunedin, New Zealand. The cohort represents the full range of socioeconomic status in the general population of New Zealand’s South Island and is primarily white. The longitudinal study was established at age three when those who were still resident in the province were followed up, and 91% (n = 1037; 52% male) participated. Subsequent assessments took place at ages 5 (96% of those alive participated), 7 (92%), 9 (92%), 11 (90%), 13 (82%), 15 (95%), 18 (97%), 21 (97%), 26 (97%) and 32 (96%), and most recently at 38 years, when 95% participated. At each age, a range of physical, mental and psychosocial measures were assessed on site by professional staff trained in each of the domains. Ethical approval was obtained for each phase of the study. At all the assessments, professional staff with specific training in the relevant domains received further training standardized to protocol. Health professionals administered the general health interview (which included questions about acne) and the mental health interview. At the age 21 assessment, study participants were asked if, since age 15, they had ‘a bad problem acne’; this was repeated at the next three assessments, i.e. at age 26 for the period from 21 to 26 years, at age 32 (26– 32 years) and at age 38 (32–38 years). Mental health data were collected using the Diagnostic Interview Schedule, allowing disorder status to be made according to standardized Diagnostic and Statistical Manual of Mental Disorders criteria. Each disorder (anxiety, depression, alcohol dependence and cannabis dependence disorders) was diagnosed regardless of the presence of other disorders using the past year as the reporting period. Adjustment was made for potential confounders: sex, socioeconomic status and prior adolescent psychiatric disorder (11–18 years).