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Biomedical subjects

Jon Heron

Publications and source records attributed to Jon Heron.

16 recordsLinked to original sources
PubMed2007

Gender-specific effects of the catechol-O-methyltransferase Val108/158Met polymorphism on cognitive function in children.

OBJECTIVE: The study aimed to determine the cognitive effect of the Val108/158Met polymorphism in the catechol-O-methyltransferase (COMT) gene in children before and during puberty. This polymorphism affects cognitive function in healthy adults and may contribute to risk for schizophrenia. METHOD: COMT genotype was determined for 8,707 children from the Avon Longitudinal Study of Parents and Children (ALSPAC), a geographically defined general population cohort of children born between April 1, 1991, and Dec. 31, 1992, in the southwest of England. Fourteen measures of cognitive function--including working memory, verbal and motor inhibition, attentional control, and IQ--were assessed at ages 8 and 10 years. Any pubertal development at age 9 years was reported by parents. Effects of COMT genotype on cognition and interactions with gender and puberty were assessed using general linear models. RESULTS: In boys, genotype significantly affected executive function and explained up to 10 points normal variation in verbal IQ. The effects on IQ were significantly greater in pubertal than in prepubertal boys. In girls, there were no significant effects of genotype on cognition. CONCLUSIONS: This common polymorphism may be one of the genes of small effect that contribute to normal variation in IQ. The gender-specific nature of the effect and its possible interaction with puberty may be relevant to both normal cognitive and brain development and to abnormal development in disorders such as schizophrenia.

Adolescent↗
PubMed2006

Psychological problems in children with bedwetting and combined (day and night) wetting: A UK population-based study.

OBJECTIVE: To investigate the psychological problems associated with bedwetting and combined (day and night) wetting in children aged around 7(1/2) years. METHODS: Participants were a cohort of over 8000 children enrolled in the population-based Avon Longitudinal Study of Parents and Children. Parents completed postal questionnaires assessing common childhood psychological problems, and children were asked about behavior, friendships, bullying, and self-esteem in clinical interviews. The rates of psychological problems were compared in children with bedwetting, combined wetting, and in children with no wetting problems. RESULTS: The study found a higher rate of parent-reported psychological problems in children with bedwetting and combined wetting compared with those with no wetting problems. Children with combined wetting were particularly at risk for externalizing problems. There was little difference with the child-reported measures. CONCLUSIONS: Bedwetting and combined wetting are associated with parent-reported psychological problems and combined wetting confers an increased risk for externalizing problems.

Child↗
PubMed2006

Child maltreatment in the "children of the nineties": a cohort study of risk factors.

AIM: To analyze the multiple factors affecting the risk of maltreatment in young children within a comprehensive theoretical framework. METHODS: The research is based on a large UK cohort study, the Avon Longitudinal Study of Parents and Children. Out of 14,256 children participating in the study, 293 were investigated by social services for suspected maltreatment and 115 were placed on local child protection registers prior to their 6th birthday. Data on the children have been obtained from obstetric data and from a series of parental questionnaires administered during pregnancy and the first 3 years of life. Risk factors have been analyzed using an hierarchical approach to logistic regression analysis. RESULTS: In the stepwise hierarchical analysis, young parents, those with low educational achievement, and those with a past psychiatric history or a history of childhood abuse were all more likely to be investigated for maltreatment, or to have a child placed on the child protection register, with odds ratios between 1.86 and 4.96 for registration. Examining strength of effect, the highest risks were found with indicators of deprivation (3.24 for investigation and 11.02 for registration, after adjusting for parental background factors). Poor social networks increased the risk of both investigation (adjusted OR 1.93) and registration (adjusted OR 1.90). Maternal employment seemed to reduce the risk of both outcomes but adjusted odds ratios were no longer significant for registration. After adjusting for higher order confounders, single parents and reordered families were both at higher risk of registration. Reported domestic violence increased the risk of investigation and registration but this was no longer significant after adjusting for higher order variables. Low birthweight children were at higher risk of registration as were those whose parents reported few positive attributes of their babies. CONCLUSIONS: This study supports previous research in the field demonstrating that a wide range of factors in the parental background, socio-economic and family environments affect the risk of child maltreatment. By combining factors within a comprehensive ecological framework, we have demonstrated that the strongest risks are from socio-economic deprivation and from factors in the parents' own background and that parental background factors are largely, but not entirely, mediated through their impact on socio-economic factors.

Child↗
PubMed2006

Fetal growth and childhood behavioral problems: results from the ALSPAC cohort.

Using data on 4,813 children from the ALSPAC cohort in Bristol, United Kingdom, recontacted in 1998-1999, the authors investigated whether intrauterine growth restriction (indexed by birth weight and length) was associated with behavioral problems at age 7 years. Childhood behavioral problems were measured by using a brief behavioral screening questionnaire (the Strengths and Difficulties Questionnaire (parental completion)). For term singleton infants, a one standard deviation increase in birth weight was associated with an 11% reduction in the odds of behavioral problems at age 81 months. After adjustment for confounders and birth length, this association was no longer seen. The association with birth length remained after adjustment for confounders. A one standard deviation increase in birth length was associated with a 14% decrease in the odds of being in the top tertile of total behavioral difficulties at age 81 months (odds ratio = 0.86, 95% confidence interval: 0.79, 0.95) and was similarly associated with hyperactivity and conduct problems. Evidence was weak for an association between birth length and behavioral problems earlier in childhood. In summary, there was a weak association between intrauterine growth restriction, indexed by birth length (rather than weight), and childhood behavioral problems. Future work should focus on elucidating the biologic mechanisms that lead to variations in birth length and underlie this association.

Birth Weight↗
PubMed2006

Exploring the differences between mono- and polysymptomatic nocturnal enuresis.

OBJECTIVE: Recently the heterogeneity of nocturnal enuresis has been manifest in the distinction between mono- and polysymptomatic forms, based on the absence or presence of bladder overactivity, respectively. Although this classification has important clinical implications, there is a lack of empirical work relating to associated symptom expression and psychological functioning. The aim of this study was to identify variables associated with the two forms of nocturnal enuresis by means of a large population survey. MATERIAL AND METHODS: From a cohort of 11,021 parents surveyed as part of the Avon Longitudinal Study of Parents and Children when their children were aged 7(1/2) years, 8242 questionnaires were returned, with 7935 children meeting the inclusion criteria. Parents were invited to complete a questionnaire containing items relating to bedwetting, toileting behaviour, day-time wetting, bowel functioning and psychological variables. RESULTS: A total of 194 children met the Diagnostic and Statistical Manual of Mental Disorders-IV definition of nocturnal enuresis, of whom 133 (68.5%) were classified as monosymptomatic and 61 (31.5%) as polysymptomatic. Those with the polysymptomatic form were significantly more likely to have multiple episodes of bedwetting, to show signs (such as fidgeting) of needing to urinate during the day, to need a reminder to toilet during the day and to have day-time wetting and soiling. CONCLUSIONS: The proportion of mono- to polysymptomatic nocturnal enuresis was 2:1. Children with the polysymptomatic form had a number of associated bladder and bowel problems. Clinically it is important to distinguish between the two types of nocturnal enuresis in order to identify the most appropriate treatment intervention.

Child↗
PubMed2006

Psychological differences between children with and without soiling problems.

OBJECTIVES: Previous studies, based on clinic samples, report that childhood soiling is associated with behavior problems and reduced self-esteem. This population-based study investigates the prevalence of psychological problems associated with childhood soiling. METHODS: A total of 8242 children aged 7-8 years born to mothers in the United Kingdom-based Avon Longitudinal Study of Parents and Children were studied. Parents completed postal questionnaires assessing common childhood emotional and behavioral problems, and children were asked questions at a research clinic concerning their behavior, friendships, bullying, and self-esteem. The rate of psychological problems was compared in children who soil frequently (once a week or more), those who soil occasionally (less than once a week), and those with no soiling problems (controls). Analyses were adjusted for developmental delay, gender, sociodemographic background, and stressful life events. RESULTS: Children who soil were reported by their parents to have significantly more emotional and behavioral problems compared with children who do not soil. Children who soil frequently had significantly more problems than those who soil occasionally. The rate of attention and activity problems, obsessions and compulsions, and oppositional behavior was particularly high in frequently soiling children. Children with soiling problems reported significantly higher rates of involvement in overt bullying (as both perpetrator and victim) and antisocial activities compared with controls. CONCLUSIONS: The current study finds significantly higher rates of behavior and emotional problems, bullying, and antisocial activities in children who soil compared with those who do not soil. Children who soil frequently are more likely to have these problems than those who soil occasionally.

Aggression↗
PubMed2006

Psychological problems in children with daytime wetting.

OBJECTIVE: This population-based study investigated the psychological problems associated with daytime wetting in children. METHODS: A sample of 8213 children (age range: 7 years 6 months to 9 years 3 months) who were enrolled in the population-based Avon Longitudinal Study of Parents and Children participated in this study. Parents completed a postal questionnaire asking about their children's toileting behavior and assessing psychological problems, including childhood emotional and behavioral problems (99% completed the questionnaire by the time their child was 8 years 3 months of age). The rate of psychological problems was compared in children with daytime wetting and in those with no daytime wetting. Analyses adjusted for developmental delay, gender, sociodemographic background, stressful life events, and soiling. RESULTS: Chi2 tests of association and multivariable logistic regression indicate that children with daytime wetting have a higher rate of parent-reported psychological problems than children who have no daytime wetting. It is particularly notable that the reported rates of attention and activity problems, oppositional behavior, and conduct problems in daytime wetting children were around twice the rates reported in children with no daytime wetting. CONCLUSIONS: The increased vulnerability to psychological problems in children as young as 7 years of age with daytime wetting highlights the importance of parents seeking early intervention for the condition to help prevent later psychological problems. Although treatment in a pediatric setting is often successful, clinicians should be aware of the increased risk of disorders, such as attention-deficit/hyperactivity disorder, in children with daytime wetting, because this is likely to interfere with treatment.

Child↗
PubMed2005

Prenatal anxiety predicts individual differences in cortisol in pre-adolescent children.

BACKGROUND: Animal studies suggest that prenatal stress is associated with long-term disturbance in hypothalamic-pituitary-adrenal (HPA) axis function, but evidence in humans is lacking. This study examined the long-term association between prenatal anxiety and measures of diurnal cortisol at age 10 years. METHODS: Measures of cortisol were collected at awakening, 30 min after awakening, and at 4 pm and 9 pm on 3 consecutive days in a sample of 10-year-olds (n = 74) from the Avon Longitudinal Study of Parents and Children, a prospective longitudinal cohort study of mothers and children on whom measures of anxiety and depression were collected in pregnancy and the postpartum period. Analyses examined the links between symptoms of prenatal anxiety and multiple indicators of cortisol, an index of HPA axis functioning. RESULTS: Prenatal anxiety was significantly associated with individual differences in awakening and afternoon cortisol after accounting for obstetric and sociodemographic risk (partial correlations were .32 and .25, p < .05). The effect for awakening cortisol remained significant after controlling for multiple postnatal assessments of maternal anxiety and depression. CONCLUSIONS: This study provides the first human evidence that prenatal anxiety might have lasting effects on HPA axis functioning in the child and that prenatal anxiety might constitute a mechanism for an increased vulnerability to psychopathology in children and adolescents.

Adolescent↗
PubMed2005

The prevalence of symptoms and consultations in pre-school children in the Avon Longitudinal Study of Parents and Children (ALSPAC): a prospective cohort study.

BACKGROUND: Pre-school children are frequent users of health services, but little contemporary data are available describing their symptoms or why they consult. OBJECTIVE: To describe symptom and consultation prevalence in pre-school children and to identify the socio-demographic factor or factors associated with consultations for those symptoms. METHODS: Prospective cohort study of 13,617 pre-school children living in south-west England. Parents completed questionnaires asking about symptoms and consultations for those symptoms at six, 18, 30, 42 and 57 months. RESULTS: During the pre-school years, all children experienced one or more symptoms, most commonly cold, cough, high temperature, vomiting or diarrhoea. Ninety seven percent consulted a doctor at least once, most commonly for cough, high fever and/or earache. Lower parity was most strongly and consistently associated with higher consultation rates. CONCLUSIONS: Fever, respiratory and gastro-intestinal symptoms are a normal part of pre-school life. Research of acute conditions in young children could focus on the most common symptoms leading to consultation, namely cough, fever and earache. Efforts to support parents' help seeking decision making might usefully be targeted at first time parents.

Child, Preschool↗
PubMed2005

Domestic violence risk during and after pregnancy: findings from a British longitudinal study.

OBJECTIVE: The objectives of this study were to examine the rates of domestic violence reported during and after pregnancy and to assess the importance of family adversity. DESIGN: Prospective longitudinal cohort study. SETTING: Bristol Avon, Southwest England. POPULATION: Seven thousand five hundred and ninety-one pregnant women with due dates between 1.4.91 and 31.12.92. METHODS: Questionnaires administered at 18 weeks of gestation and 8 weeks, 8 months, 21 months and 33 months postpartum. MAIN OUTCOME MEASURES: The experience of emotional or physical cruelty by an intimate partner at each time point. RESULTS: Fewer women reported domestic violence victimization during pregnancy than they did postpartum (18 weeks of gestation: 1% physical cruelty, 4.8% emotional cruelty, 5.1% any victimization; 33 months postpartum: 2.9% physical, 10.8% emotional, 11% any victimization). Women who reported being victimized during pregnancy also reported significantly higher levels of social adversity during pregnancy. The number of social adversities reported during pregnancy also predicted postpartum victimization. Women who reported only one adversity during pregnancy were 2.73 (95% CI, 2.16-3.45) times more likely to report physical victimization at 33 months postpartum. Women who reported 5 adversities during pregnancy were 14.69 (95% CI, 7.35-29.37) times more likely to report such victimization at 33 months postpartum. For emotional cruelty, women who reported only one adversity during pregnancy were 2.10 (95% CI 1.80-2.46) times more likely to report emotional victimization at 33 months postpartum and 6.10 (95% CI 3.51-10.59) times more likely to report such victimization when five or more adversities were present during pregnancy. CONCLUSIONS: Levels of social adversity reported in pregnancy are important predictors of concurrent and future victimization. Screening for social adversity factors could help identify women at high risk for future domestic violence.

Adolescent↗
PubMed2005

Negative self-schemas and the onset of depression in women: longitudinal study.

BACKGROUND: Beck's cognitive theory of depression has received little empirical support. AIMS: To test whether those with negative self-schemas were at risk of onset of depression. METHOD: Data were collected by postal questionnaire from 12,003 women recruited during early pregnancy; questionnaires included measures of depressive symptoms and negative self-schemas. Regular questionnaires were sent during pregnancy and following childbirth. RESULTS: Of 8540 women not depressed when recruited, 8.6% (95% CI 8.0-9.2) became depressed 14 weeks later. Those in the highest tertile for negative self-schema score were more likely to become depressed than those in the lowest tertile (odds ratio 3.04, 95% CI 2.48-3.73). The association remained after adjustment for baseline depressive symptoms and previous depression (OR 1.6, 95% CI 1.27-2.02) and was of similar magnitude for onset 3 years later. CONCLUSIONS: Holding a negative self-schema is an independent risk factor for the onset of depression in women. This finding supports a key element of Beck's cognitive theory. Understanding more about how negative self-schemas arise should help inform preventive policies.

Adolescent↗
PubMed2004

Thimerosal exposure in infants and developmental disorders: a prospective cohort study in the United kingdom does not support a causal association.

OBJECTIVE: There is an established link between exposure to mercury and impaired childhood cognitive development and early motor skills. Thimerosal (also known as thiomersal), a preservative used in a number of children's vaccines, contains ethylmercury (an organic compound of mercury), and there has been concern that this exposure to mercury may be of some detriment to young children. The aim of this research was to test in a large United Kingdom population-based cohort whether there is any evidence to justify such concerns. METHODS: We used population data from a longitudinal study on childhood health and development. The study has been monitoring >14,000 children who are from the geographic area formerly known as Avon, United Kingdom, and were delivered in 1991-1992. The age at which doses of thimerosal-containing vaccines were administered was recorded, and measures of mercury exposure by 3, 4, and 6 months of age were calculated and compared with a number of measures of childhood cognitive and behavioral development covering the period from 6 to 91 months of age. RESULTS: Contrary to expectation, it was common for the unadjusted results to suggest a beneficial effect of thimerosal exposure. For example, exposure at 3 months was inversely associated with hyperactivity and conduct problems at 47 months; motor development at 6 months and at 30 months; difficulties with sounds at 81 months; and speech therapy, special needs, and "statementing" at 91 months. After adjustment for birth weight, gestation, gender, maternal education, parity, housing tenure, maternal smoking, breastfeeding, and ethnic origins, we found 1 result of 69 to be in the direction hypothesized-poor prosocial behavior at 47 months was associated with exposure by 3 months of age (odds ratio: 1.12; 95% confidence interval: 1.01-1.23) compared with 8 results that still supported a beneficial effect. CONCLUSIONS: We could find no convincing evidence that early exposure to thimerosal had any deleterious effect on neurologic or psychological outcome.

Animals↗
PubMed2003

Child maltreatment in the "children of the nineties:" the role of the child.

AIM: To determine characteristics of children that may predispose to maltreatment. METHODS: The research is based on a large cohort study, the Avon Longitudinal Study of Parents and Children. Out of 14,256 children participating in the study, 115 have been identified as having been placed on local child protection registers prior to their 6th birthday. Data on the children have been obtained from obstetric data and from a series of parental questionnaires administered during pregnancy and the first 3 years of life. Risk factors have been analysed using logistic regression analysis. RESULTS: Significant relationships were found between low birthweight (OR 2.08), unintended pregnancies (OR 2.92), poor health (OR 1.91) and developmental problems (OR 1.99) in infancy, and subsequent maltreatment. In addition, mothers of registered children were less likely to have reported positive attributes in their 4-week-old infant. In contrast, negative attributes in infancy, feeding and crying problems, and frequent temper tantrums were not significantly associated with maltreatment. CONCLUSIONS: While child factors are significant, they are only a small part of the overall complex set of circumstances and conditions that ultimately lead to abuse or neglect. Parental attitudes towards the child may be more significant than the actual characteristics of the child.

Child↗
PubMed2002

Child maltreatment in the "Children of the Nineties:" deprivation, class, and social networks in a UK sample.

AIM: To determine risk factors for child maltreatment within the socio-economic environment of a contemporary UK child population. METHODS: The research is based on a large cohort study, the Avon Longitudinal Study of Parents and Children. Out of 14256 children participating in the study, 115 have been identified as having been placed on local child protection registers prior to their 6th birthday. Data on the socio-economic environment of the families have been obtained from a series of questionnaires administered during pregnancy and the first 3 years of life. Risk factors have been analyzed using logistic regression analysis. RESULTS: Four indicators of deprivation all showed significant relationships with registration. Adjusted odds ratios were 2.33 for paternal unemployment; 7.65 for council housing; 2.16 for overcrowding; and 2.33 for car ownership. There was a strong relationship between the number of indicators of deprivation and the risk of maltreatment. In a second model, maternal unemployment, high mobility (> 3 house moves in the previous 5 years) and a poor social network were also significant with odds ratios of 2.82, 2.81, and 3.09, respectively. CONCLUSIONS: This study confirms the importance of social factors in the etiology of child maltreatment. Social deprivation is an important determinant of child maltreatment, and encompasses a number of different aspects, including financial security, housing situation and material benefits; in addition, the job situation of the parents and the stability and richness of their social networks all have a significant impact on risk of maltreatment. Interventions at both an individual and a community level are important to support families and reduce the risk of maltreatment.

Adult↗