Mothers' mental illness and child behavior problems: Cause-effect association or observation bias

Objective: A number, of studies have consistently found that a mother's mental health (particularly her level of depression) is a strong predictor of mental health problems experienced by her child(ren). However, the validity of this finding is in doubt because the majority of these studies have relied on maternal reports as indicators of children's behavior. Method: This prospective, longitudinal study examines data an the mental health of the mother from prior to the birth of her child to when the child reaches 14 years of age. Child behavior is measured at 14 years of age using reports from mother and child. Mother and child responses are compared to provide an indication of the possible magnitude of maternal observation bias in the reporting of child behavior problems. Results: Anxious and/or depressed mothers tend to report more cases of child behavior problems than do their mentally healthy counterparts or children themselves. Differences between mothers and youths In reporting behavior problems appear to be related to the mothers' mental health. Conclusions: Current maternal mental health impairment appears to have a substantial effect on the reporting of child behavior problems by the mother, thereby raising questions about the validity of reports of child behavior by persons who are currently emotionally distressed.

IBD sharing around the PPARG locus is not increased in dizygotic twins or their mothers

We observe no evidence of linkage to the region around the PPARG locus in several samples of DZ twins who have been genotyped at multiple markers on chromosome 3 (Fig. 1). Among 199 Australian DZ twins ascertained for a history of wheezing2, mean identity by descent (IBD) sharing at the position of PPARG is 0.463 (99% bootstrapped confidence interval=0.412−0.516). We obtained a similar result with 232 pairs of Australian adolescent DZ twins taking part in a longitudinal study of naevus development3 (0.444, 0.390−0.499), and a set of 125 Australian adult DZ twin pairs assessed for anxiety4 (0.508, 0.435−0.580). A Dutch scan of 160 DZ twin pairs5 obtained slightly more encouraging results (0.553, 0.482−0.587, peak maximum lod score (MLS)=0.57). Pooling all these samples gives 0.477 (0.454−0.512) at the position of PPARG. The test for heterogeneity of sharing between studies was not significant (P=0.10). In the combined dataset, the peak IBD sharing (MLS=0.70) is 50 cM closer to the centromere than PPARG. Finally, in a sample of 203 Australian and New Zealand sister pairs where each had given birth to DZ twins6, sharing across the region is also not increased (0.433). We do not replicate linkage in the populations we study to survival of a twin pregnancy or polyovulation.

Exploring the Etiology of the Association Between Birthweight and IQ in an Adolescent Twin Sample

The negative effects of very low birthweight on intellectual development have been well documented, and more recently this effect has been shown to generalise to birthweights within the normal range. In this study we investigate the etiology of this relationship by using a classical twin design to disentangle the contributions of genes and environment. A previous Dutch study (Boomsma et al., 2001) examining these effects indicated that genes were important in mediating the association of birthweight to full IQ measured at ages 7 and 10, but not at ages 5 and 12. Here the association between birthweight and IQ at age 16 is considered (N = 523 twin pairs). Using variance components modeling we found that the genetic variance in birthweight (4%) completely overlapped with that in verbal IQ but not performance or full IQ. Results further showed the importance of shared environmental effects on birthweight (similar to 60%) but not on IQ (with genes explaining up to 72% of IQ variance). Models incorporating a direction of causation parameter between birthweight and IQ provided adequate fit to the data in either causal direction for performance and full IQ, but the model with verbal 10 causing birthweight was preferred to one in which birthweight influenced verbal IQ. As the measurement of birthweight precedes the measurement of twins' IQ at age 16, the influence of verbal IQ might be better considered as a proxy for parents' 10 or education, and it is possible that brighter mothers provide better prenatal environments for their children.

Peak bone mineral accrual and age at menarche in adolescent girls: A 6-year longitudinal study

Background and objectives: The greatest increase in bone mineral content occurs during adolescence. The amount of bone accrued may significantly affect bone mineral status in later life. We carried out a longitudinal investigation of the magnitude and timing of peak bone mineral content velocity (PBMCV) in relation to peak height velocity (PHV) and the age at menarche in a group of adolescent girls over a 6-year period. Methods: The 53 girls in this study are a subset of the 115 girls (initially 8 to 16 years) in a g-year longitudinal study of bone mineral accretion. The ages at PBMCV and PHV were determined by using a cubic spline curve fitting procedure. Determinations were based on height (n = 12) and bone (n = 6) measurements over 6 years. Results: The timing of PBMCV and menarche were coincident, preceded approximately 1 year earlier by PHV. Correlation showed a negative relationship between age at menarche and both peak bone mineral accrual (r = -0.42, P

Adolescent reputation enhancement: Differentiating delinquent, nondelinquent, and at-risk youths

This research reports the findings of two studies conducted to measure and then investigate differences between delinquent, nondelinquent, and at-risk youths' orientations towards reputation enhancement. In the first study, concerning item selection and scale development, the factor structure and content validity of a potential Reputation Enhancement Scale were tested by examining the item responses of the scale completed by 230 high-school students. In the second study, the scale was validated by comparing the item responses of 80 delinquent, 90 at-risk, and 90 nondelinquent adolescents with the responses of the original students. The instrument was found to be reliable (alphas from .64 to .92), indicating that the factors are dependable across different samples, and the coefficients of congruence were sufficiently high to investigate meaningful group differences. Three second-order factors (Conforming Reputation, Nonconforming Reputation, Self-presentation) were derived from the 15 first-order factors. Although multivariate analyses revealed significant differences between the reputational orientations of delinquent, at-risk, and nondelinquent participants, the self-presentation second-order factor did not differentiate the three groups.

Accuracy of predicting a child's response to potential threat: A comparison of children and their mothers

Considerable research has indicated that children and their parents often demonstrate marked discrepancies in their reporting of anxiety-related phenomena. In such cases, the question arises as to whether children are capable of accurately reporting on their anxiety. In the present study, 50 children (aged 5 to 14 years) were asked to approach a large, German Shepherd dog. Prior to the task, both the mother and child independently predicted the closest point likely to be reached by the child and the degree of anxiety likely to be experienced. These predictions were then compared with the actual phenomena displayed by the child during the task. On the behavioural measure (closest step reached), both the child and mother demonstrated equivalent predictive accuracy. On the subjective measure (fear ratings) children were considerably more accurate than their mothers. The data were not influenced by gender, age, or clinical status. The results indicate the ability of children to accurately predict their anxious responses, and support the value of incorporating children's self-reports in the assessment of emotional disorders.

The effects of adolescent cannabis use on educational attainment: a review

This paper reviews research examining the link between cannabis use and educational attainment among youth. Cross-sectional studies have revealed significant associations between cannabis use and a range of measures of educational performance including lower grade point average, less satisfaction with school, negative attitudes to school, increased rates of school absenteeism and poor school performance. However, results of cross-sectional studies cannot be used to determine whether cannabis use causes poor educational performance, poor educational performance is a cause of cannabis use or whether both outcomes are a reflection of common risk factors. Nonetheless, a number of prospective longitudinal studies have indicated that early cannabis use may significantly increase risks of subsequent poor school performance and, in particular, early school leaving. This association has remained after control for a wide range of prospectively assessed covariates. Possible mechanisms underlying an association between early cannabis use and educational attainment include the possibility that cannabis use induces an 'amotivational syndrome' or that cannabis use causes cognitive impairment. However, there appears to be relatively little empirical support for these hypotheses. It is proposed that the link between early cannabis use and educational attainment arises because of the social context within which cannabis is used. In particular, early cannabis use appears to be associated with the adoption of an anti-conventional lifestyle characterized by affiliations with delinquent and substance using peers, and the precocious adoption of adult roles including early school leaving, leaving the parental home and early parenthood.

The efficacy of a universal school-based program to prevent adolescent depression

Evaluated whether a universal school-based program, designed to prevent depression in adolescents, could be effectively implemented within the constraints of the school environment. Participants were 260 Year 9 secondary school students. Students completed measures of depressive symptoms and hopelessness and were then assigned to 1 of 3 groups: (a) Resourceful Adolescent Program Adolescents (RAP A), an 11-session school-based resilience building program, as part of the school curriculum; (b) Resourceful Adolescent Program-Family (RAP-F), the same program as in RAP A, but in which each student's parents were also invited to participate in a 3-session parent program; and (c) Adolescent Watch, a comparison group in which adolescents simply completed the measures. The program was implemented with a high recruitment (88%), low attrition rate (5.8%), and satisfactory adherence to program protocol. Adolescents in either of the RAP programs reported significantly lower levels of depressive symptomatology and hopelessness at post-intervention and 10-month follow-up, compared with those in the comparison group. Adolescents also reported high satisfaction with the program. The study provides evidence for the efficacy of a school-based universal program designed to prevent depression in adolescence.

Gender differences in bone geometry during the adolescent growth spurt

To investigate whether there are gender differences in the bone geometry of the proximal femur during the adolescent years we used an interactive computer program ?Hip Strength Analysis? developed by Beck and associates (Beck et al., Invest Radiol. 1990,25:6-18.) to derive femoral neck geometry parameters from DXA bone scans (Hologic 2000, array mode). We analyzed a longitudinal data-set collected on 70 boys and 68 girls over a seven year period. Distance and velocity curves for height were fitted for each child utilizing a cubic spline procedure and the age of peak height velocity (PHV) was determined. To control for maturational differences between children of the same chronological age and between boys and girls, section modulus (Z) an index of bending strength, cross sectional area of bone (CSA), sub-periosteal width (SPW), and BMD values at the neck and shaft of the proximal femur were determined for points on each individual?s curve at the age of PHV and one and two years on either side of peak. To control for size differences, height and weight were introduced as co-variates in the two-way analyses of variance looking at gender over time measured at the maturational age points (-2, -1, age of PHV, +1, +2). The following figure presents the results of the analyses on two variables, BMD and Z at neck and shaft regions:After the age of peak linear growth (PHV), independent of body size, there was a gender difference in BMD at the shaft but not at the neck. Section modulus at both sites indicated that male bones became significantly stronger after PHV. Underlying these maturational changes, male bones became wider (SPW) after PHV in both the neck and shaft and enclosed more material (CSA) at all maturational age points at both regions. These results call into question the emphasis on using BMD as a measure of skeletal integrity in growing children

Adolescent depressive symptomatology: Improve schools or help students?

Despite the increasing interest in programs designed to improve the social ecology of schools, surprisingly little is known about whether differences between schools influence student mental health. This 3-year prospective, naturalistic study examines the school effect on adolescent depressive symptomatology (measured by the Center for Epidemiological Studies Depression Scale, CES-D) among 2,489 students from 25 Australian high schools. Multilevel modelling techniques (HLM) formed the basis of the statistical analyses, There were statistically significant school effects on students' depressive symptomatology; however, these were much smaller than expected. Nearly all of the variation in CES-D depression scores was found to be at the student level, indicating that the potential mental health gains from reducing risk factors in school social environments may be extremely limited and have little effect on student depressive symptomatology.

Weight loss during prolonged lactation in rural Bangladeshi mothers

To determine the duration of lactation which is associated with weight loss in rural Bangladeshi mothers and also to determine the relationship with consumption patterns of principal food items, a cross-sectional study was carried out among 791 lactating rural Bangladeshi mothers aged 18-40 years. Results were compared with 333 non-pregnant and non-lactating mothers of a similar age group. The duration of lactation was up to 60 months. The mean difference in body-weight and body mass index (BMI) of lactating mothers who breastfed their children up to 24 months was significantly lower compared to non-lactating mothers of the same age group, but no differences were observed for those who breastfed beyond 24 months. The frequency of consumption of principal food items was comparable between the non-lactating and the lactating mothers who breastfed beyond 24 months. Results of multiple linear regression analysis showed that body-weight of mothers was negatively correlated with 1-12 month(s) and 13-24 months of lactation after controlling for height, education, and food consumption (slope -1.04, p < 0.05 and slope -1.23, p < 0.05 respectively). Height and consumption of meat and milk were significantly positively correlated with body-weight (slope 0.53, p < 0.001; slope 1.44, p < 0.001; and slope 0.75, p < 0.05 respectively). The study concluded that Bangladeshi women who breastfed up to 24 months were of lower weight than non-lactating mothers, most likely due to the effect of lactation. These mothers were not taking any additional foods during their lactating period. Based on the findings of the study, it is recommended that mothers consume additional energy-rich foods during the first 24 months of lactation to prevent weight loss.