Amanda Sacker

Childhood antecedents of schizophrenia and affective illness: social adjustment at ages 7 and 11.

Abstract Objective: To investigate the social adjustment in childhood of people who as adults have psychiatric disorders. Design - Subjects in a prospectively followed up cohort (the national child development study) who had been admitted as adults to psychiatric hospitals were compared with the rest of the cohort on ratings of social behaviour made by teachers at the ages of 7 and 11 years. Subjects: 40 adult patients with schizophrenic illnesses, 35 with affective psychoses, and 79 with neurotic illness who had been admitted for psychiatric reasons by the age of 28. 1914 randomly selected members of the cohort who had never been admitted for psychiatric treatment. Main outcome measures: Overall scores and scores for overreaction (externalising behaviour) and underreaction (internalising behaviour) with the Bristol social adjustment guide at ages 7 and 11. Results: At the age of 7 children who developed schizophrenia were rated by their teachers as manifesting more social maladjustment than controls (overall score 4.3 (SD 2.4) v 3.1 (2.0); P <0.01). This was more apparent in the boys (5 (2.6)) than the girls underreactive behaviour. At both ages prepsychotic (affective) children differed little from normal controls. By the age of 11 preneurotic children, particularly the girls, had an increased rating of maladjustment (including overreactions and underreactions). Conclusion: Abnormalities of social adjustment are detectable in childhood in some people who develop psychotic illness. Sex and the rate of development of different components of the capacity for social interaction are important determinants of the risk of psychosis and other psychiatric disorders in adulthood.

Breastfeeding and hospitalization for diarrheal and respiratory infection in the United Kingdom Millennium Cohort Study.

OBJECTIVE. The objective of this study was to measure the effect of breastfeeding on hospitalization for diarrheal and lower respiratory tract infections in the first 8 months after birth in contemporary United Kingdom. METHODS. The study was a population-based survey (sweep 1 of the United Kingdom Millennium Cohort Study). Data on infant feeding, infant health, and a range of confounding factors were available for 15890 healthy, singleton, term infants who were born in 2000–2002. The main outcome measures were parental report of hospitalization for diarrhea and lower respiratory tract infection in the first 8 months after birth. RESULTS. Seventy percent of infants were breastfed (ever), 34% received breast milk for at least 4 months, and 1.2% were exclusively breastfed for at least 6 months. By 8 months of age, 12% of infants had been hospitalized (1.1% for diarrhea and 3.2% for lower respiratory tract infection). Data analyzed by month of age, with adjustment for confounders, show that exclusive breastfeeding, compared with not breastfeeding, protects against hospitalization for diarrhea and lower respiratory tract infection. The effect of partial breastfeeding is weaker. Population-attributable fractions suggest that an estimated 53% of diarrhea hospitalizations could have been prevented each month by exclusive breastfeeding and 31% by partial breastfeeding. Similarly, 27% of lower respiratory tract infection hospitalizations could have been prevented each month by exclusive breastfeeding and 25% by partial breastfeeding. The protective effect of breastfeeding for these outcomes wears off soon after breastfeeding cessation. CONCLUSIONS. Breastfeeding, particularly when exclusive and prolonged, protects against severe morbidity in contemporary United Kingdom. A population-level increase in exclusive, prolonged breastfeeding would be of considerable potential benefit for public health.

Lifetime antecedents of cognitive reserve

We used path analysis on data from the British 1946 birth cohort to model lifetime antecedents of cognitive reserve, represented by the NARTat 53 years, and compared this model for verbal memory and psychomotor function at this age, cognitive outcomes that are sensitive to age-associated decline. We showed independent paths from childhood cognition, educational attainment and adult occupation to cognitive reserve, with that from childhood cognition the strongest, and that from adult occupation the weakest. A similar pattern was found for the verbal memory and psychomotor outcomes, although the pathways were weaker than those to the NART. The pattern was also mirrored by the paths from paternal occupation to childhood cognition, educational attainment and adult occupation, with that to childhood cognition the strongest, and that to adult occupation the weakest. The direct influence of paternal occupation on cognitive reserve was negligible, and almost entirely mediated by childhood cognitive ability and educational attainment.

Social inequalities in self reported health in early old age: follow-up of prospective cohort study

Objective To describe differences in trajectories of self reported health in an ageing cohort according to occupational grade. Design Prospective cohort study of office based British civil servants (1985-2004). Participants 10 308 men and women aged 35-55 at baseline, employed in 20 London civil service departments (the Whitehall II study); follow-up was an average of 18 years. Main outcome measures Physical component and mental component scores on SR-36 measured on five occasions. Results Physical health deteriorated more rapidly with age among men and women from the lower occupational grades. The average gap in physical component scores between a high and low grade civil servant at age 56 was 1.60 and this gap increased by 1 over 20 years. The average physical health of a 70 year old man or woman who was in a high grade position was similar to the physical health of a person from a low grade around eight years younger. In mid-life, this gap was only 4.5 years. Although mental health improved with age, the rate of improvement is slower for men and women in the lower grades. Conclusions Social inequalities in self reported health increase in early old age. People from lower occupational grades age faster in terms of a quicker deterioration in physical health compared with people from higher grades. This widening gap suggests that health inequalities will become an increasingly important public health issue, especially as the population ages.

Employment status, employment conditions, and limiting illness: prospective evidence from the British household panel survey 1991–2001

Objectives: To assess the relation of the incidence of, and recovery from, limiting illness to employment status, occupational social class, and income over time in an initially healthy sample of working age men and women. Methods: Cox proportional hazards models. Results: There were large differences in the risk of limiting illness according to occupational social class, with men and women in the least favourable employment conditions nearly four times more likely to become ill than those in the most favourable. Unemployment and economic inactivity also had a powerful effect on illness incidence. Limiting illness was not a permanent state for most participants in the study. Employment status was also related to recovery. Conclusions: Having secure employment in favourable working conditions greatly reduces the risk of healthy people developing limiting illness. Secure employment increases the likelihood of recovery. These findings have considerable implications for both health inequality and economic policies.

The Hospital Anxiety and Depression Scale: A meta confirmatory factor analysis

OBJECTIVE To systematically evaluate the latent structure of the Hospital Anxiety and Depression Scale (HADS) through reanalysis of previous studies and meta confirmatory factor analysis (CFA). METHOD Data from 28 samples were obtained from published studies concerning the latent structure of the HADS. Ten models were considered, including eight previously identified models and two bifactor models. The fit of each model was assessed separately in each sample and by meta CFA. Meta CFA was conducted using all samples and using subgroups consisting of community samples, cardiovascular disease samples and samples from studies administering the English language version of the HADS. RESULTS A bifactor model including all items loading onto a general distress factor and two orthogonal anxiety and depression group factors provided the best fit for the majority of samples. Meta CFA provided further support for the bifactor model with two group factors. This was the case using all samples, as well as all subgroup analyses. The general distress factor explained 73% of the covariance between items, with the (autonomic) anxiety and (anhedonic) depression factors explaining 11% and 16%, respectively. CONCLUSION A bifactor structure provides the most acceptable empirical explanation for the HADS correlation structure. Due to the presence of a strong general factor, the HADS does not provide good separation between symptoms of anxiety and depression. We recommend it is best used as a measure of general distress.

The influence of context, timing, and duration of risk experiences for the passage from childhood to midadulthood

This study investigated the long-term effects of social disadvantage on academic achievement and on subsequent attainments in adulthood. The study drew on data collected for over 30,000 individuals born 12 years apart, following their development from birth to adulthood. The pathways that link social disadvantage to individual development across the life course were analyzed in a developmental-contextual systems model. The results showed that the influence of risk factors associated with socioeconomic disadvantage depended on the developmental stage of the individual, the experience of long-term or continuous disadvantage, and the overall sociohistorical context. Early risk had a moderate influence on the formation of individual competences. The greatest risk was associated with persisting and accumulating experiences of socioeconomic disadvantage throughout childhood and adolescence. Material conditions improved for the later-born cohort, yet pervasive social inequalities existed that affected outcomes during childhood and were consequently reflected in adult attainment.

Health selection in the Whitehall II study, UK

There has been considerable debate over the importance of the health selection hypothesis for explaining social gradients in health. Although studies have argued that it may not be an important explanation of social gradients in health, previous analyses have not estimated, simultaneously, the relative effect of health on changes in social position and of social position on changes in health (social causation). Cross-lagged longitudinal analyses using structural equation models enable the estimation of the relative size of these pathways which would be useful in determining the relative importance of the health selection hypothesis over the social causation hypothesis. Data from four phases of the Whitehall II study (initially consisting of 10,308 men and women aged 35-55 in the British civil service) were collected over a 10 year period. There was no evidence for an effect of mental (GHQ-30 and SF36) or physical health (SF-36) on changes in employment grade. When financial deprivation was used as a measure of social position, there was a significant effect of mental health on changes in social position among men although this health selection effect was over two and a half times smaller than the effect of social position on changes in health. The results suggest that the development of social gradients in health in the Whitehall II study may not be primarily explained in terms of a health selection effect.

Obstetric complications in children born to parents with schizophrenia : a meta-analysis of case-control studies

On the basis of previous findings, we used meta-analyses to consider whether births to parents with schizophrenia have an increased risk of obstetric complications. Meta-analyses were based on published studies satisfying the following selection criteria. The schizophrenic diagnosis could apply to either parent: parents with non-schizophrenic psychoses were not included: only normal controls were accepted. In all, 14 studies provided effect sizes or data from which these could be derived. Studies were identified by data searches through MEDLINE, PSYCLIT and through references of papers relating to the subject. Births to individuals with schizophrenia incur an increased risk of pregnancy and birth complications, low birthweight and poor neonatal condition. However, in each case the effect size is small (mean r = 0.155; 95% CI = 0.057). The risk is greater for mothers with schizophrenia and is not confined to mothers with onset pre-delivery or to the births of the children who become schizophrenic themselves.

Breastfeeding is Associated with Improved Child Cognitive Development: A Population-Based Cohort Study

OBJECTIVE To assess the association between breastfeeding and child cognitive development in term and preterm children. STUDY DESIGN We analyzed data on white singleton children from the United Kingdom Millennium Cohort Study. Children were grouped according to breastfeeding duration. Results were stratified by gestational age at birth: 37 to 42 weeks (term, n = 11,101), and 28 to 36 weeks (preterm, n = 778). British Ability Scales tests were administered at age 5 years (naming vocabulary, pattern construction, and picture similarities subscales). RESULTS The mean scores for all subscales increased with breastfeeding duration. After adjusting for confounders, there was a significant difference in mean score between children who were breastfed and children who were never breastfed: in term children, a two-point increase in score for picture similarities (when breastfed ≥ 4 months) and naming vocabulary (when breastfed ≥ 6 months); in preterm children, a 4-point increase for naming vocabulary (when breastfed ≥ 4 months) and picture similarities (when breastfed ≥ 2 months) and a 6-point increase for pattern construction (when breastfed ≥ 2 months). These differences suggest that breastfed children will be 1 to 6 months ahead of children who were never breastfed. CONCLUSIONS In white, singleton children in the United Kingdom, breastfeeding is associated with improved cognitive development, particularly in children born preterm.