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Background
Tackling mental ill-health is one of the priority areas of the government's
new public health strategy. Between 5% and 20% of the adult population
suffer from depression. Nearly 1 in 5 children also exhibit psychological
problems. While there is a well-established socio-economic gradient
in psychological well-being among adults and children, less is known
about the causal mechanisms underlying this relationship.
An important
line of enquiry has focused on children's experiences of socio-economic
and family disadvantage and the contribution of childhood disadvantage
to the socio-economic gradient in mental health. The mechanisms
are likely to be complex: mental health problems in adulthood could,
for example, be the result of specific childhood psychological,
biological or social factors or a consequence of a generalised vulnerability
acquired through exposure to widespread adversity during childhood.
In assessing
the importance of these mechanisms, account also needs to be taken
of the major social and economic changes which are affecting the
circumstances in which children are growing up and moving into adulthood.
For example, the last decades have seen a rapid increase in childhood
poverty and major changes in employment opportunities.
The study seeks to shed light on the childhood influences on adult
mental health by examining data from two longitudinal surveys which
collected information on children from birth into adulthood.
Aims and
Objectives
The project aims to increase understanding of the inequalities in
mental health through the life course. It will do this by examining:
- whether social
gradients in psychological health in adulthood are mediated through
specific childhood biological, social or psychological disadvantages,
or are the result of a generalised vulnerability acquired from
exposure to widespread adversity during childhood;
- whether the
risk to adult well-being is increased for children who have psycho-social,
educational or health problems resulting from exposure to disadvantage;
- the accumulation
of risk throughout childhood and the importance of the timing
of those risks. The effects of continuous and discontinuous patterns
of disadvantage will be explored and timing effects will also
be considered in terms of the age of the child and the wider social
environment.
Study Design
The study is based on the 1958 National Child Development Study
(NCDS) and the 1970 British Birth Cohort Study (BCS70). The NCDS
takes as its subjects all persons living in Great Britain born between
3 and 9 March 1958. BCS70 collected data about the births of 17,198
babies born in Britain in the week 5 to 11 April. Both cohorts have
been followed up into adulthood and the 12-year gap in their birth
dates makes it possible to examine the influence of broader social
trends on the socio-economic gradient in adult mental health.
Bio-psycho-social risk and protective factors will be derived from
all questionnaire sources. Biological measures include birthweight,
an obstetric risk scale, a pubertal development scale and neurological
soft signs. Psychological factors encompass family relationship
problems, life events and social capital. Social factors include
measures of parents' social position, material disadvantage and
socio-cultural environment. Outcomes during childhood include psychological
and physical health and academic achievement.
Both studies
measure psychological health in adulthood, including the Malaise
Inventory, medically diagnosed conditions, hospitalisations and
psychiatric symptoms. Measures of social position include highest
qualification level, income and occupation-based indices.
A variety of multivariate methods will be used, including structural
equation modelling. This latter methodology allows for competing
hypotheses to be readily tested and is particularly appropriate
for longitudinal data. It allows for the same constructs to be measured
by different observed variables, a feature of relevance to this
study using two birth cohorts.
Policy Implications
The research will contribute to an understanding of the relationship
between material and social disadvantage in childhood and variations
in adult mental health. The work has implications for intervention
at the macro- and micro-levels. At the macro-level, consideration
of period effects will provide evidence for policy change at the
macro-level, if factors such as unemployment and material disadvantage
affecting one generation increase the vulnerability of the next
generation. At the micro-level, a more thorough understanding of
the relationships between social and material disadvantage, psychological
processes within the family and the mental health problems of children
is likely to be a key resource for intervention strategies aimed
at the family unit.
Project Summary
It is well-recognised that socio-economic circumstances in childhood
have an impact on socio-economic position and health in later life.
What is less clear are the mechanisms which underlie this relationship.
The project focused on this complex question, examining the childhood
antecedents of psychological health in adulthood in two British
cohort studies. The National Child Development Study (NCDS) has
been following up a cohort of children born in 1958 and the British
Cohort Study (BCS70) has been following up a cohort of children
born in 1970.
Previous studies
have suggested that social disadvantage affects children's educational
progress and psycho-social development, with educational achievement
and psycho-social adjustment in turn influencing social destinations
and health in adulthood. The project paid particular attention to
the influences on educational and psycho-social resources during
childhood. In response to policy interest in the project, the team
also undertook analyses of inequalities in children's access to
special needs help in primary schools, with findings relating to
the 1970s and 1980s, when the two cohorts were growing up.
Key findings
- A developmental-contextual
model was outlined which examined the stability of social risk
from birth to early adulthood and the maintenance of adequate
resources in the face of that risk. The model gives information
on the accumulating effects of social adversity on the development
of individual resources, by estimating the additional incremental
effects of social risk at subsequent time-points over the lifecourse.
The model also examined inter-generational social mobility and
examined whether social destinations are determined solely by
social origins or whether they are mediated by academic or psycho-social
resources.
- The experience
of social risk at any single time point was a very strong predictor
of risk experienced at a subsequent time point for members of
both cohorts. This was despite the better material circumstances
and upward social mobility observed for parents of the 1970 cohort.
Personal resources were also relatively stable. Approximately
65% of developmental resources could be predicted by resources
at an earlier age. Nevertheless, exposure to socio-economic disadvantage
decreased the level of developmental resources throughout childhood.
Pathways from risk to resources indicated that there were additional
negative impacts added at each measured time point, with the experience
of disadvantage at an early age having the most detrimental effect
in both cohorts.
- A more detailed
examination was undertaken of the routes to adult mental health
inequalities at the crucial transition period from school to work.
Variable-based and person-centred approaches were used as complementary
methods to elicit the mechanisms in greater detail. The variable-based
approach estimates effects of variables on an outcome for the
'average' person. The person-centred approach looked at how variables
combine in individuals. The aetiology of health inequalities is
often discussed in term of three contrasting perspectives: health
selection, social causation and the continuity of both health
and position over time. Analogous to these hypotheses with their
emphasis on negative outcomes, three resilience hypotheses with
an emphasis on positive adaptation were proposed: health protection,
social protection and the stability of resilience.
- The variable-based
approach provided qualified support for all three health inequalities
hypotheses, with the person-centred analyses providing additional
insight into the processes involved. Resilience in adolescence
not only leads to an increased likelihood of escape from social
risk and to a lower overall risk of psychological morbidity in
adulthood, but also protects against poor psychological health
in the context of continued risk. Education was especially effective
at moderating the effects of high social risk.
- In 2000,
members of both cohorts were interviewed using the same questionnaire.
At last, it became possible to examine age, period and cohort
effects on mental well-being and to test whether social inequalities
in adult mental health are increasing or declining over time.
Results indicate that age, period and cohort affect mental health
independently. Mental health improves from early adulthood into
the 30s and then declines again as individuals approach mid-life.
Mental well-being has declined in the years 1981-2000 and the
1970 cohort has poorer mental health than the 1958 cohort. Despite
this general decline in well-being, social inequalities have not
increased over the same period.
- In further
analyses, the influence of home-based and school-based factors
on children's psycho-social adjustment and educational achievement
was examined in more detail. These analyses indicated that the
two sets of factors mediated the relationship with family social
class until late adolescence. By 16, the risk to children from
their family of origin became less important and the social composition
of the school became more important influences on both psycho-social
adjustment and educational achievement.
- The analysis
of access to special needs help found that those with greatest
need, as measured by the surveys' educational and psycho-social
test scores, were most likely to be receiving help. However, given
the same degree of need, children from professional homes were
more likely to be receiving help. Similarly, areas in the south
east of Britain were better funded than average, while areas of
deprivation were not provided with sufficient resources to meet
their children's needs. There thus appeared to be an 'inverse
care law' at work, with resources distributed in inverse proportion
to need.
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