Time trends in family risks and their impact Stephan Collishaw & Barbara Maughan MRC SGDP Centre Institute of Psychiatry Kings College London

Time trends in family risks Recent decades Marked changes in family demographicsMarked changes in family demographics –age at marriage / cohabitation –age at birth of first child –family size –partnership stability / breakdown –complexity of family forms Increases in psychosocial disorders among young peopleIncreases in psychosocial disorders among young people

Time trends in adolescent conduct problems Collishaw et al, 2004

Questions do changing family patterns explain trends in child outcomes?do changing family patterns explain trends in child outcomes? do the same risk factors contribute todo the same risk factors contribute to –individual differences in behaviour problems? –overall levels of behaviour problems? does the impact of family risks change when their prevalence changes?does the impact of family risks change when their prevalence changes?

ONS Population Trends 102, 2000 & Social Trends 20, 1990 Divorce rate per 1,000 married population (England & Wales)

Hypothesis increasing prevalence of divorce associated with reduction in impactincreasing prevalence of divorce associated with reduction in impact –pre-divorce selection effects less troubled familiesless troubled families less parental discordless parental discord –post-divorce consequences less social stigmaless social stigma increased awareness of impact for childrenincreased awareness of impact for children

Parental divorce and child outcomes meta analysis (Amato, 2001) Decade of publication

Parental divorce and child outcomes meta analysis (Amato, 2001) Decade of publication

UK Cohorts Ely et al, 1999; Sigle-Rushton et al, 2005 Cohort

Possible explanations change in nature of marital dissolutionchange in nature of marital dissolution –low discord divorce especially distressing for children increasing gap in economic well-beingincreasing gap in economic well-being –single-parent families not benefited from economic expansion

Aims update picture to include more recent cohortupdate picture to include more recent cohort examine 3 family indicatorsexamine 3 family indicators –family type –family income –family size explore changes in prevalence and impactexplore changes in prevalence and impact illustrate changes in correlatesillustrate changes in correlates test how far changing family risks account for rising levels of conduct problemstest how far changing family risks account for rising levels of conduct problems

Samples Age 16

Family-based correlates – Family type (single vs. step vs. intact) – Family income (<60% median vs. remainder) – Family size (4+ children vs. 1-3 children) Adolescent conduct problems – fighting – bullying – stealing – lying – disobedience Measures

ONS Population Trends 102, 2000 & Social Trends 20, 1990 Cohort 1 Cohort 2 Cohort 3 Divorce rate per 1,000 married population (England & Wales)

Teenagers living with both birth parents

Teenagers living in a step-family

Teenagers living in single-parent households

Low income by cohort: intact families

Proportion of families in poverty: Single parent vs. intact families Single Intact

Increasing income-inequality: single parent vs. intact families OR = 8.5 Single Intact

Increasing income-inequality: single parent vs. intact families OR = 8.5OR = 10.1 Single Intact

Increasing income-inequality: single parent vs. intact families OR = 8.5OR = 10.1OR = 19.4 Single Intact

Family type and conduct problems by cohort Family type OR = 1.9

Family type and conduct problems by cohort Family type OR = 1.9 OR = 2.1

Family type and conduct problems by cohort Family type OR = 1.9 OR = 2.1 OR = 1.8

Family type and conduct problems by cohort Family type OR = 2.7

Family type and conduct problems by cohort Family type OR = 2.7 OR = 2.2

Family type and conduct problems by cohort Family type OR = 2.7 OR = 2.2 OR = 1.6

Summary: family type Risk factorExposureImpact Single parent familyUpNo change Step family UpDown?

Social Trends, 2002 Absolute household disposable income in the UK ( )

Social Trends, 2006 Relative poverty in the UK ( )

Relative poverty by study cohort

Relative poverty and conduct problems by cohort Low income OR = 1.4

Relative poverty and conduct problems by cohort Low income OR = 1.4 OR = 2.1

Relative poverty and conduct problems by cohort Low income OR = 1.4 OR = 2.1 OR = 1.7

Family size by cohort: % four or more children

Family size and conduct problems by cohort N children OR = 3.0

Family size and conduct problems by cohort N children OR = 3.0 OR = 2.3

Family size and conduct problems by cohort N children OR = 3.0 OR = 2.3 OR = 1.8

Summary of findings up to now Risk factorExposureImpact Single parent familyUpNo change Step family UpDown? Relative povertyNo changeUp Large family sizeDownDown

Conduct problems: high scores Total OR = 1.56 per cohort

What contributes to time trends in conduct problems?

What contributes to time trends in conduct problems?

What contributes to time trends in conduct problems?

What contributes to time trends in conduct problems?

Some conclusions 1. Parallel trends in risks and outcomes do not imply a causal link –Increase in divorce rate over the past 30 years –Increase in conduct problems over the same time period –However, trends in family type appear largely independent of trends in conduct problems

Some conclusions 2. Correlates of risk factors may change over time –E.g. Amato –Only had limited data with which to look at this –Socio-economic disadvantage even more strongly associated with single parenthood in more recent cohorts

Some conclusions 3. Implication: changes in impact of a risk factor as important as changes in exposure –Focus on changes in exposure insufficient –Also need to consider possible change in association between risk and outcome –E.g. 1: family type and conduct problems; impact the same or reduced over time –E.g. 2: relative poverty and conduct problems; impact gone up over time

Some conclusions. 4. Different explanatory models needed for understanding individual differences and level differences –Family type, income and size all associated with CP at individual level –But, trends in these aspects of family life only made modest contribution to understanding of level differences –Different factors may be relevant for the two

Time trends in family risks and their impact Stephan Collishaw & Barbara Maughan MRC SGDP Centre Institute of Psychiatry Kings College London

Prevalence and odds of low income by family type and cohort OR =