Professor John Bynner was a pioneer of social research using comparative longitudinal data, with a fine-tuned gift for predicting what many of the key issues were going to be in longitudinal and life course research and related policy spheres. His legacy is one of a truly remarkable researcher and scholar, but also a great colleague and friend to many. John was also the founding father of the Society for Longitudinal and Lifecourse Studies (SLLS) and this journal. Longitudinal and Life Course Studies (LLCS) published an obituary and tribute to John in 2024 (Schoon, 2024). This manuscript relates to a symposium that took place on 26 September 2024, in a special session organised as part of the annual meeting of the SLLS in Essex, UK. Professor Walter Heinz, a long-time friend and colleague of John's, convened the symposium. Professor Heinz won the SLLS John Bynner Distinguished Scholar Award in 2023, with winners invited to present a keynote at the following year's annual meeting. Instead of a keynote, Professor Heinz chose to organise a symposium that would pay tribute to his dear friend, who sadly passed in August 2023. As Professor Heinz could not attend the meeting in person, SLLS president Professor Dario Spini chaired the symposium. Four guest speakers were invited to highlight the key role John played in longitudinal and life course studies. Professors Paul Clarke (on behalf of Professor David Blane who could not attend), Amanda Sacker, Jeylan Mortimer and Dale Dannefer (in collaboration with Professor Ingrid Schoon, who could not attend) served as the speakers. The transcript was collated and edited by Dr Tony Robertson. The transcript, and in turn manuscript, were edited to remove extraneous material and to smooth or clarify text, including linking to slides used by the presenters and including tables. All speakers have seen the full transcript and agree with the final version of the manuscript.

Objectives Disuse theory predicts that cognitive function is vulnerable to transitions that remove factors that support cognitive skills. We sought to investigate whether non-employment over the working life was associated with cognitive function and decline in later life (≥60 years old), and possible gender differences in the association. Study design Longitudinal study. Method We used data from the MRC National Survey of Health and Development (NSHD). Cognitive function was measured by verbal memory and processing speed. Linear regression was used to test associations between non-employment duration and cognitive function at age 60-64, and conditional change models were used to examine associations between non-employment and cognitive decline from age 60-64 to 69. Gender specific models were adjusted for childhood factors and educational attainment, adult occupational features, and adult health and lifestyle indicators. Missing data was accounted for using multiple imputation by chained equations. Results In fully adjusted models >15 years non-employment was associated with lower cognitive function at age 60-64 in men (verbal memory: -0.72, 95%CI -1.18, -0.26; processing speed: -0.61, 95%CI -1.00, -0.28), but not women. Fully adjusted models also indicated that long-term and intermediate lengths of non-employment were associated with faster decline in verbal memory (-0.38, 95%CI -0.75, -0.02) and processing speed (-0.28, 95%CI -0.52, -0.03) in men. There was no association between non-employment and cognitive decline among women. Conclusion Long-term non-employment in men, but not women, is associated with accelerated cognitive ageing.

AbstractBackgroundAccumulating evidence suggests that the neuro‐immune markers of inflammation may be involved in the onset of neurodegenerative disorders (Bostancıklıoğlu, 2019; Park et al., 2020). However, immune mechanisms linking socioeconomic adversities in later life and neurodegenerative disorders have yet to be fully explored. This study has used a large longitudinal study to investigate the mediating effects of neuro‐immune markers in the socioeconomic disparities of neurocognitive disorders in older adults.MethodData of 4815 participants aged 50 and above from the English Longitudinal Study of Ageing (ELSA) across three waves of data collection. Socioeconomic position was assessed in 2008/9 and neuro‐immune markers in 2012/2013. Neurocognitive disorders were ascertained using cognitive variables available in 2018/2019 using a well‐accepted consensus criterion (Richardson et al., 2019). It was categorised into no cognitive impairment, cognitive impairment, no dementia (CIND) and dementia. Mediation analysis was carried out to investigate the mediation effect of c‐reactive protein (CRP), fibrinogen and white blood cell (WBC) count in the association between socioeconomic position and different subtypes of neurocognitive disorders. All models were adjusted for age, sex, marital status and baseline cognitive status.ResultAfter accounting for potential confounders, CRP, fibrinogen, and WBC partly mediated the association of education, occupation, and wealth with cognitive impairment. Results on dementia were all non‐significant.ConclusionAdverse socioeconomic environment were related to early stages of neurocognitive disorders partly via elevated biomarker levels in later life. Neuroinflammation might be one of the immunobiological mechanisms underlying socioeconomic disparities in cognitive impairment. Further research should explore other plausible biological mechanisms to develop interventions to delay the onset of neurodegeneration.

BackgroundChildren who spent time in non-parental care report poor outcomes in many aspects of their later lives on average, but less is known about differences by ethnicity. We examined whether the health, socioeconomic, family, and living arrangements of adults who had been in non-parental care across the first three decades of adult life varied by ethnicity (White, Black, South Asian).MethodsWe used longitudinal data from the Office for National Statistics Longitudinal Study (LS). Participants were aged<18 years and had never been married at baseline of each census year from 1971-2001 (n= 672,648). Separately for each adult follow-up age group (20 to 29; 30 to 39; 40 to 49), multi-level regression models were used to compare socioeconomic, family, and living arrangements by non-parental care and ethnicity interactions.ResultsAdverse adult outcomes following an experience of non-parental care were conditional on the interaction of non-parental care with ethnicity, mainly in the socioeconomic domain. More negative adult outcomes among the ethnic minority groups following non-parental care in childhood were not found consistently: for some outcomes the White group had poorer outcomes; South Asian individuals had better outcomes than Black people who had been in non-parental care but the within-ethnic group differences were smaller for Black than for South Asian children; and findings differed across the lifespan from early to mid-adulthood as work and family lives evolved.ConclusionWe uncovered much complexity, with minority ethnicity moderating the non-parental care to adult outcomes relationship in both positive and negative ways. Previous work that has sampled children from the population with experience of non-parental care provides incomplete evidence from which to base policy decisions.

Background:Individuals who were separated from their biological family and placed into the care of the state during childhood (out-of-home care) are more prone to developing selected physical and mental health problems in adulthood, however, their risk of cardiovascular disease (CVD) is uncertain. Accordingly, we pooled published and unpublished results from cohort studies of childhood care and adult CVD. Methods:We used two approaches to identifying relevant data on childhood care and adult CVD (PROSPERO registration CRD42021254665). First, to locate published studies, we searched PubMed (Medline) until November 2023. Second, with the aim of identifying unpublished studies with the potential to address the present research question, we scrutinised retrieved reviews of the impact of childhood state care on related adult health outcomes. All included studies were required to have prospective measurement of state care in childhood and a follow-up of CVD events in adulthood as the primary outcome (incident coronary heart disease and/or stroke). Collaborating investigators provided study-specific estimates which were aggregated using random-effects meta-analysis. The Newcastle-Ottawa Scale was used to assess individual study quality. Findings:Thirteen studies (2 published, 11 unpublished) met the inclusion criteria, and investigators from nine provided viable results, including updated analyses of the published studies. Studies comprised 611,601 individuals (301,129 women) from the US, UK, Sweden, Finland, and Australia. Relative to the unexposed, individuals with a care placement during childhood had a 50% greater risk of CVD in adulthood (summary rate ratio after basic adjustment [95% confidence interval]: 1.50 [1.22, 1.84]); range of study-specific estimates: 1.28 to 2.06; I2 = 69%, p = 0.001). This association was attenuated but persisted after multivariable adjustment for socioeconomic status in childhood (8 studies; 1.41 [1.15, 1.72]) and adulthood (9 studies, 1.28 [1.10, 1.50]). There was a suggestion of a stronger state care-CVD association in women. Interpretation:Our findings show that individuals with experience of state care in childhood have a moderately raised risk of CVD in adulthood. For timely prevention, clinicians and policy makers should be aware that people with a care history may need additional attention in risk factor management.

Background While individuals who were separated from their biological family and placed into the care of the state during childhood (out-of-home care) are more prone to developing selected adverse health problems in adulthood, their risk of cardiovascular disease is uncertain. Our aim was to explore this association by pooling published and unpublished results from prospective cohort studies. Methods We used two approaches to identifying relevant data on childhood care and adult cardiovascular disease (PROSPERO registration CRD42021254665). First, to locate published studies, we searched PubMed (Medline) until November 2023. Second, with the objective of identifying unpublished studies with the potential to address the present research question, we scrutinised retrieved reviews on childhood out-of-home care and other adult health outcomes. Included studies were required to satisfy three criteria: a cohort study in which the assessment of care was made prospectively pre-adulthood (in the avoidance of recall bias); data on an unexposed comparator group were available (for the computation of relative risk); and a diagnosis of adult cardiovascular disease events (coronary heart disease, stroke, or their combination) had been made (as opposed to risk factors only). Collaborating investigators provided study-specific estimates which were aggregated using random-effects meta-analysis. The Newcastle-Ottawa Scale was used to assess individual study quality. Findings Twelve studies (2 published, 10 unpublished) met the inclusion criteria, and investigators from nine provided viable results, including updated analyses of the published studies. Studies comprised 611,601 individuals (301,129 women) from the US, UK, Sweden, Finland, and Australia. Five of the nine studies were judged to be of higher methodological quality. Relative to the unexposed, individuals with a care placement during childhood had a 51% greater risk of cardiovascular disease in adulthood (summary rate ratio after age- and sex-adjustment [95% confidence interval]: 1.51 [1.22, 1.86]; range of study-specific estimates: 1.07 to 2.06; I2 = 69%, p = 0.001). This association was attenuated but persisted after adjustment for socioeconomic status in childhood (8 studies; 1.41 [1.15, 1.72]) and adulthood (9 studies, 1.29 [1.11, 1.51]). Interpretation Our findings show that individuals with experience of out-of-home care in childhood have a moderately raised risk of cardiovascular disease in adulthood. Funding Medical Research Council; National Institute on Aging; Wellcome Trust.

Research on socioeconomic position (SEP) and mild neurocognitive impairment, considered a transient state between normal cognitive function and dementia is limited. The purpose of this study was to determine the role of SEP in transitioning between different cognitive states and mortality risk. Using nationally representative English data and utilising a multistate model association between SEP and the risk of transitioning from no cognitive impairment (NOCI) to Cognitive impairment no dementia (CIND), dementia and death were investigated. The potential reverse transition from CIND to NOCI was also explored. The probabilities of transitioning between cognitive states and time spent in each state differed significantly between those with lower and higher levels of SEP. Higher wealth was associated with a reverse transition from CIND to NOCI [HR = 1.56, CI (1.42,1.72)]. Socioeconomic advantage might protect against the progression to the early stages of neurocognitive disorders (CIND) and facilitate the potential reversion from mild cognitive impairment to a healthy cognitive state in later life. Lower levels of education affect the risk of mortality after the onset of dementia.

There is limited research on the longer-term impact of fostering on caregivers’ own children. This study investigates whether the existing children in a fostering household differ from young people in non-caregiving households in the timing of their transitions to key adult roles, known to affect later health and life chances. Using data from the ONS Longitudinal Study, we pooled records from census years 1971 to 2001 and linked them to follow-up records from 1981 to 2011. We identified 2656 children living with a foster child and compared their profiles on the “big five” transitions to roles of adulthood — finishing school; leaving home; finding work and becoming financially independent; getting married; and having children — with those of other children without a foster child in the household (N = 209,453). We fitted multiple exposure models that controlled for childhood sociodemographic confounders, with standard errors adjusted for clustering of records in childhood, to estimate the prevalence of the five roles measured in early adulthood. We found that achieving the transition to adulthood for caregivers’ children was indicated based on four roles. The exception was leaving home. There was some evidence that caregivers’ children might cope better with the transition to adulthood if they were older than the foster child or were female. The findings suggest that supporting foster parents with delaying their children’s transition to adulthood could become part of the role of supervising social workers. Discussing with parents and their adolescent children what barriers might be preventing them from staying in school and what is prompting them to want to leave school and go out to work would be a first step, since educational qualifications have become so dominant for more recent generations of young people aspiring to take up other adult roles.

Many countries have implemented policies to extend working lives in response to population ageing, yet there remains little understanding of what drives paid work in later life, nor how this is changing over time. This paper utilises the 1988/89 Survey of Retirement and Retirement Plans, the 1999 British Household Panel Survey and the 2008 English Longitudinal Study of Ageing, to investigate drivers of paid work in the ten years surrounding state pension age (SPA) for women and men in, comparing cohorts born in the 1920s, 1930s and 1940s. Using optimal matching analysis with logistic and multinomial regression models, the study assesses the relative importance of lifecourse histories, socio-economic circumstances and contemporaneous factors, in determining paid work in mid- and later life. Participation in paid work in the five years preceding and beyond SPA increased markedly for men and women across cohorts, with women's lifecourses and engagement with paid work changing considerably in these periods. However, for women, a lifetime history of paid work remained a crucially important predictor of paid work in later life, and this relationship has strengthened over time. Experiencing divorce has also become an important driver of paid work around SPA for the youngest cohort. Having children later, and still having a mortgage, also independently predict labour force participation for women and men. Across all cohorts and for women and men, working at these older ages was a function of higher income and better health. These findings suggest that policies which enable people to maintain ties to paid work across the lifecourse may be more effective at encouraging later-life employment than those concerned only with postponing the retirement transition.

Background Evidence on the neuroinflammatory embedding of adverse socioeconomic conditions is still emerging. Furthermore, most studies have relied on either C-reactive protein or fibrinogen and neglects the time-varying nature of biological responses. Utilising longitudinal data, the current study examined the effects of wealth on long-term trajectories of a more novel biomarker: Insulin-like growth factor (IGF-1) in middle-aged adults. Methods Data from the English Longitudinal Study of Ageing waves 4 (2008/09) through 9 (2018/2019 were used. The analytic sample includes 7,376 participants. IGF-1 data collection took place at baseline wave 4 (2008/9), wave 6 (2012/13) and wave 8/9 (2018/19). Socioeconomic marker, wealth was selected from baseline wave 4. Growth curve models were used to examine IGF-1 levels over time, adjusting for age, sex, marital status, and health status. Results There were significant decrease in IGF-1 levels with age. Being in the highest wealth quintile at baseline was associated with higher IGF levels (β= 0.83 , 95% Confidence interval: 0.44, 1.21) in the adjusted models. IGF-1 level declined rapidly with age from the lowest wealth quintile and appeared to be socioeconomically patterned by wealth (highest wealth quintile: β= -0.073, 95%CI: -0.10, -0.03) Conclusion Our findings indicate biological embedding of social experiences in later life through inflammatipn. IGF-1 can be a mechanistic link to health inequalities. Further studies are needed to explore whether IGF-1 could be a potential intervention target to reduce health risk among socioeconomically disadvantaged groups.

Maternal depression is a major determinant of offspring mental health. Yet, little is understood about how the duration and timing of maternal depression shapes youth risk for depressive symptoms, which if understood could inform when best to intervene. This study aimed to determine how the timing and duration of maternal depression was related to offspring depression in emerging adulthood, and if these associations varied by sex. We analysed data from the Avon Longitudinal Study of Parents and Children (a prenatal cohort in the Avon area of England, 1991–2003), n  = 3,301. We applied the structured lifecourse modelling approach to maternal depression (assessed at 13 points from prenatal period to adolescence) and emerging adult depressive symptoms (age 21). Lifecourse models assessed were accumulation (sum of timepoints when maternal depression was reported), sensitive periods (each period assessed as one during which maternal depression has a stronger effect) and instability (frequent fluctuations in maternal depression). Female adolescents ( n  = 2,132) had higher SMFQ scores (mean = 6.15, SD  = 5.90) than males ( n  = 1,169, mean = 4.87, SD  = 4.82). Maternal depression was most common in the infancy period (21.2% males; 21.4% females). For males, accumulation was the most appropriate lifecourse model; for each additional period of maternal depression, depressive symptoms in emerging adulthood increased by 0.11 (95% CI: 0.07, 0.15, one-sided p value ≤ .001). For females, exposure to maternal depression was associated with increasing depressive symptoms in emerging adulthood, with the largest effect in mid-childhood (increase of 0.27 units, 95% CI 0.03–0.50, p  = .015 for difference between mid-childhood and other time-periods) and a smaller, equal effect at all other time-periods (increase of 0.07 units per time-period, 95% CI: 0.03–0.12, p  = .002). This study highlights the importance of ongoing maternal depression for the development of depression in offspring through to emerging adulthood. Because long-term exposure to maternal depression was particularly important, early interventions are warranted.

Accumulating evidence suggests that the neuro-immune markers of inflammation may be involved in the onset of neurodegenerative disorders (Bostancıklıoğlu, 2019; Park et al., 2020). However, immune mechanisms linking socioeconomic adversities in later life and neurodegenerative disorders have yet to be fully explored. This study has used a large longitudinal study to investigate the mediating effects of neuro-immune markers in the socioeconomic disparities of neurocognitive disorders in older adults. Data of 4815 participants aged 50 and above from the English Longitudinal Study of Ageing (ELSA) across three waves of data collection. Socioeconomic position was assessed in 2008/9 and neuro-immune markers in 2012/2013. Neurocognitive disorders were ascertained using cognitive variables available in 2018/2019 using a well-accepted consensus criterion (Richardson et al., 2019). It was categorised into no cognitive impairment, cognitive impairment, no dementia (CIND) and dementia. Mediation analysis was carried out to investigate the mediation effect of c-reactive protein (CRP), fibrinogen and white blood cell (WBC) count in the association between socioeconomic position and different subtypes of neurocognitive disorders. All models were adjusted for age, sex, marital status and baseline cognitive status. After accounting for potential confounders, CRP, fibrinogen, and WBC partly mediated the association of education, occupation, and wealth with cognitive impairment. Results on dementia were all non-significant. Adverse socioeconomic environment were related to early stages of neurocognitive disorders partly via elevated biomarker levels in later life. Neuroinflammation might be one of the immunobiological mechanisms underlying socioeconomic disparities in cognitive impairment. Further research should explore other plausible biological mechanisms to develop interventions to delay the onset of neurodegeneration.

Objectives:Exposures to adverse events are associated with impaired later-life psychological health. While these associations depend on the type of event, the manner in which associations for different event types depend on when they occur within the life course has received less attention. We investigated associations between counts of adverse events over the life course, and wellbeing and mental health outcomes in older people, according to their timing (age of occurrence), orientation (self or other) and, both their timing and orientation. Design:Linear and logistic random-effects models for repeated observations. Setting:England, 2002-2015. Participants:A total of 4,208 respondents aged >50 years with 22,146 observations across Waves 1-7 of the English Longitudinal Study of Ageing. Measurements:Cumulative adversity was measured by counts of 16 types of events occurring within four age ranges over the life course using retrospective life history data. These were categorized into other- (experienced through harms to others) and self-oriented events. Outcomes included CASP-12 (control, autonomy, self-realization, and pleasure), the eight-item Centre of Epidemiological Studies Depression Scale, and self-appraised subjective life satisfaction. Results:Additional adverse events were associated with lower CASP-12 and life satisfaction scores, and higher odds of probable depressive caseness. In childhood, other-oriented events had a larger negative association with later-life wellbeing than self-oriented events; the converse was found for events occurring in adulthood. Conclusions:Events occurring at all life course stages were independently associated with both later-life wellbeing and depression in a cumulative fashion. Certain age ranges may represent sensitive periods for specific event types.

BackgroundChildren who spent time in non-parental care report poor outcomes in many aspects of their later lives on average, but less is known about differences by type of care. We examined whether socioeconomic, family, and living arrangements of adults who had been in non-parental care across the first three decades of adult life varied by type of care (residential, non-relative and relative).MethodsWe used longitudinal data from the Office for National Statistics Longitudinal Study (LS). Participants were aged<18 years and had never been married at baseline of each census year from 1971-2001 (n=242,843). Separately for each adult follow-up age (20 to 29; 30 to 39; 40 to 49), multi-level logistic regression models were used to compare socioeconomic, family, and living arrangements by different out-of-home care (OHC) experiences.ResultsAny OHC increased the likelihood of poorer functioning in the three domains of socioeconomic circumstances, family formation and relationships, and living arrangements. This was evident in their 20s, 30s and 40s; the most adverse outcomes were observed for those with a history of residential care, followed by non-relative OHC, and the least adverse outcomes for relative OHC. Moderation by childhood census year, age in OHC, and gender altered the relationship between OHC and some, but not all, adult outcomes. The strongest, most consistent, evidence was for widening of inequalities in age 20-29 outcomes across childhood census years and weakest evidence for any moderation of age 40-49 outcomes by age when in OHC.ConclusionEnduring inequalities in social and economic functioning for OHC-experienced adults were found. The evidence overwhelmingly supports the policy to place children in relative care whenever possible, with residential care the least favoured option.

Background: Maternal depression influences offspring mental health. Yet little is understood about how the duration and timing of maternal depression shapes youth risk for depressive symptoms, which if understood could inform when best to intervene. Consequently, this study aimed to determine how the timing and duration of maternal depression was related to offspring depression in late adolescence, and variations by sex.Methods: We used data from the Avon Longitudinal Study of Parents and Children (a prenatal cohort in the Avon area of England, 1991-2003), n=3,301. We applied a structured lifecourse modelling approach to maternal depression (assessed at thirteen points from prenatal period to adolescence) and late adolescent depressive symptoms (age 21). Lifecourse models assessed were accumulation (sum of timepoints when maternal depression was reported), sensitive periods (each period assessed as one during which maternal depression has a stronger effect) and instability (frequent fluctuations in maternal depression).Results: Female adolescents (n=2,132) had higher SMFQ scores (mean=6.15, SD=5.90) than males (n=1,169, mean=4.87, SD=4.82). Maternal depression was most common in the prenatal period (21.1% males; 22.2% females). For males, accumulation was the most appropriate model; for each additional period of maternal depression, depressive symptoms in late adolescence increased by 0.11 (95% CI: 0.07,0.15, 1-sided p value≤0.001). For females, exposure to maternal depression was associated with increasing depressive symptoms in late adolescence, with the largest effect in mid-childhood (increase of 0.27 units, 95% CI 0.03-0.50, p=0.015 for difference between mid-childhood and other time-periods) and a smaller, equal effect at all other time-periods (increase of 0.07 units per time-period, 95% CI: 0.03-0.12, p=0.002).Conclusions: This study highlights the importance of ongoing maternal depression for the development of depression in offspring through to late adolescence. Because long-term exposure to maternal depression was particularly important, early interventions are warranted.

BackgroundAutism can be diagnosed from 2 years of age, although most autistic people receive their diagnosis later than this after they have started education. Research is required to understand why some autistic children are diagnosed late, and the level and nature of unmet need prior to diagnosis for late‐diagnosed children.MethodsWe examined trajectories of emotional, behavioural and social difficulties (EBSDs) across childhood and adolescence, comparing ‘earlier‐diagnosed’ (diagnosed 7 years or younger) with ‘late‐diagnosed’ (diagnosed between 8 and 14 years) autistic children. Data were from the Millennium Cohort Study, a population‐based UK birth cohort. EBSDs were measured using the parent‐report Strengths and Difficulties Questionnaire, at 3, 5, 7, 11 and 14 years. We used Growth Curve Modelling to investigate levels and rates of change in these difficulties, and to compare earlier‐ (n = 146) and late‐diagnosed (n = 284) autistic children.ResultsAged 5, earlier‐diagnosed autistic children had more emotional (i.e., internalising), conduct, hyperactivity and social difficulties; although clinical difficulties in these areas were nevertheless common in late‐diagnosed children. There was a faster annual increase in scores for all domains for late‐diagnosed children, and by age 14 years, they had higher levels of EBSDs. These results persisted when we ran adjusted models, to account for the late‐diagnosed group having higher rates of late‐diagnosed attention deficit/hyperactivity disorder, higher IQ, a higher proportion of females and older and more educated mothers.ConclusionsEmotional, behavioural and social difficulties are associated with, and may influence, the timing of autism diagnosis. Late‐diagnosed autistic children often have high levels of mental health and social difficulties prior to their autism diagnosis, and tend to develop even more severe problems as they enter adolescence.

Autism can be diagnosed from 2 years of age, although most autistic people receive their diagnosis later than this after they have started education. Research is required to understand why some autistic children are diagnosed late, and the level and nature of unmet need prior to diagnosis for late-diagnosed children. We examined trajectories of emotional, behavioural and social difficulties (EBSDs) across childhood and adolescence, comparing ‘earlier-diagnosed’ (diagnosed 7 years or younger) with ‘late-diagnosed’ (diagnosed between 8 and 14 years) autistic children. Data were from the Millennium Cohort Study, a population-based UK birth cohort. EBSDs were measured using the parent-report Strengths and Difficulties Questionnaire, at 3, 5, 7, 11 and 14 years. We used Growth Curve Modelling to investigate levels and rates of change in these difficulties, and to compare earlier- ( n  = 146) and late-diagnosed ( n  = 284) autistic children. Aged 5, earlier-diagnosed autistic children had more emotional (i.e., internalising), conduct, hyperactivity and social difficulties; although clinical difficulties in these areas were nevertheless common in late-diagnosed children. There was a faster annual increase in scores for all domains for late-diagnosed children, and by age 14 years, they had higher levels of EBSDs. These results persisted when we ran adjusted models, to account for the late-diagnosed group having higher rates of late-diagnosed attention deficit/hyperactivity disorder, higher IQ, a higher proportion of females and older and more educated mothers. Emotional, behavioural and social difficulties are associated with, and may influence, the timing of autism diagnosis. Late-diagnosed autistic children often have high levels of mental health and social difficulties prior to their autism diagnosis, and tend to develop even more severe problems as they enter adolescence.

Objectives: In mid-adolescence, to 1) examine cyclical associations between social media use and mental ill health by investigating longitudinal and bidirectional associations, dose response relationships, and changes in social media use and in mental health; 2) assess potential interaction effects between social media use and mental health with pre-existing early life vulnerabilities. Methods: Longitudinal data on 12,114 participants from the Millennium Cohort Study on social media use, depressive symptoms, self-harm and early life risk factors were used. Results: We found little support for the existence of cyclical relationships between social media use and mental health. Where detected, effect sizes were small. Dose response associations were seen in the direction of mental health to social media (depressive symptoms 1 time OR=1.22, 2 times OR=1.71; self-harm 1 time OR=1.17, 2 times OR=1.53), but not for social media to mental health. Changes in social media use and changes in mental health were not associated with each other. We found no evidence to suggest that either social media use or mental health interacted with pre-existing risk for mental ill health. Conclusions: Findings highlight the possibility that observed longitudinal associations between social media use and mental health might reflect other risk processes or vulnerabilities and/or the precision of measures used. More detailed and frequently collected prospective data about online experiences, including those from social media platforms themselves will help to provide a clearer picture of the relationship between social media use and mental health.

The transition to adulthood has become more prolonged, complex, and risk-laden over the past two decades. These changes may contribute to the decline in wellbeing observed among young adults. We test the role of reaching different transition milestones on life satisfaction by ages 25-26 among men and women born 20 years apart in 1970 and 1989-90, using data from the 1970 British Cohort (men n = 3764, women n = 4568) and Next Steps (men n = 3246, women n = 4281) studies. We regressed life satisfaction on education, housing tenure, cohabitation with parents, economic activity, relationship status, and parenthood, and tested the role of changes in the prevalence and association of milestones in explaining cohort differences in life satisfaction using decomposition analyses. Home ownership, full-time employment, cohabitation with a partner, and marriage were robust predictors of life satisfaction in both cohorts. Comparing cohorts, the association of milestones with life satisfaction was stable among men but differed among women: in the later-born cohort, women no longer benefitted from higher education and further suffered from not being in full-time employment. The findings shed new light on the relationships between young adult transitions and life satisfaction during the third decade of life. These support the argument that decreases in wellbeing may be driven by changes in the prevalence and meaning of these milestones over time, particularly among women.

Birth order may foster specific roles for individuals within the family and set in train a dynamic that influences the development of specific behaviors. In this paper, we explored the relationship between birth order, sex, timing of sexual initiation, and its consequences for risky sexual behavior and sexual health. We conducted a path analysis to simultaneously estimate direct and indirect effects using data from the National Survey of Sexual Attitudes and Lifestyles (NATSAL-3). Whereas women born as only-children were more likely to sexually debut at later ages, middle-child boys were significantly more prone to initiate sexual intercourse earlier compared with first-borns. As expected, early sexual initiation was associated with riskier behaviors and sexual health outcomes. These associations were partially moderated by siblings role as confidants about sexuality. Our findings have implications for preventive programs aimed at promoting healthy sexual debuts and behaviors over the life span.