Short-term impacts of Universal Basic Income on population mental health inequalities in the UK: A microsimulation modelling study.

BACKGROUND: Population mental health in the United Kingdom (UK) has deteriorated, alongside worsening socioeconomic conditions, over the last decade. Policies such as Universal Basic Income (UBI) have been suggested as an alternative economic approach to improve population mental health and reduce health inequalities. UBI may improve mental health (MH), but to our knowledge, no studies have trialled or modelled UBI in whole populations. We aimed to estimate the short-term effects of introducing UBI on mental health in the UK working-age population. METHODS AND FINDINGS: Adults aged 25 to 64 years were simulated across a 4-year period from 2022 to 2026 with the SimPaths microsimulation model, which models the effects of UK tax/benefit policies on mental health via income, poverty, and employment transitions. Data from the nationally representative UK Household Longitudinal Study were used to generate the simulated population (n = 25,000) and causal effect estimates. Three counterfactual UBI scenarios were modelled from 2023: "Partial" (value equivalent to existing benefits), "Full" (equivalent to the UK Minimum Income Standard), and "Full+" (retaining means-tested benefits for disability, housing, and childcare). Likely common mental disorder (CMD) was measured using the General Health Questionnaire (GHQ-12, score ≥4). Relative and slope indices of inequality were calculated, and outcomes stratified by gender, age, education, and household structure. Simulations were run 1,000 times to generate 95% uncertainty intervals (UIs). Sensitivity analyses relaxed SimPaths assumptions about reduced employment resulting from Full/Full+ UBI. Partial UBI had little impact on poverty, employment, or mental health. Full UBI scenarios practically eradicated poverty but decreased employment (for Full+ from 78.9% [95% UI 77.9, 79.9] to 74.1% [95% UI 72.6, 75.4]). Full+ UBI increased absolute CMD prevalence by 0.38% (percentage points; 95% UI 0.13, 0.69) in 2023, equivalent to 157,951 additional CMD cases (95% UI 54,036, 286,805); effects were largest for men (0.63% [95% UI 0.31, 1.01]) and those with children (0.64% [95% UI 0.18, 1.14]). In our sensitivity analysis assuming minimal UBI-related employment impacts, CMD prevalence instead fell by 0.27% (95% UI -0.49, -0.05), a reduction of 112,228 cases (95% UI 20,783, 203,673); effects were largest for women (-0.32% [95% UI -0.65, 0.00]), those without children (-0.40% [95% UI -0.68, -0.15]), and those with least education (-0.42% [95% UI -0.97, 0.15]). There was no effect on educational mental health inequalities in any scenario, and effects waned by 2026. The main limitations of our methods are the model's short time horizon and focus on pathways from UBI to mental health solely via income, poverty, and employment, as well as the inability to integrate macroeconomic consequences of UBI; future iterations of the model will address these limitations. CONCLUSIONS: UBI has potential to improve short-term population mental health by reducing poverty, particularly for women, but impacts are highly dependent on whether individuals choose to remain in employment following its introduction. Future research modelling additional causal pathways between UBI and mental health would be beneficial.

Causal Assessment of Income Inequality on Self-Rated Health and All-Cause Mortality: A Systematic Review and Meta-Analysis.

Policy Points Income is thought to impact a broad range of health outcomes. However, whether income inequality (how unequal the distribution of income is in a population) has an additional impact on health is extensively debated. Studies that use multilevel data, which have recently increased in popularity, are necessary to separate the contextual effects of income inequality on health from the effects of individual income on health. Our systematic review found only small associations between income inequality and poor self-rated health and all-cause mortality. The available evidence does not suggest causality, although it remains methodologically flawed and limited, with very few studies using natural experimental approaches or examining income inequality at the national level. CONTEXT: Whether income inequality has a direct effect on health or is only associated because of the effect of individual income has long been debated. We aimed to understand the association between income inequality and self-rated health (SRH) and all-cause mortality (mortality) and assess if these relationships are likely to be causal. METHODS: We searched Medline, ISI Web of Science, Embase, and EconLit (PROSPERO: CRD42021252791) for studies considering income inequality and SRH or mortality using multilevel data and adjusting for individual-level socioeconomic position. We calculated pooled odds ratios (ORs) for poor SRH and relative risk ratios (RRs) for mortality from random-effects meta-analyses. We critically appraised included studies using the Risk of Bias in Nonrandomized Studies - of Interventions tool. We assessed certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation framework and causality using Bradford Hill (BH) viewpoints. FINDINGS: The primary meta-analyses included 2,916,576 participants in 38 cross-sectional studies assessing SRH and 10,727,470 participants in 14 cohort studies of mortality. Per 0.05-unit increase in the Gini coefficient, a measure of income inequality, the ORs and RRs (95% confidence intervals) for SRH and mortality were 1.06 (1.03-1.08) and 1.02 (1.00-1.04), respectively. A total of 63.2% of SRH and 50.0% of mortality studies were at serious risk of bias (RoB), resulting in very low and low certainty ratings, respectively. For SRH and mortality, we did not identify relevant evidence to assess the specificity or, for SRH only, the experiment BH viewpoints; evidence for strength of association and dose-response gradient was inconclusive because of the high RoB; we found evidence in support of temporality and plausibility. CONCLUSIONS: Increased income inequality is only marginally associated with SRH and mortality, but the current evidence base is too methodologically limited to support a causal relationship. To address the gaps we identified, future research should focus on income inequality measured at the national level and addressing confounding with natural experiment approaches.

The Relationship Between Time Spent on Social Media and Adolescent Cigarette, E-cigarette, and Dual Use: A Longitudinal Analysis of the UK Millennium Cohort Study.

INTRODUCTION: To estimate the effect of social media use in 14 year olds on risk of and inequalities in cigarette, e-cigarette, and dual use at 17 years, using the UK-representative Millennium Cohort Study (born 2000-2002). AIMS AND METHODS: The relationship of time spent on social media (using questionnaires [n = 8987] and time-use-diaries [n = 2520]) with cigarette, e-cigarette, and dual use was estimated using adjusted odds ratios (AORs) or relative risk ratios (ARRRs). Effect modification was examined (using parental education as an indicator for socioeconomic circumstances) by comparing adjusted risk differences within low and high-parental education groups. Analyses accounted for prespecified confounders (identified via directed acyclic graphs), baseline outcome measures (to address reverse causality), sample design, attrition, and item-missingness (through multiple imputation). RESULTS: Time spent on social media was associated with increased risk of cigarette, e-cigarette, and dual use in a dose-response manner. Social media use for ≥2 hours/day (vs. 1-<30 minutes) was associated with increased cigarette (AOR 2.76 [95% confidence interval 2.19 to 3.48]), e-cigarette (3.24 [2.59 to 4.05]), and dual use (ARRR 4.11 [2.77 to 6.08]). The risk of cigarette use among 30 minutes-<1 hour/day users (vs. non-users) were smaller in those with high versus low parental education (ARDs 1.4% vs. 12.4%). Similar findings were observed across the higher time categories. Analyses using time-use-diaries, in complete case samples, and with additional adjustment for baseline outcome measures generally revealed similar findings. CONCLUSIONS: After accounting for observed confounders and potential reverse causality, findings suggest social media use increases the risk of cigarette, e-cigarette, and dual use in a dose-response manner. Guidance addressing adolescent online safety should be prioritized. IMPLICATIONS: This study's identification of a dose-response relationship and differential effects across socioeconomic groups, could assist in the development of guidance on time spent on social media. The adverse effects of social media use on adolescent cigarette, e-cigarette, and dual use supports legislation aimed at promoting adolescent online safety. Study findings strengthen calls to prohibit social media marketing of nicotine-related products and importantly highlight the need to increase awareness and understanding of the underlying algorithms which drive adolescent exposure to nicotine-related content on social media to ensure they are functioning in a way that best serves the adolescent population.

Quality of ethnicity data within Scottish health records and implications of misclassification for ethnic inequalities in severe COVID-19: a national linked data study.

BACKGROUND: We compared the quality of ethnicity coding within the Public Health Scotland Ethnicity Look-up (PHS-EL) dataset, and other National Health Service datasets, with the 2011 Scottish Census. METHODS: Measures of quality included the level of missingness and misclassification. We examined the impact of misclassification using Cox proportional hazards to compare the risk of severe coronavirus disease (COVID-19) (hospitalization & death) by ethnic group. RESULTS: Misclassification within PHS-EL was higher for all minority ethnic groups [12.5 to 69.1%] compared with the White Scottish majority [5.1%] and highest in the White Gypsy/Traveller group [69.1%]. Missingness in PHS-EL was highest among the White Other British group [39%] and lowest among the Pakistani group [17%]. PHS-EL data often underestimated severe COVID-19 risk compared with Census data. e.g. in the White Gypsy/Traveller group the Hazard Ratio (HR) was 1.68 [95% Confidence Intervals (CI): 1.03, 2.74] compared with the White Scottish majority using Census ethnicity data and 0.73 [95% CI: 0.10, 5.15] using PHS-EL data; and HR was 2.03 [95% CI: 1.20, 3.44] in the Census for the Bangladeshi group versus 1.45 [95% CI: 0.75, 2.78] in PHS-EL. CONCLUSIONS: Poor quality ethnicity coding in health records can bias estimates, thereby threatening monitoring and understanding ethnic inequalities in health.

Childhood attention-deficit hyperactivity disorder: socioeconomic inequalities in symptoms, impact, diagnosis and medication.

BACKGROUND: Children from disadvantaged backgrounds are at greater risk of attention-deficit hyperactivity disorder (ADHD)-related symptoms, being diagnosed with ADHD, and being prescribed ADHD medications. We aimed to examine how inequalities manifest across the 'patient journey', from perceptions of impacts of ADHD symptoms on daily life, to the propensity to seek and receive a diagnosis and treatment. METHODS: We investigated four 'stages': (1) symptoms, (2) caregiver perception of impact, (3) diagnosis and (4) medication, in two data sets: UK Millennium Cohort Study (MCS, analytic n ~ 9,000), with relevant (parent-reported) information on all four stages (until 14 years); and a population-wide 'administrative cohort', which includes symptoms (child health checks) and prescriptions (dispensing records), born in Scotland, 2010-2012 (analytic n ~ 100,000), until ~6 years. We described inequalities according to maternal occupational status, with percentages and relative indices of inequality (RII). RESULTS: The prevalence of ADHD symptoms and medication receipt was considerably higher in the least compared to the most advantaged children in the administrative cohort (RIIs of 5.9 [5.5-6.4] and 8.1 [4.2-15.6]) and the MCS (3.08 [2.68-3.55], 3.75 [2.21-6.36]). MCS analyses highlighted complexities between these two stages, however, those from least advantaged backgrounds, with ADHD symptoms, were the least likely to perceive impacts on daily life (15.7% vs. average 19.5%) and to progress from diagnosis to medication (44.1% vs. average 72.5%). CONCLUSIONS: Despite large inequalities in ADHD symptoms and medication, parents from the least advantaged backgrounds were less likely to report impacts of ADHD symptoms on daily life, and their children were less likely to have received medication postdiagnosis, highlighting how patient journeys differed according to socioeconomic circumstances.

To what extent does income explain the effect of unemployment on mental health? Mediation analysis in the UK Household Longitudinal Study.

BACKGROUND: Employment and income are important determinants of mental health (MH), but the extent that unemployment effects are mediated by reduced income is unclear. We estimated the total effect (TE) of unemployment on MH and the controlled direct effect (CDE) not acting via income. METHODS: We included adults 25-64 years from nine waves of the UK Household Longitudinal Study (n = 45 497/obs = 202 297). Unemployment was defined as not being in paid employment; common mental disorder (CMD) was defined as General Health Questionnaire-12 score ≥4. We conducted causal mediation analysis using double-robust marginal structural modelling, estimating odds ratios (OR) and absolute differences for effects of unemployment on CMD in the same year, before (TE) and after (CDE) blocking the income pathway. We calculated percentage mediation by income, with bootstrapped standard errors. RESULTS: The TE of unemployment on CMD risk was OR 1.66 (95% CI 1.57-1.76), with 7.09% (6.21-7.97) absolute difference in prevalence; equivalent CDEs were OR 1.55 (1.46-1.66) and 6.08% (5.13-7.03). Income mediated 14.22% (8.04-20.40) of the TE. Percentage mediation was higher for job losses [15.10% (6.81-23.39)] than gains [8.77% (0.36-17.19)]; it was lowest for those 25-40 years [7.99% (-2.57 to 18.51)] and in poverty [2.63% (-2.22 to 7.49)]. CONCLUSIONS: A high proportion of the short-term effect of unemployment on MH is not explained by income, particularly for younger people and those in poverty. Population attributable fractions suggested 16.49% of CMD burden was due to unemployment, with 13.90% directly attributable to job loss rather than resultant income changes. Similar analytical approaches could explore how this differs across contexts, by other factors, and consider longer-term effects.

The relationship between time spent on social media and adolescent alcohol use: a longitudinal analysis of the UK Millennium Cohort Study.

BACKGROUND: To estimate the effect of social media use in 14 year olds on risk of and inequalities in alcohol use and binge drinking at 17 years. METHODS: Using the UK-representative Millennium Cohort Study, the relationship between time spent on social media (assessed using questionnaires [n = 8987] and time-use-diaries [n = 2520]) with frequency of alcohol use in the past month and binge drinking was estimated using adjusted odds ratios (AORs) or adjusted relative risk ratios (ARRRs). Associations within low and high parental education groups were compared to examine effect modification. Analyses accounted for pre-specified confounders, baseline outcome measures (to address reverse causality), sample design, attrition and item-missingness (through multiple imputation). RESULTS: Questionnaire-reported time spent on social media was associated with increased risk of alcohol use and binge drinking in a dose-response manner. Compared to 1-< 30 min/day social media users, 30 min-<1 h/day users were more likely to report alcohol use ≥6 times/month (ARRR 1.62 [95% confidence interval 1.20 to 2.20]) and binge drinking (AOR 1.51 [1.22 to 1.87]), as were 1-<2 h/day users (ARRR 2.61 [1.90 to 3.58]; AOR 2.06 [1.69 to 2.52]) and ≥2 h/day users (ARRR 4.80 [3.65 to 6.32]; AOR 3.07 [2.54 to 3.70]). Social media measured by time-use-diary was associated with higher risks, although not always demonstrating a dose-response relationship. The effect of social media use (vs no-use) on binge drinking was larger in the higher (vs lower) parental education groups. Analyses repeated in complete case samples, and with adjustment for baseline outcome measures revealed consistent findings. CONCLUSIONS: Findings suggest social media use may increase risk of alcohol use and binge drinking. Regulatory action protecting adolescents from harmful alcohol-related social media content is necessary.

Understanding inequalities in mental health by family structure during COVID-19 lockdowns: evidence from the UK Household Longitudinal Study.

PURPOSE: The COVID-19 pandemic increased psychiatric distress and impacts differed by family structure. We aimed to identify mechanisms contributing to these inequalities. METHODS: Survey data were from the UK Household Longitudinal Study. Psychiatric distress (GHQ-12) was measured in April 2020 (first UK lockdown; n = 10,516), and January 2021 (lockdown re-introduced following eased restrictions; n = 6,893). Pre-lockdown family structure comprised partner status and presence of children (< 16 years). Mediating mechanisms included: active employment, financial strain, childcare/home-schooling, caring, and loneliness. Monte Carlo g-computation simulations were used to adjust for confounding and estimate total effects and decompositions into: controlled direct effects (effects if the mediator was absent), and portions eliminated (PE; representing differential exposure and vulnerability to the mediator). RESULTS: In January 2021, after adjustment, we estimated increased risk of distress among couples with children compared to couples with no children (RR: 1.48; 95% CI 1.15-1.82), largely because of childcare/home-schooling (PE RR: 1.32; 95% CI 1.00-1.64). Single respondents without children also had increased risk of distress compared to couples with no children (RR: 1.55; 95% CI 1.27-1.83), and the largest PE was for loneliness (RR: 1.16; 95% CI 1.05-1.27), though financial strain contributed (RR: 1.05; 95% CI 0.99-1.12). Single parents demonstrated the highest levels of distress, but confounder adjustment suggested uncertain effects with wide confidence intervals. Findings were similar in April 2020 and when stratified by sex. CONCLUSION: Access to childcare/schooling, financial security and social connection are important mechanisms that need addressing to avoid widening mental health inequalities during public health crises.

The effect of school summer holidays on inequalities in children and young people's mental health and cognitive ability in the UK using data from the millennium cohort study.

BACKGROUND: Summer learning loss has been the subject of longstanding concern among researchers, the public and policy makers. The aim of the current research was to investigate inequality changes in children's mental health and cognitive ability across the summer holidays. METHODS: We conducted linear and logistic regression analysis of mental health (borderline-abnormal total difficulty and prosocial scores on the strengths and difficulties questionnaire (SDQ)) and verbal cognitive ability (reading, verbal reasoning or vocabulary) at ages 7, 11 and 14, comparing UK Millennium Cohort Study members who were interviewed before and after the school summer holidays. Inequalities were assessed by including interaction terms in the outcome models between a discrete binary variable with values representing time periods and maternal academic qualifications. Coefficients of the interaction terms were interpreted as changes from the pre- to post-holiday period in the extent of inequality in the outcome between participants whose mothers had high or low educational qualifications. Separate models were fitted for each age group and outcome. We used inverse probability weights to allow for differences in the characteristics of cohort members assessed before and after the summer holidays. RESULTS: Mental health (borderline/abnormal SDQ total and prosocial scores) at ages 7 and 14 worsened and verbal cognitive ability scores at age 7 were lower among those surveyed after the summer holidays. Mental health inequalities were larger after the holidays at age 7 ([OR = 1.4; 95%CI (0.6, 3.2) and 14: [OR = 1.5; 95%CI (0.7, 3.2)], but changed little at age 11 (OR = 0.9; 95%CI (0.4, 2.6)]. There were differences in pro-social behaviours among those surveyed before/after the school holidays at age 14 [OR = 1.2; 95%CI (0.5, 3.5)] but not at age 7 or 11. There was little change in inequalities in verbal cognitive ability scores over the school holidays [Age 7: b = 1.3; 95%CI (- 3.3, 6.0); Age 11: b = - 0.7; 95%CI (- 4.3, 2.8); Age 14: b = - 0.3; 95%CI (- 1.0, 0.4)]. CONCLUSION: We found inequalities in mental health and cognitive ability according to maternal education, and some evidence or worsening mental health and mental health inequalities across school summer holidays. We found little evidence of widening inequalities in verbal cognitive ability. Widespread school closures during the COVID-19 restrictions have prompted concerns that prolonged closures may widen health and educational inequalities. Management of school closures should focus on preventing or mitigating inequalities that may arise from differences in the support for mental health and learning provided during closures by schools serving more or less disadvantaged children.

Assessing causality in epidemiology: revisiting Bradford Hill to incorporate developments in causal thinking.

The nine Bradford Hill (BH) viewpoints (sometimes referred to as criteria) are commonly used to assess causality within epidemiology. However, causal thinking has since developed, with three of the most prominent approaches implicitly or explicitly building on the potential outcomes framework: directed acyclic graphs (DAGs), sufficient-component cause models (SCC models, also referred to as 'causal pies') and the grading of recommendations, assessment, development and evaluation (GRADE) methodology. This paper explores how these approaches relate to BH's viewpoints and considers implications for improving causal assessment. We mapped the three approaches above against each BH viewpoint. We found overlap across the approaches and BH viewpoints, underscoring BH viewpoints' enduring importance. Mapping the approaches helped elucidate the theoretical underpinning of each viewpoint and articulate the conditions when the viewpoint would be relevant. Our comparisons identified commonality on four viewpoints: strength of association (including analysis of plausible confounding); temporality; plausibility (encoded by DAGs or SCC models to articulate mediation and interaction, respectively); and experiments (including implications of study design on exchangeability). Consistency may be more usefully operationalised by considering an effect size's transportability to a different population or unexplained inconsistency in effect sizes (statistical heterogeneity). Because specificity rarely occurs, falsification exposures or outcomes (i.e., negative controls) may be more useful. The presence of a dose-response relationship may be less than widely perceived as it can easily arise from confounding. We found limited utility for coherence and analogy. This study highlights a need for greater clarity on BH viewpoints to improve causal assessment.

Can centre-based childcare buffer against the negative effects of family adversity on child socio-emotional wellbeing?

BACKGROUND: Different configurations of family adversity affect children's socio-emotional development differently; however, we lack knowledge of moderators amenable to policy intervention. This study explored whether early childhood centre-based childcare moderated the impact of family adversity configurations on socio-emotional development. METHODS: Data were from the Growing Up in Scotland first birth cohort, born 2004-05. Latent class analysis of 19 early childhood family adversity indicators identified four classes: 'Low Risk' (68%), 'Poor Maternal Health' (16.5%), 'Economic Hardship' (10.0%) and 'Multiple Adversities' (5.5%). Latent growth models of externalizing and internalizing symptom trajectories (age 46-152 months, n = 3561) by family adversity controlled for confounding. Moderation by centre-based childcare use was examined through stratification. RESULTS: Compared to 'Low Risk', high-risk classes had more externalizing and internalizing symptoms and internalizing symptoms increased at a faster rate, with 'Multiple Adversities' faring worst. The effects of 'Economic Hardship' on change in externalizing symptoms over time varied by childcare (P = 0.035): relative to the Low Risk group, symptoms increased (+0.04 points/year) among those not using childcare, and decreased (-0.09 points/year) among those who did. The effect of 'Multiple Adversities' on internalizing symptoms also varied (P = 0.034): +0.12 without centre-based childcare; +0.33 with centre-based childcare (patterns were similar for externalizing symptoms but with wide confidence intervals). No moderation was found by 'Poor Maternal Health'. CONCLUSIONS: Centre-based childcare may alleviate disadvantages in socio-emotional wellbeing for children experiencing mainly economic hardship, but may exacerbate them for those experiencing multiple adversities. A better understanding of how early years' services can support families with complex needs is required.

Can mental health competence reduce the higher risk of smoking initiation among teenagers with parents who smoke?

BACKGROUND: Parental smoking strongly influences adolescent smoking, yet few studies have examined factors that may protect against this. We investigated whether skills-based components of positive mental health ('mental health competence', MHC) modified the association between parental and teenager smoking, in the UK-representative Millennium Cohort Study (approximately 18 000 children, born 2000-02; analytic sample: n = 10 133). METHODS: Cohort members (CMs) reported at 14 years (y) whether they had ever smoked cigarettes. A dichotomized variable indicated whether one/both parents smoked when CMs were 11 y. A four-class latent MHC measure captured learning skills and prosocial behaviours at 11 y: High, High-Moderate, Moderate, Low. We examined effect measure modification (on the additive scale) by comparing risk differences (RDs) for CM smoking according to parental smoking, within each MHC class. We then estimated RDs for CM smoking according to combinations of parental smoking and MHC. Analyses accounted for confounding, sample design, attrition and item missingness. RESULTS: CMs were more likely to smoke cigarettes if their parent(s) smoked (27%) than CMs with no parent(s) who smoked (11%; RD: 16%). When stratified by MHC, RDs were stronger for low MHC (21%; 95% CI 11-31%) than other MHC classes (ranging: 7-11%). Compared to CMs with high MHC and non-smoker parents, those with low MHC and parent(s) who smoked had an RD of 28% (95% CI 20-36%). This was greater than the sum of RDs for those with low MHC and non-smoker parent(s) [7% (2-14%)] plus those with high MHC and whose parent(s) smoked [11% (7-15%)]. There was limited effect measure modification by moderate or High-Moderate MHC. CONCLUSION: Improving MHC to moderate levels may help reduce intergenerational transference of smoking.

Do bedroom screens and the mealtime environment shape different trajectories of child overweight and obesity? Research using the Growing Up in Scotland study.

OBJECTIVE: To investigate how mealtime setting, mealtime interaction and bedroom screens are associated with different trajectories of child overweight and obesity, using a population sample. METHODS: Growth mixture modelling used data from children in the Growing Up in Scotland Study born in 2004/5 (boys n = 2085, girls n = 1991) to identify trajectories of overweight or obesity across four time points, from 46 to 122 months. Using data from children present at all sweeps, and combining sexes (n = 2810), mutually adjusted associations between primary exposures (mealtime setting, mealtime interaction and bedroom screens) and trajectory class were explored in multinomial models; controlling for early life factors, household organisation and routines, and children's diet patterns, overall screen use, physical activity and sleep. RESULTS: Five trajectories were identified in both sexes: Low Risk (68% of sample), Decreasing Overweight (9%), Increasing Overweight (12%), High/Stable Overweight (6%) and High/Increasing Obesity (5%). Compared with the Low Risk trajectory, High/Increasing Obesity and High/Stable Overweight trajectories were characterised by early increases in bedroom screen access (respective relative risk ratios (RRR) and 95% confidence intervals: 2.55 [1.30-5.00]; 1.62 [1.01-2.57]). An informal meal setting (involving mealtime screen use, not eating in a dining area and not sitting at a table) characterised the High/Increasing Obesity and Increasing Overweight trajectories (respective RRRs compared with Low Risk trajectory: 3.67 [1.99-6.77]; 1.75 [1.17-2.62]). Positive mealtime interaction was associated with membership of the Increasing Overweight trajectory (RRR 1.64 [1.13-2.36]). CONCLUSION: Bedroom screen access and informal mealtime environments were associated with higher-risk overweight and obesity trajectories in a representative sample of Scottish children, after adjusting for a wide range of confounders. Findings may challenge the notion that positive mealtime interaction is protective. Promoting mealtimes in a screen-free dining area and removing screens from bedrooms may help combat childhood obesity.

Could Greater Physical Activity Reduce Population Prevalence and Socioeconomic Inequalities in Children's Mental Health Problems? A Policy Simulation.

BACKGROUND: One in four children 5-16 years (y) of age shows signs of mental health problems in the United Kingdom; risk is higher in economically disadvantaged groups. Greater physical activity is associated with lower risk of internalizing problems such as depression and anxiety. We simulated the potential impact of population-wide physical activity interventions on overall prevalence of internalizing problems, and by family income. Interventions were based on the World Health Organization (WHO) children's target of 60 minutes (min) of moderate-to-vigorous physical activity per day and trial evidence. METHODS: Data were from the UK Millennium Cohort Study, a population-representative cohort of children born in 2000-2002. Household income (5 y) was the exposure; internalizing problems (outcome) were measured using the Strengths and Difficulties Questionnaire (11 y). Of 18,296 singletons, 6,497 had accelerometer physical activity data (mediator, manipulated to simulate interventions) at 7 y. We predicted probabilities of outcome according to exposure in marginal structural models, weighted for attrition and confounding, and adjusted for observed mediator. We then re-estimated probabilities in different physical activity intervention scenarios, assessing income inequalities in internalizing problems with risk ratios (RRs) and differences (RDs) according to income quintile. RESULTS: Simulating universal achievement of the WHO target led to little change in prevalence (10% [95% CI = 8%, 12%]) and socioeconomic inequalities in internalizing problems; RR: 2.2 (1.1, 3.4); RD: 8% [5%,13%]). More modest increases in physical activity achieved weaker results. CONCLUSIONS: Our simulations suggest that large increases in moderate-to-vigorous physical activity in the United Kingdom would have little effect on prevalence and inequalities in child mental health problems.

Weight gain in early years and subsequent body mass index trajectories across birth weight groups: a prospective longitudinal study.

BACKGROUND: Rapid weight gain (RWG) in early-life is associated with increased risk of childhood obesity and is common among low-birth weight infants. Few studies have compared body mass index (BMI) trajectories of children experienced RWG to those who did not, across birth weight groups. We investigated the association between RWG in early-life and subsequent BMI trajectory and whether the association differs by birth weight. METHODS: We included term singletons from the UK Millennium Cohort Study (n = 10 637). RWG was defined as an increase in weight z-scores (derived using UK-WHO growth reference) between birth and 3 years >0.67. Mixed-effect fractional polynomial models were applied to examine the association between RWG and BMI trajectories (5-14 years). Models were further adjusted for confounders and stratified by birth weight-for-gestational-age group. RESULTS: Mean BMI trajectories were higher in children who experienced RWG in early-life, compared with their non-RWG counterparts. RWG was associated with higher BMI at five years [by 0.76 kg/m2 (95% CI: 0.67-0.85) in boys and 0.87 kg/m2 (0.76-0.97) in girls]; the difference persisted into adolescence [1.37 kg/m2 (1.17-1.58) and 1.75 kg/m2 (1.52-1.99) at 14 years, respectively]. Differences remained after adjustment and were particularly greater for children born large-for-gestational-age than those born small- and appropriate-for-gestational-age. Mean BMI trajectories for large-for-gestational-age children with RWG exceeded international reference curves for overweight (for obesity at some ages in girls). CONCLUSIONS: RWG was associated with higher BMI trajectories throughout childhood and adolescence, especially in large-for-gestational-age children. Strategies for obesity prevention need to address factors during and before infancy and preventing excessive weight gain among infants who have already had adequate growth in utero.

Temporal effects of maternal psychological distress on child mental health problems at ages 3, 5, 7 and 11: analysis from the UK Millennium Cohort Study.

BACKGROUND: Psychological distress is common among women of childbearing age, and limited longitudinal research suggests prolonged exposure to maternal distress is linked to child mental health problems. Estimating effects of maternal distress over time is difficult due to potential influences of child mental health problems on maternal distress and time-varying confounding by family circumstances. METHODS: We analysed the UK Millennium Cohort Study, a nationally representative sample with data collected throughout childhood. Adopting a marginal structural modelling framework, we investigated effects of exposure to medium/high levels of maternal psychological distress (Kessler-6 score 8+) on child mental health problems (Strengths and Difficulties Questionnaire borderline/abnormal behaviour cut-off) using maternal and child mental health data at 3, 5, 7 and 11 years, accounting for the influence of child mental health on subsequent maternal distress, and baseline and time-varying confounding. RESULTS: Prior and concurrent exposures to maternal distress were associated with higher levels of child mental health problems at ages 3, 5, 7 and 11 years. For example, elevated risks of child mental health problems at 11 years were associated with exposure to maternal distress from 3 years [risk ratio (RR) 1.27 (95% confidence interval (CI) 1.08-1.49)] to 11 years [RR 2.15 (95% CI 1.89-2.45)]. Prolonged exposure to maternal distress at ages 3, 5, 7 and 11 resulted in an almost fivefold increased risk of child mental health problems. CONCLUSIONS: Prior, concurrent and, particularly, prolonged exposure to maternal distress raises risks for child mental health problems. Greater support for mothers experiencing distress is likely to benefit the mental health of their children.

Associations between mental health competence and indicators of physical health and cognitive development in eleven year olds: findings from the UK Millennium Cohort Study.

BACKGROUND: Positive mental health may support healthy development in childhood, although few studies have investigated this at a population level. We aimed to construct a measure of mental health competence (MHC), a skills-based assessment of positive mental health, using existing survey items in a representative sample of UK children, and to investigate its overlap with mental health difficulties (MHD), socio-demographic patterning, and relationships with physical health and cognitive development. METHODS: We analysed the UK Millennium Cohort Study (MCS) when children were aged 11 years. Maternal (n = 12,082) and teacher (n = 6739) reports of prosocial behaviours (PS) and learning skills (LS) were entered into latent class models to create MHC measures. Using descriptive statistics, we examined relationships between MHC and MHD, and the socio-demographic patterning of MHC. Associations between MHC and physical health and cognitive development were examined with relative risk ratios [RRR] (from multinomial models): BMI status (healthy weight, overweight, obesity); unintentional injuries since age 7 (none, 1, 2+); asthma symptoms (none, 1, 2+); and tertiles of test scores for verbal ability, spatial working memory and risk-taking. Models were adjusted for potential confounding. RESULTS: Four MHC classes were identified [percentages for maternal and teacher reports, respectively]: high MHC (high PS, high LS) [37%; 39%], high-moderate MHC (high PS, moderate LS) [36%; 26%]; moderate MHC (moderate PS, moderate LS) [19%; 19%]; low MHC (moderate PS, low LS) [8%; 16%]. Higher MHC was less common in socially disadvantaged children. While MHC and MHD were associated, there was sufficient separation to indicate that MHC captures more than the absence of MHD. Compared to children with high MHC, those in other MHC classes tended to have poorer physical health and cognitive development, particularly those with low MHC or high-moderate MHC. For example, children with maternal-report Low MHC were more likely to have experienced 2+ unintentional injuries (RRR: 1.5 [1.1-2.1]) and to have lower verbal ability scores (RRR: 2.5 [1.9-3.2]). Patterns of results were similar for maternal- and teacher-report MHC. CONCLUSION: MHC is not simply the inverse of MHD, and high MHC is associated with better physical health and cognitive development. Findings suggest that interventions to improve MHC may support healthy development, although they require replication.

Financial Strain, Parental Smoking, and the Great Recession: An Analysis of the UK Millennium Cohort Study.

INTRODUCTION: During the recent "Great Recession," many families in the United Kingdom experienced increased financial strain (FS). The aim of this study was to determine if increases in FS, occurring over the period of the "Great Recession," were associated with increased risks of persistent and relapsed tobacco use among parents. METHODS: We analyzed the Millennium Cohort Study, a longitudinal study of 18819 children born in the United Kingdom between 2000 and 2002. Surveys at 7 (T1, 2008) and 11 years (T2, 2012) spanned the "Great Recession." Three measures of increased FS were defined; "became income poor" (self-reported household income dropped below the "poverty line" between T1 and T2); "developed difficulty managing" (parental report of being "financially comfortable" at T1 and finding it "difficult to manage" at T2); "felt worse off" (parental report of feeling financially "worse off" at T2, compared to T1). Poisson regression was used to estimate risk ratios (RR), adjusted RRs (aRR), and 95% confidence intervals for three outcomes: "persistent tobacco use," "new reported tobacco use," and "relapsed tobacco use." RESULTS: Parents in households which "became income poor" over the period of the "Great Recession" were significantly more likely to report "persistent tobacco use" (aRR = 2.17 [1.83-2.57]) or "new reported tobacco use" (aRR = 1.72 [1.04-2.83]). Ninety-five percent of "new reported tobacco users" had evidence of prior tobacco use suggesting the majority were "relapsed tobacco users." Similar patterns were seen for those who "developed difficulty managing" and "felt worse off." CONCLUSIONS: Increased tobacco use among financially strained families has the potential to widen inequalities and undermine the public health policies that have had positive impacts on tobacco consumption in the United Kingdom. IMPLICATIONS: While several studies have shown that FS is associated with a higher prevalence of tobacco use, heavier smoking, and relapsed tobacco use, most of this work used cross-sectional data and none has focused on parents. We used longitudinal data from the UK Millennium Cohort Study, between 2008 and 2012, to examine the association between FS and parental smoking. We show that parents who experienced increased FS, over the period of the "Great Recession," were more likely to continue using tobacco or to relapse.