The relationship between mental health and risky decision-making in children and adolescents: a scoping review.

BACKGROUND: Evidence from studies on adult participants and clinical samples of children suggest an association between risky decision-making and mental health problems. However, the extent and nature of this association in the general youth population remains unknown. Therefore, this scoping review explores the current evidence on the relationship between mental health (internalising and externalising symptoms) and risky decision-making in the general youth population. METHODS: A three-step search strategy was followed and applied to four databases. Selection criteria included participants < 18 years representative of the general population, and information on both risky decision-making (assessed using gambling tasks) and internalising /externalising symptoms. Data were extracted and synthesised for study and participant characteristics, aspects and measures for the main variables, and key findings. RESULTS: Following screening, twenty-one studies were retrieved. Non-significant associations were more frequent than significant associations for both internalising and externalising symptoms, particularly for social difficulties and broad externalising symptoms. Among the significant associations, hyperactivity/inattention and conduct problems appeared to be positively associated with risk-taking and negatively associated with quality of decision-making. However, patterns were less clear for links between risky decision-making and internalising symptoms, especially between risk-taking and anxiety symptoms. CONCLUSIONS: The present review suggests predominantly a lack of relationship between risky decision-making and mental health problems, and outlines several possible reasons for it. However, when specificity is considered carefully there seems to be a link between risk-taking and specific externalising problems. Future research should employ study designs aimed at disentangling the direction of this relationship and identifying specific aspects of mental health and risky decision-making that could be eventually addressed by tailored interventions.

Sibling effects on problem and prosocial behavior in childhood: Patterns of intrafamilial "contagion" by birth order.

We investigated longitudinal relations between siblings' problem and prosocial behavior, measured by the Strengths and Difficulties Questionnaire, among different sibship sizes in the UK's Millennium Cohort Study. We identified 3436 families with two children and 1188 families with three children. All children (cohort members and their older sibling [OS]) had valid data on behavior at two time points (in 2004 and 2006). Using structural equation model, we found that for internalizing and externalizing problems, OSs (MOS1 = 6.3 years, MOS2 = 9.1 years at T1) exerted a dominant effect on younger siblings (Mage = 3.12 years at T1; 49.7% boys) across sibship sizes. For prosocial behavior, there was OS dominance in two-child families and youngest sibling dominance in three-child families.

The role of social cognition in mental health trajectories from childhood to adolescence.

We investigated the association between an aspect of Theory of Mind in childhood, false-belief understanding, and trajectories of internalising (emotional and peer) and externalising (conduct and hyperactivity) problems in childhood and adolescence. The sample was 8408 children from the UK's Millennium Cohort Study, followed at ages 5, 7, 11, 14, and 17 years. Social cognitive abilities were measured at 5 and 7 years through a vignette version of the Sally-Anne task administered by an unfamiliar assessor in a socially demanding dyadic interaction. Internalising and externalising problems were measured via the Strengths and Difficulties Questionnaire at 7-17 years. Using latent growth modelling, and after controlling for sex, ethnicity, maternal education, verbal ability, and time-varying family income, we found that superior social cognitive abilities predicted a decrease in emotional problems over time. In sex-stratified analyses, they predicted decreasing conduct problem trajectories in females and lower levels of conduct problems at baseline in males.

Decision-making difficulties mediate the association between poor emotion regulation and eating disorder symptoms in adolescence.

BACKGROUND: The emergence of eating problems during childhood increases the risk for eating disorders (EDs) during young adulthood. Previous studies highlight a relationship between poor self-regulation and onset of eating pathology. In this study, we investigated whether this association is mediated by decision-making difficulties. METHODS: To test this hypothesis, we used data from the Millennium Cohort Study. Decision-making performance was assessed with the Cambridge Gambling Task at age 11. Principal components analysis was used to derive an index of ED symptoms at age 14. The trajectories of scores of two subscales of the Child Social Behaviour Questionnaire, Independence and Self-Regulation (ISR) and Emotional Dysregulation (EmotDy), were modelled from ages 3 to 7 years in a latent growth curve analysis. The individual predicted values of the intercept (set at baseline, 3 years) and the slope (rate of annual change) were then used in the mediation analysis. RESULTS: In our sample of 11 303 individuals, there was evidence for mediation by three measures of decision-making at age 11 (poor quality of decision-making, delay aversion and low risk-adjustment) in the association between EmotDy across ages 3-7 and ED symptoms at age 14 even after the adjustment for relevant covariates. We found no evidence of association between ISR and ED symptoms. CONCLUSION: Our findings suggest that emotion regulation processes during childhood may be relevant for the future onset of ED symptoms via their association with decision-making skills. These findings, obtained from a large, representative, sample, shed light on the relationship between self-regulation, decision-making and symptoms of EDs.

Reciprocal associations between affective decision-making and mental health in adolescence.

Poor affective decision-making has been shown to associate cross-sectionally with poor mental health in clinical populations. However, evidence from general population samples is scarce. Moreover, whether decision-making is prospectively linked to mental health in youth in the general population and whether such associations are reciprocal have yet to be examined. The present study examined bidirectional associations between various aspects of affective decision-making and emotional and behavioural problems at ages 11 and 14 years in 13,366 members of the Millennium Cohort Study. Decision-making (delay aversion, deliberation time, quality of decision-making, risk adjustment, risk-taking) and emotional (emotional symptoms, peer problems) and behavioural (conduct problems, hyperactivity/inattention) problems were measured using the Cambridge Gambling Task and the Strengths and Difficulties Questionnaire, respectively. Results of cross-lagged panel models adjusted for confounding revealed a negative reciprocal association between hyperactivity and quality of decision-making but also positive reciprocal associations between conduct problems and delay aversion, and between peer problems and deliberation time. Emotional problems and peer problems predicted a decrease in risk-taking, conduct problems predicted an increase in risk-taking, and hyperactivity predicted an increase in delay aversion and deliberation time. Furthermore, hyperactivity and conduct problems predicted less risk adjustment, and risk adjustment predicted fewer peer problems. The results suggest that behavioural problems are prospectively linked to greater risk-taking and lower risk adjustment in adolescence. Moreover, adolescents with behavioural problems tend to make poorer decisions and be more delay-averse, but also poorer quality of decision-making and increased delay aversion are associated with more behavioural problems over time.

The Relationship Between Bullying Victimization and Perpetration and Non-suicidal Self-injury: A Systematic Review.

Experience of bullying may be a significant risk factor for non-suicidal self-injury (NSSI). This study had three aims: to systematically investigate the association between bullying and NSSI, analyze the possible mechanisms underlying the two phenomena, and evaluate any differences between bullying victimization and bullying perpetration with respect to NSSI. A systematic search about the association between bullying victimization and perpetration and NSSI was conducted using specific databases (PubMed, Scopus, Science Direct). The following keywords were used in all database searches: "bullying" AND "NSSI" OR "peer victimization" and NSSI. The searches in PubMed, Scopus and Science Direct revealed a total of 88 articles about bullying or peer victimization and NSSI. However, only 29 met our inclusion criteria and were used for the present review. Overall, all studies examined victimization; four studies also evaluated the effects of perpetration and one included bully-victims. According to the main findings, both being a victim of bullying and perpetrating bullying may increase the risk of adverse psychological outcomes in terms of NSSI and suicidality in the short and the long run. To the best of our knowledge, this is the first review to systematically evaluate the relation between bullying victimization/perpetration and NSSI. The main results support a positive association. Future research should evaluate the possible role of specific mediators/moderators of the association between experience of bullying and NSSI.

The relationship between diurnal cortisol slope and cognitive development among children maltreated as infants.

Little is known about the role of hypothalamic-pituitary-adrenal (HPA) axis functioning for children's cognitive development, especially among vulnerable groups. The current study explores the relationship between diurnal cortisol slope and cognitive outcomes among children at the ages of 5 and 6 who have been maltreated as infants and involved with child protective services, using data from the National Survey of Child and Adolescent Well-Being (NSCAW) I (N=158). Multiple regression analyses showed that a greater decline in salivary cortisol from morning to evening was positively associated with scores on applied problems and expressive communication, even after adjustment for confounding. It was also associated with lower odds of cognitive disability. There were null associations with letter-word identification, passage comprehension, auditory comprehension, matrices, and vocabulary. Results suggest that children involved with child protective services as infants, and thus exposed early to likely 'toxic' levels of stressors, may face dysregulation of the HPA axis and particular difficulties in some aspects of cognitive function. Potential explanations and implications for policy are discussed.

Risk-taking to obtain reward: sex differences and associations with emotional and depressive symptoms in a nationally representative cohort of UK adolescents.

BACKGROUND: Cognitive mechanisms that characterize or precede depressive symptoms are poorly understood. We investigated cross-sectional and longitudinal associations between risk taking to obtain reward and adolescent depressive symptoms in a large prospective cohort, using the Cambridge Gambling Task (CGT). We also explored sex differences. METHODS: The Millennium Cohort Study (MCS) is an ongoing UK study, following the lives of 19 000 individuals born 2000/02. The CGT was completed at ages 11 (n = 12 355) and 14 (n = 10 578). Our main exposure was the proportion of points gambled, when the odds of winning were above chance (risk-taking to obtain reward). Outcomes were emotional symptoms (Strengths and Difficulties Questionnaire, SDQ) at age 11 and depressive symptoms (short Mood and Feelings Questionnaire, sMFQ) at age 14. We calculated cross-sectional and longitudinal associations, using linear regressions. RESULTS: In univariable models, there was evidence of cross-sectional associations between risk-taking and SDQ/sMFQ scores, but these associations disappeared after we adjusted for sex. Longitudinally, there was weak evidence of an association between risk-taking and depressive symptoms in females only [a 20-point increase in risk-taking at age 11 was associated with a reduction of 0.31 sMFQ points at age 14 (95% CI -0.60 to -0.02)]. At both time-points, females were less risk-taking than males. CONCLUSIONS: We found no convincing evidence of a relationship between risk-taking to obtain reward and depressive symptoms. There were large sex differences in risk-taking, but these do not appear to contribute to the female preponderance of depressive symptoms in adolescence.

The role of inflammatory markers and cortisol in the association between early social cognition abilities and later internalising or externalising problems: Evidence from a UK birth cohort.

OBJECTIVE: Deficits in social cognition are associated with internalising (emotional and peer problems) and externalising (conduct problems and hyperactivity/inattention) symptoms in youth. It has been suggested that stress may be one of the mechanisms underlying these associations. However, no empirical studies have investigated if physiological stress can explain the prospective associations between social cognition deficits and internalising and externalising symptoms in the general youth population. This study addressed this question and focused on two indicators of physiological stress, dysregulated diurnal cortisol patterns and systemic inflammation. METHOD: Participants were 714 individuals from the Avon Longitudinal Study of Parents and Children (ALSPAC), a UK population-based birth cohort. Bayesian structural equation modelling was used to investigate a) the associations of social cognition abilities at ages 8, 11, and 14 years with internalising and externalising problems at age 17 years and b) the potential mediating effects of cortisol parameters at age 15 years and inflammatory markers [interleukin 6 (IL-6) and C-reactive protein (CRP)] at ages 9 and 16 years. RESULTS: We found that social cognition difficulties were associated with later internalising and externalising problems. Flattened diurnal cortisol slope was associated with hyperactivity/inattention problems two years later. Lower morning cortisol partially mediated the direct association between social communication deficits at 8 years and hyperactivity/inattention and conduct problems at 17 years, even after adjustments for inflammation and confounders (for hyperactivity/inattention: indirect effect = 0.07, 95% CI [0.00, 0.18], p = .042; for conduct problems: indirect effect = 0.04, 95% CI [0.00, 0.11], p = .040). We did not find a significant association between systemic inflammation and social cognition difficulties, internalising problems, or externalising problems. CONCLUSION: Our findings suggest that part of the effect of social communication difficulties in childhood on externalising problems in adolescence was mediated by lower morning cortisol. Hence, our study indicates that the hypoactivity of the hypothalamic-pituitary-adrenal (HPA) axis may be one of the physiological mechanisms linking some social cognition deficits to externalising problems.

Mental health and social difficulties of late-diagnosed autistic children, across childhood and adolescence.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

The role of physical environmental characteristics and intellectual disability in conduct problem trajectories across childhood: A population-based Cohort study.

BACKGROUND: The paucity of research investigating the role of the physical environment in the developmental progression of conduct problems and the potential moderating effects of intellectual disability (ID) is surprising, given the clinical relevance of elucidating environmental determinants of disruptive behaviours. AIMS: To use data from a large UK cohort study to assess associations between physical environmental exposures, ID, and conduct problem trajectories. METHOD: The sample included 8168 Millennium Cohort Study children (1.9% with ID). Multilevel growth curve modelling was used to examine the role of physical environment characteristics in the developmental trajectories of conduct problems after adjustments for ID status. RESULTS: Exposure to external environmental domains was not associated with differences in children's conduct problems across development. Alternatively, internal aspects of the household environment: spatial density (b = 0.40, p < .001) and damp problems (b = 0.14, p < .001) were both significantly associated with increased trajectories. Various individual and familial covariates were positively associated with conduct problems over time, including: presence of ID (b = 0.96, p < .001), autism spectrum disorder (b = 1.18, p < .001), male sex (b = 0.26, p < .001), poverty (b = 0.19, p < .001), maternal depression (b = 0.65, p < .001), and non-nuclear family structure (b = 0.35, p < .001). Positive ID status appeared to moderate the effects of internal household spatial density, reporting a non-linear negative association with spatial density and conduct problems across development (b = -1.08, p < .01). CONCLUSIONS: Our findings highlight the potential harmful consequences of poor internal residential conditions on children's development of disruptive behaviours.

Ability-grouping and problem behavior trajectories in childhood and adolescence: Results from a U.K. population-based sample.

Ability-grouping has been studied extensively in relation to children's academic, but not emotional and behavioral outcomes. The sample comprised 7259 U.K. children (50% male) with data on between-class and within-class ability-grouping at age 7. Peer, emotional, hyperactivity, and conduct problems were measured at ages 7, 11, and 14 years. Children in low within-class ability groups showed more hyperactivity and emotional problems across the study period compared to non-grouped children, after adjustments for the different types of ability grouping and confounding. Additionally, children in the middle within-class ability groups showed more, and those in the top within-class groups less, hyperactivity compared to non-grouped children, after adjustment. Children in lower within-class groups should be monitored closely to ensure that their well-being is not compromised.

Reciprocal relationships between paternal psychological distress and child internalising and externalising difficulties from 3 to 14 years: a cross-lagged analysis.

Research shows that paternal psychological distress is associated with child emotional and behavioural difficulties. However, little is known about the direction of this association including whether it is bidirectional. The aim of this study was to explore the reciprocal relationships between paternal psychological distress and child emotional and behavioural problems longitudinally (at ages 3, 5, 7, 11 and 14 years) in a sample of 13,105 children (49% girls) who participated in the UK's Millennium Cohort Study (MCS), a large-scale, nationally representative, longitudinal survey. Four domains of child problems (emotional symptoms, peer relations, conduct problems and hyperactivity/inattention) were measured with the Strengths and Difficulties Questionnaire and paternal psychological distress was measured with the Kessler K-6 scale. Data were analysed using cross-lagged path models. At all ages, paternal psychological distress predicted both subsequent child emotional symptoms as well as peer problems. Paternal psychological distress at child's age 3 was related to more hyperactivity at age 5 and, at age 5, paternal psychological distress was associated with more conduct problems at age 7. At age 11, paternal distress was also related to age 14 conduct problems and hyperactivity. Child effects were fewer and were found mainly for behavioural problems. Notably, we found bidirectional links between paternal psychological distress and child peer difficulties, from 11 to 14 years. Paternal psychological distress appears to influence child behaviour more consistently than the converse. However, in early adolescence, there appears to be a reciprocal relationship between fathers' mental health problems and children's peer problems.

Do upsetting life events explain the relationship between low socioeconomic status and systemic inflammation in childhood? Results from a longitudinal study.

BACKGROUND: Children from families of low socioeconomic status (SES) are more likely to be exposed to upsetting situations and stressors. Such exposures have, in turn, been linked to inflammation in some studies. In this study we explore if low SES is related to inflammation in children via such stressful life events. METHODS: Data on 4525 children of the Avon Longitudinal Study of Parents and Children, a general population birth cohort, were used to explore associations between SES at ages 0-3 years, upsetting life events at ages 3-9 years and inflammatory markers [interleukin 6 (IL-6) and C-reactive protein (CRP)] at age 9 years. Confounders included body mass index, gender, financial problems, and upsetting life events at ages 0-3 years. RESULTS: Using Structural Equation Modelling, we found that early socioeconomic disadvantage predicted higher levels of IL-6 (ß = 0.034, 95% CI = 0.005, 0.063) even after adjusting for confounders. This association was partially mediated by upsetting life events (ß = 0.003, 95% CI = 0.001, 0.006). CONCLUSIONS: In the general child population, low SES is associated with increased exposure to stressful life events, in turn associated with later inflammation. These findings highlight the role of stressors associated with poverty and disadvantage in the development of inflammation among children in the general population.

Prenatal and childhood adversity and inflammation in children: A population-based longitudinal study.

BACKGROUND: Stressful life events experienced during childhood and early prenatal development have been associated with inflammation during childhood. However, no study has considered these two exposures jointly, or has investigated the effect of their interaction. METHODS: In the Avon Longitudinal Study of Parents and Children, a general-population birth cohort, we explored if inflammatory markers [serum C-reactive protein (CRP) and interleukin 6 (IL-6)] at age 9 years were related to early prenatal events (at 18 weeks pregnancy), childhood events (measured on seven occasions at ages 0-9 years) and their interaction (n = 3,915). Latent growth curve modelling estimated trajectories of childhood events, and linear regression explored associations of prenatal and childhood events with inflammatory markers. Models controlled for ethnicity, socioeconomic status and body mass index, were stratified by gender and considered both unweighted and weighted (by impact) event exposures. RESULTS: Even after adjustment for confounders and prenatal events, both the intercept and the slope of number of childhood events were associated with IL-6, but only in females. The significant effect of the slope held for both weighted (by impact) and unweighted event specifications. Prenatal events were not associated with either inflammatory marker when childhood events were controlled. There was no evidence for synergistic effects of prenatal and childhood events. CONCLUSION: Independently of prenatal adverse life events, the number and increase in number of adverse life events experienced in childhood were associated positively with plasma levels of inflammatory markers, such as IL-6, in girls. This gender specificity warrants further research.

The codevelopment of internalizing symptoms, externalizing symptoms, and cognitive ability across childhood and adolescence.

Cognitive ability, externalizing symptoms, and internalizing symptoms are correlated in children. However, it is not known why they combine in the general child population over time. To address this, we used data on 17,318 children participating in the UK Millennium Cohort Study and followed-up five times between ages 3 and 14 years. We fitted three parallel-process latent growth curve models to identify the parallel unfolding of children's trajectories of internalizing symptoms, externalizing symptoms, and cognitive ability across this period. We also examined the effects of time-invariant (ethnicity, birth weight, maternal education and age at birth, and breastfeeding status) and time-varying covariates (maternal psychological distress and socioeconomic disadvantage) on the growth parameters of the trajectories. The results showed that the intercepts of the trajectories of cognitive ability and, particularly, externalizing symptoms were inversely correlated. Their linear slopes were also inversely correlated, suggesting parallel development. Internalizing symptoms were correlated positively with externalizing symptoms and inversely (and more modestly) with cognitive ability at baseline, but the slope of internalizing symptoms correlated (positively) only with the slope of externalizing symptoms. The covariates predicted 9% to 41% of the variance in the intercepts and slopes of all domains, suggesting they are important common risk factors. Overall, it appears that externalizing symptoms develop in parallel with both cognitive ability and internalizing symptoms from early childhood through to middle adolescence. Children on an increasing trajectory of externalizing symptoms are likely both increasing in internalizing symptoms and decreasing in cognitive skills as well, and are thus an important group to target for intervention.

Stressful life events, inflammation and emotional and behavioural problems in children: A population-based study.

OBJECTIVE: To test the hypothesis that higher plasma levels of inflammatory markers due to exposure to adverse life events may lead to internalising and externalising symptoms in children. METHOD: Using data from the Avon Longitudinal Study of Parents and Children, a general population birth cohort, we explored if inflammatory markers [serum C-reactive protein (CRP) and interleukin-6 (IL-6)] at age 9 years explain the longitudinal association between adverse life events (at ages 1-9 and 9-11 years) and internalising and externalising symptoms (at ages 9 and 11 years). Data (n = 4583) were analysed using cross-lagged panel modelling to take into account reciprocal associations and reverse causality, and path analyses to test for mediation. Gender, ethnicity, body mass index, maternal education, paternal social class and maternal depression were used as potential confounders. RESULTS: CRP was not associated with adverse life events. There was evidence for partial mediation by IL-6 such that exposure to adverse life events was associated with increased levels of IL-6 later, in turn associated with later internalising symptoms. These associations were robust to adjustment for confounders. IL-6 did not explain part of the opposite association, that of earlier internalising symptoms and later life events, nor did it explain either direction of the association between life events and externalising symptoms. CONCLUSION: Our findings suggest a pathway that may connect early psychosocial adversity and childhood internalising symptoms via higher plasma levels of inflammatory markers, such as IL-6.

Correction to: Main and interactive effects of inflammation and perceived neighbourhood cohesion on psychological distress: results from a population-based study in the UK.

The article "Main and interactive effects of inflammation and perceived neighbourhood cohesion on psychological distress: results from a population-based study in the UK", written by "Efstathios Papachristou, Eirini Flouri, Theodora Kokosi and Marta Francesconi", was originally published electronically on the publisher's Internet portal (currently SpringerLink) on 25 February 2019 without open access.

Main and interactive effects of inflammation and perceived neighbourhood cohesion on psychological distress: results from a population-based study in the UK.

PURPOSE: Low neighbourhood cohesion and increased levels of inflammation are independent predictors of psychological distress. In this study we explored if they also interact to predict it. METHODS: Our sample was 9,393 adult participants of the UK Household Longitudinal Study (UKHLS), a large longitudinal household panel study in the UK. Inflammation was measured using C-reactive protein levels. Perceived neighbourhood cohesion was measured using a 13-item questionnaire. Psychological distress was measured with the General Health Questionnaire-12. RESULTS: Perceived neighbourhood cohesion and inflammation retained their significant main effects on psychological distress even after adjustment for confounders (age, gender, ethnicity, partner status, education, smoking status, obesity and urbanicity). The effect of neighbourhood cohesion was larger. However, we did not find evidence for an interactive association between the two. CONCLUSIONS: Perceived neighbourhood cohesion was inversely related to psychological distress, over and above other important person- and neighbourhood-level characteristics. Inflammation was also associated with psychological distress, albeit less strongly. If these associations are causal, they suggest that promoting neighbourhood cohesion can alleviate some of the burden associated with psychological distress.

The quality of air outside and inside the home: associations with emotional and behavioural problem scores in early childhood.

BACKGROUND: This study explored the role of outdoor air pollution [nitrogen dioxide (NO2) and sulphur dioxide (SO2)] and indoor air quality (measured with damp or condensation and secondhand smoke exposures) at age 9 months in emotional, conduct and hyperactivity problems at age 3 years. METHOD: Data from 11,625 Millennium Cohort Study children living in England and Wales were modelled using multilevel regression. RESULTS: After adjusting for a host of confounders, having a damp or condensation problem at home was related to both emotional and conduct problems. Secondhand smoke exposure was associated with all three problem types. Associations with outdoor air pollution were less consistent. CONCLUSIONS: Exposures to damp or condensation and secondhand smoke in the home are likely to be risk factors for child emotional and behavioural problems. Parents should continue to be educated about the dangers of exposing their children to poor air quality at home.