Childhood exposure to particulate matter and nitrogen oxides and associations with mental health disorders in early adulthood: testing mediation by cognition in a UK longitudinal cohort study

We examined the association between childhood poverty and mental health disorders (MHD) in childhood and early adulthood. We also investigated whether the association between poverty in childhood and MHD is mediated by exposure to stressful life events (SLE). We used data from a prospective community cohort of young people assessed at baseline (M = 9.7years, SD = 1.9), first (M = 13.5years, SD = 1.9), and second (M = 18.2years, SD = 2.0) follow-ups (N = 1,590) in Brazil. Poverty was assessed using a standardized classification. Exposure to 20 different SLE was measured using the Life History instrument. Psychiatric diagnoses were evaluated using the Development and Well-Being Assessment. Latent growth models investigated the association between poverty at baseline and the growth of any MHD, externalizing, and internalizing disorders. Mediation models evaluated whether the association between childhood poverty and MHD in early adulthood was mediated by exposure to SLE. Poverty affected 11.4% of the sample at baseline and was associated with an increased propensity for presenting externalizing disorders in adolescence or early adulthood (standardized estimate = 0.27, p = 0.016). This association was not significant for any disorder or internalizing disorders. Childhood poverty increased the likelihood of externalizing disorders in early adulthood through higher exposure to SLE (OR = 1.07, 95 CI% 1.01-1.14). Results were only replicated among females in stratified analyses. Childhood poverty had detrimental consequences on externalizing MHD in adolescence, especially among females. Poverty and SLE are preventable risk factors that need to be tackled to reduce the burden of externalizing disorders in young people.

A majority of adult psychiatric patients have suffered of psychiatric symptoms already during childhood or adolescence. Previous studies on continuity of mental health problems have included only children with diagnoses and thus missed symptomatic children without mental health service contact, or as in longitudinal cohort studies, have suffered from considerable losses of subjects during follow-up. The aim of the present study was to examine the association between multi-informant ratings of childhood psychiatric symptoms and cumulative incidences of diagnosed mental disorders in early adulthood in a large population-based cohort. The original sample consisted of 6,017 Finnish children born in 1981. Parents and teachers completed the Rutter questionnaire, while the children completed the Children's Depression Inventory (CDI) at the age of 8. The follow-up information was obtained from the Finnish Care Register for Health Care. Analyses were done with the Cox regression model. A total of 2,717 males (12.4%) and 2,683 females (12.8%) were diagnosed with a mental disorder in early adulthood. Parent-/teacher-reported high levels (above the 90th percentile) of conduct problems (males, Hazard Ratio (HR)=2.5, 95% CI=1.6-3.7; females, HR=1.5, 95% CI=1.01-2.1) and anxiety (males, HR=1.5, 95% CI=1.1-2.1, females, HR=1.7, 95% CI=1.2-2.4), and child self-reported depressive problems (males, HR=1.7, 95% CI=1.2-2.3; females, HR=1.6, 95% CI=1.1-2.2) were key predictors of any mental disorder in early adulthood. Conduct problems predicted psychotic disorders and substance-related disorders among males. Anxiety problems predicted psychotic disorders, anxiety, and depression. Child self-reported depressive problems predicted male depression. Attention-deficit hyperactivity disorder (ADHD) symptoms and low school performance did not predict any outcome in multivariate analyses. A non-nuclear family living situation at age 8 predicted most outcomes. Adult-reported conduct and emotional problems in children, but not ADHD symptoms, independently predicted mental health service use and any psychiatric diagnosis in late adolescence and early adulthood, emphasizing the need for early identification of childhood mental health problems. Similarly, child self-reports of depressive problems already at age 8 predicted adult outcomes. Our findings emphasize the importance of multi-informant assessment and early targeted interventions for conduct and emotional problems in early school years.

Mental health problems in early adulthood may disrupt partner relationship formation and quality. This prospective study used four waves of Australian data to investigate the effects of depression and anxiety in early adulthood on the quality of future partner (i.e. marriage or cohabiting) relationships. A representative community sample of Australian adults aged 20-24 years was assessed in 1999, 2003, 2007 and 2011. Analyses were restricted to those who at baseline had never entered a marriage or cohabiting relationship with no children (n = 1592). Associations were examined between baseline depression and anxiety levels (using the Goldberg Depression and Anxiety scales) and (a) future relationship status and (b) the quality of marriage or cohabiting relationships recorded at follow-up (up to 12 years later) (partner social support and conflict scales). Depression in early adulthood was associated with never entering a partner relationship over the study period. For those who did enter a relationship, both depression and anxiety were significantly associated with subsequently lower relationship support and higher conflict. Supplementary analyses restricting the analyses to the first relationship entered at follow-up, and considering comorbid anxiety and depression, strongly supported these findings. Depression and anxiety in early adulthood is associated with poorer partner relationship quality in the future. This study adds to evidence showing that mental health problems have substantial personal and inter-personal costs. The findings support the need to invest in prevention and early intervention.

Prospective studies show that the adult outcomes of adolescents who deliberately harm themselves are marked by high rates of adversity and psychiatric disorders. The goal of this study was to identify pathways linking childhood risk factors to early adult outcomes of suicidal adolescents. A clinical sample of 158 adolescents who deliberately poisoned themselves was followed up six years later. Eighty per cent of the cohort (n = 126) were interviewed in early adulthood using a battery of standardised measures of psychopathology and social functioning. Multivariate mediation path analysis identified four pathways linking child and adolescent risk factors to adverse outcomes in early adulthood. Family dysfunction, conduct disorder and hopelessness contributed to the risk of high adversity in early adulthood indirectly through its effect on other risk domains, including dropping out of school and adopting adult roles at a younger age. Hopelessness not only predicted dropping out of school but also independently contributed to the risk of chronic major depressive disorder in early adulthood. Child sexual abuse independently predicted high adversity and chronic major depression over and above the influence of hopelessness. Juvenile onset major depression independently predicted chronic major depression in early adulthood. A substantial proportion of the effects of child sexual abuse and hopelessness on the risk of deliberate self-harm in early adulthood was mediated by high adversity and the duration of major depression. However, chronic major depression was the only risk factor independently associated with deliberate self-harm in adulthood once correlation with adversity was taken into account. Chronic major depressive disorder is central to deliberate self-harm repetition. However, adult outcomes of suicidal adolescents are also dominated by the accumulating effects and consequences of other childhood risk factors, including child sexual abuse and adolescent hopelessness.

Polyunsaturated fatty acids (PUFAs) may be pertinent to the development of mental disorders, for example via modulation of inflammation and synaptogenesis. We wished to examine cross-sectional and longitudinal associations between PUFAs and mental disorders in a large cohort of young people. Participants in the Avon Longitudinal Study of Parents and Children were interviewed and provided blood samples at two sampling periods when approximately 17 and 24 years old. Plasma PUFA measures (total omega-6 [n-6], total omega-3 [n-3], n-6:n-3 ratio and docosahexaenoic acid [DHA] percentage of total fatty acids) were assessed using nuclear magnetic resonance spectroscopy. Cross-sectional and longitudinal associations between standardised PUFA measures and three mental disorders (psychotic disorder, moderate/severe depressive disorder and generalised anxiety disorder [GAD]) were measured by logistic regression, adjusting for age, sex, body mass index and cigarette smoking. There was little evidence of cross-sectional associations between PUFA measures and mental disorders at age 17. At age 24, the n-6:n-3 ratio was positively associated with psychotic disorder, depressive disorder and GAD, while DHA was inversely associated with psychotic disorder. In longitudinal analyses, there was evidence of an inverse association between DHA at age 17 and incident psychotic disorder at age 24 (adjusted odds ratio 0.44, 95% confidence interval 0.22–0.87) with little such evidence for depressive disorder or GAD. There was little evidence for associations between change in PUFA measures from 17 to 24 years and incident mental disorders at 24 years. These findings provide support for associations between PUFAs and mental disorders in early adulthood, and in particular, for DHA in adolescence in relation to prevention of psychosis.

Growing evidence associates air pollution exposure with various psychiatric disorders. However, the importance of early-life (eg, prenatal) air pollution exposure to mental health during youth is poorly understood, and few longitudinal studies have investigated the association of noise pollution with youth mental health. To examine the longitudinal associations of air and noise pollution exposure in pregnancy, childhood, and adolescence with psychotic experiences, depression, and anxiety in youths from ages 13 to 24 years. This cohort study used data from the Avon Longitudinal Study of Parents and Children, an ongoing longitudinal birth cohort founded in 1991 through 1993 in Southwest England, United Kingdom. The cohort includes over 14 000 infants with due dates between April 1, 1991, and December 31, 1992, who were subsequently followed up into adulthood. Data were analyzed October 29, 2021, to March 11, 2024. A novel linkage (completed in 2020) was performed to link high-resolution (100 m2) estimates of nitrogen dioxide (NO2), fine particulate matter under 2.5 μm (PM2.5), and noise pollution to home addresses from pregnancy to 12 years of age. Psychotic experiences, depression, and anxiety were measured at ages 13, 18, and 24 years. Logistic regression models controlled for key individual-, family-, and area-level confounders. This cohort study included 9065 participants who had any mental health data, of whom (with sample size varying by parameter) 51.4% (4657 of 9051) were female, 19.5% (1544 of 7910) reported psychotic experiences, 11.4% (947 of 8344) reported depression, and 9.7% (811 of 8398) reported anxiety. Mean (SD) age at follow-up was 24.5 (0.8) years. After covariate adjustment, IQR increases (0.72 μg/m3) in PM2.5 levels during pregnancy (adjusted odds ratio [AOR], 1.11 [95% CI, 1.04-1.19]; P = .002) and during childhood (AOR, 1.09 [95% CI, 1.00-1.10]; P = .04) were associated with elevated odds for psychotic experiences. Pregnancy PM2.5 exposure was also associated with depression (AOR, 1.10 [95% CI, 1.02-1.18]; P = .01). Higher noise pollution exposure in childhood (AOR, 1.19 [95% CI, 1.03-1.38]; P = .02) and adolescence (AOR, 1.22 [95% CI, 1.02-1.45]; P = .03) was associated with elevated odds for anxiety. In this longitudinal cohort study, early-life air and noise pollution exposure were prospectively associated with 3 common mental health problems from adolescence to young adulthood. There was a degree of specificity in terms of pollutant-timing-outcome associations. Interventions to reduce air and noise pollution exposure (eg, clean air zones) could potentially improve population mental health. Replication using quasi-experimental designs is now needed to shed further light on the underlying causes of these associations.

Childhood Predictors of Psychiatric Disorders Among Boys: A Prospective Community-Based Follow-up Study From Age 8 Years to Early Adulthood

Parental mental disorders have been shown to predict offspring's mental health problems. We examined whether pathways from parental mental disorders to offspring's psychiatric work disability in early adulthood are mediated through offspring's mental disorders and social disadvantage in adolescence. Study population consisted of the 1987 Finnish Birth Cohort. Data on parents' psychiatric care or work disability due to mental diagnosis between 1987 and 2000 and the cohort participants' health and social factors between 2001 and 2005 were derived from administrative national registers. From 2006 through 2015, 52,182 cohort participants were followed for admittance of psychiatric work disability due to depressive or anxiety disorders. First, we applied a pathway analysis to examine the occurrence of each path. We then used mediation analysis to assess the proportion of association between parental mental disorders and work disability mediated by offspring's health and social disadvantage. The pathway model indicated that the association from parental mental disorders to offspring's work disability due to depressive or anxiety disorder is through mental disorders and social disadvantage in adolescence. Odds Ratio for the total effect of parental mental disorders on offspring's psychiatric work disability was 1.85 (95% confidence interval [CI] 1.46-2.34) in the model including offspring's mental disorders that mediated this association by 35%. Corresponding results were 1.86 (95% CI 1.47-2.35) and 28% for social disadvantage in adolescence. These findings suggest that intergenerational determination of work disability due to mental disorders could be addressed by actions supporting mental health and social circumstances in adolescence.

Our goal was to study predictive associations between bullying and victimization at age 8 years and psychiatric disorders in early adulthood. The sample comprised 2540 boys born in 1981. Information about bullying and victimization was gathered in 1989 when the boys were 8 years old from parents, teachers, and children. Information about psychiatric disorders was based on military call-up examination and army registry when the subjects were 18 to 23 years old. In univariate logistic regression analysis, frequent bullying-only status predicted antisocial personality, substance abuse, and depressive and anxiety disorders; frequent victimization-only status predicted anxiety disorder, whereas frequent bully-victim status predicted antisocial personality and anxiety disorder. When controlled against the effects of parental education level and parent and teacher reports of emotional and behavioral symptoms by using Rutter scales, frequent victimization-only status predicted anxiety disorders, and frequent bullying-only predicted antisocial personality disorder, whereas frequent bully-victimization predicted both anxiety and antisocial personality disorder. Information about frequent bullying and victimization as primary screening for children at risk identified approximately 28% of those with a psychiatric disorder 10 to 15 years later. Both bullying and victimization during early school years are public health signs that identify boys who are at risk of suffering psychiatric disorders in early adulthood. The school health and educational system has a central role to play in detecting these boys at risk.

BackgroundLow-grade inflammation may occur in association with several mental disorders of early adulthood, though associations with markers of chronic inflammation such as soluble urokinase plasminogen activator receptor (suPAR) are less well-established. We aimed to examine associations between acute and chronic inflammatory markers and mental disorders, as well as psychiatric co-morbidity, in young adults aged 24 years in the Avon Longitudinal Study of Parents and Children. MethodsIncluded were 781 participants (of 4019 who attended at age 24 years) who completed psychiatric assessments and provided plasma samples. Of these, 377 met criteria for psychotic disorder, depressive disorder or generalised anxiety disorder and 404 did not. Plasma concentrations of IFN-γ, IL-6, IL-8, IL-10, TNF-α, CRP, sVCAM1, sICAM1, suPAR and alpha-2-macroglobulin were measured using immunoassays. Logistic regression compared standardised inflammatory marker levels in cases and controls. Negative binomial regression evaluated associations between inflammatory markers and co-morbidity (number of mental disorders). Models were adjusted for sex, body mass index, cigarette smoking, cannabis use and employment status, then additionally for childhood trauma. ResultsFor psychotic disorder, there was evidence for associations with IL-6 (odds ratio[OR] 1.68, 95 %CI 1.20–2.34) and suPAR (OR 1.74, 95 %CI 1.17–2.58). There was weaker evidence for an association between suPAR and depressive disorder (OR 1.31, 95 %CI 1.05–1.62). There was little evidence for associations between inflammatory markers and generalised anxiety disorder. There was weak evidence for an association between suPAR and co-morbidity (β 0.10, 95 %CI 0.01–0.19). There was little evidence for additional confounding by childhood trauma. ConclusionsThere was evidence that 24-year-olds with psychotic disorder had raised plasma IL-6 and suPAR concentrations compared to controls. These findings have implications regarding the role of inflammation in mental disorders in early adulthood.

The relationship between parental involvement in childhood and depression in early adulthood

ABSTRACTObjectiveThe aim of this study was to explore changes in the incidences of childhood and early adulthood hospital‐treated psychiatric disorders in five large Finnish birth cohorts of individuals born between 1966 and 1997.MethodsThe five birth cohorts were as follows: Northern Finland Birth Cohort 1966 (NFBC 1966) and 1986 (NFBC 1986), 1987 Finnish Birth Cohort (FBC 1987) and 1997 (FBC 1997), and Finnish 1981 Birth Cohort Study (FBCS 1981). Incidences of hospital‐treated psychiatric disorders in each cohort were calculated separately for males (N = 71,209) and females (N = 65,190). Poisson regression was used to test difference in proportions of psychiatric disorders in wide range of diagnosis classes separately in childhood and adolescence, and early adulthood.ResultsThe total incidences of psychiatric disorders in childhood and adolescence among males has increased in the birth cohorts over decades (Incidence Rate Ratio, IRR = 1.04 (1.04–1.05); p < 0.001). Similar result was seen among females (IRR = 1.04 (1.03–1.04); p < 0.001). In early adulthood, there was significant increase among females (IRR = 1.04 (1.03–1.05); p < 0.001), but among males, the change was not significant (IRR = 0.99 (0.99–1.00), p = 0.051).ConclusionsThe main finding was that the cumulative incidence of hospital‐treated psychiatric disorders increased over the decades in Finland. The increasing trend in hospital‐treated psychiatric disorders in early adulthood was detected in females but not in males. In the youngest cohorts, the cumulative incidence of hospital‐treated psychiatric disorders was at the same level in males and females, whereas in oldest cohort, males had higher incidence than females.

To assess the associations of intoxication frequency and number of drinks needed to become intoxicated in mid-adolescence with onset of psychiatric disorders in early adulthood. Prospective cohort study in Northern Finland, with people from the Northern Finland Birth Cohort 1986 who self-reported adolescent alcohol use: 6548 subjects (69.4% of the original sample). Data on alcohol use were collected using questionnaires at ages 15-16years. Outcomes were any non-organic psychosis, mood disorder, anxiety disorder, any substance use disorder (SUD) and all the studied psychiatric disorders in early adulthood gathered from nation-wide health care, pension and insurance registers. Number of drinks needed to become intoxicated was categorized into three classes: (1) no alcohol use or intoxication, and (2) low and (3) high alcohol tolerance (more than seven/nine drinks for females/males) groups. Similarly, intoxication frequency was divided into three classes: (1) never, (2) one to two times and (3) three or more times during the past 30days. Information regarding gender, family type, other drug use, psychopathology using Youth Self-Report (YSR) total score and parental psychiatric disorders were used as covariates. In the multivariable analyses, both low [odds ratio (OR)=3.0, 95% confidence interval (CI)=1.3-6.7, P-value=0.009] and high (OR=4.4, 95% CI=1.8-11.1, P-value=0.001) alcohol tolerance were associated with increased risk of SUD. More frequent intoxication was associated with increased frequency of SUD (OR=3.9, 95% CI=2.0-7.3, P-value <0.001) and mood disorder (OR=1.6, 95% CI=1.1-2.3, P-value=0.008). The latter was attenuated after adjusting with concurrent psychopathology (YSR) and other drug use. Both higher alcohol tolerance and frequent intoxication in adolescence appear to be associated with increased risk of future substance use disorder.

The childhood family environment is a determinant of mental health outcomes later in life. Yet, few studies have examined its role in outcomes such as depression in early adulthood, especially in low- and middle-income countries such as Botswana. This study explores the relationship between childhood family environmental factors and depression among young adults in Botswana. A sample of 351 students at the University of Botswana was surveyed through a self-administered questionnaire, which included various childhood environmental factors, the Beck Depression Inventory-II and socio-demographic items. Descriptive statistics, t-tests and regression models were used in the data analyses. About one in four young adults reported moderate to severe symptoms of depression with about one in ten in the severe category. Childhood alcohol use, parental drug and alcohol use, physical assault, and psychological aggression towards parents or guardians during childhood, all significantly predicted symptoms of depression in early adulthood. Altogether, the childhood family environmental factors and gender explained significant variance in depressive symptoms. Multiple adverse childhood environments constitute significant risk factors for depression in early adulthood and the next generation. Preventive and early intervention services for vulnerable children, evaluation of mental health, childhood family experiences, and creating awareness of the need for treatment are critical. Cognitive behavioural therapy and mindfulness training are possible strategies to reduce the life-course effects of adverse childhood family environmental factors on depression in young adults.

Early adulthood is vulnerable to depression. This period is characterized by substantial transitions, including pursuing higher education, entering the workforce, and forming intimate relationships, which can contribute to vulnerability to mental health disorders. Self-compassion and loneliness are factors associated with a tendency toward depression, including in early adulthood. This study aims to analyze the relationship between self-compassion, loneliness, and depression in early adulthood. This research employs a quantitative correlational approach. Data were obtained from 387 early adult participants using researcher-developed scales measuring depressive tendencies, self-compassion, and loneliness. Data analysis was conducted using the non-parametric Spearman analysis technique. The results indicate that self-compassion has a significant negative correlation with depression, while loneliness has a significant positive correlation with the tendency toward depression in early adulthood