The double jeopardy of low family income and negative emotionality: The family stress model revisited.

The family stress model has, for decades, guided empirical work linking poverty with increased risk of child social-emotional dysfunction. The present study extends this line of work by examining whether child negative emotionality moderates associations between family income, family stress (maternal distress, parental locus of control, and relationship dissatisfaction), and later externalizing and internalizing behavior problems. In a longitudinal population-based sample (n ~ 80,000) of Norwegian children followed from birth through age five (The Norwegian Mother, Father, and Child Cohort Study; MoBa), we examined whether high (vs. moderate or low) negative emotionality families would display: (a) compounding stress (i.e., particularly strong associations between low family income and family stress), (b) diathesis-stress (i.e., particularly strong associations between family stress and behavior problems), or (c) double jeopardy (i.e., both compounding stress and diathesis-stress moderating effects). Negative emotionality significantly moderated the association between family income and behavior problems in a manner most consistent with double jeopardy. As a result, compared with children with moderate/low negative emotionality, the family income-behavior problems association was two to three times larger for those with higher negative emotionality. These findings underscore the active role children may play in family processes that link low family income with behavior problems.

Effect of Pharmacological Treatment of Attention-Deficit/Hyperactivity Disorder on Criminality.

OBJECTIVE: Criminality rates are higher among persons with attention-deficit/hyperactivity disorder (ADHD), and evidence that medication reduces crime is limited. Medication rates between clinics vary widely even within universal health care systems, partly because of providers' treatment preferences. We used this variation to estimate causal effects of pharmacological treatment of ADHD on 4-year criminal outcomes. METHOD: We used Norwegian population-level registry data to identify all unique patients aged 10 to 18 years diagnosed with ADHD between 2009 and 2011 (n = 5,624), their use of ADHD medication, and subsequent criminal charges. An instrumental variable design, exploiting variation in provider preference for ADHD medication between clinics, was used to identify causal effects of ADHD medication on crime among patients on the margin of treatment, that is, patients who receive treatment because of their provider's preference. RESULTS: Criminality was higher in patients with ADHD relative to the general population. Medication preference varied between clinics and strongly affected patients' treatment. Instrumental variable analyses supported a protective effect of pharmacological treatment on violence-related and public-order-related charges with numbers needed to treat of 14 and 8, respectively. There was no evidence for effects on drug-, traffic-, sexual-, or property-related charges. CONCLUSION: This is the first study to demonstrate causal effects of pharmacological treatment of ADHD on some types of crimes in a population-based natural experiment. Pharmacological treatment of ADHD reduced crime related to impulsive-reactive behavior in patients with ADHD on the margin of treatment. No effects were found on crimes requiring criminal intent, conspiracy, and planning. STUDY PREREGISTRATION INFORMATION: The ADHD controversy project: Long-term effects of ADHD medication; https://www.isrctn.com/; 11891971.

Childhood personality and academic performance: A sibling fixed-effects study.

OBJECTIVE: This study investigated the associations between personality traits at age 8 and academic performance between ages 10 and 14, controlling for family confounds. BACKGROUND: Many studies have shown links between children's personality traits and their school performance. However, we lack evidence on whether these associations remain after genetic and environmental confounders are accounted for. METHOD: Sibling data from the Norwegian Mother and Child Cohort Study (MoBa) were used (n = 9701). First, we estimated the overall associations between Big Five personality traits and academic performance, including literacy, numeracy, and foreign language. Second, we added sibling fixed effects to remove unmeasured confounders shared by siblings as well as rating bias. RESULTS: Openness to Experience (between-person ß = 0.22 [95% CI: 0.21-0.24]) and Conscientiousness (between-person ß = 0.18 [95% CI 0.16-0.20]) were most strongly related to educational performance. Agreeableness (between-person ß = 0.06 [95% CI -0.08-0.04]) and Extraversion (between-person ß = 0.02 [95% CI 0.00-0.04]) showed small associations with educational performance. Neuroticism had a moderate negative association (between-person ß = -0.14 [95% CI -0.15-0.11]). All associations between personality and performance were robust to confounding: the within-family estimates from sibling fixed-effects models overlapped with the between-person effects. Finally, childhood personality was equally predictive of educational performance across ages and genders. CONCLUSIONS: Although family background is influential for academic achievement, it does not confound associations with personality. Childhood personality traits reflect unbiased and consistent individual differences in educational potential.

Effect of ADHD medication on risk of injuries: a preference-based instrumental variable analysis.

ADHD is associated with an increased risk of injury. Causal evidence for effects of pharmacological treatment on injuries is scarce. We estimated effects of ADHD medication on injuries using variation in provider preference as an instrumental variable (IV). Using Norwegian registry data, we followed 8051 patients who were diagnosed with ADHD aged 5 to 18 between 2009 and 2011 and recorded their ADHD medication and injuries treated in emergency rooms and emergency wards up to 4 years after diagnosis. Persons with ADHD had an increased risk of injuries compared to the general population (RR 1.35; 95% CI: 1.30-1.39), with higher risk in females (RR 1.47; 95% CI: 1.38-1.56) than males (RR 1.23; 95% CI: 1.18-1.28). The between-clinics variation in provider preference for ADHD medication was large and had a considerable impact on patients' treatment status. There was no causal evidence for protective effects of pharmacological treatment on injuries overall for young individuals with ADHD characterized by milder or atypical symptoms. However, there was an apparent effect of pharmacological treatment over time on the risk of injuries treated at emergency wards in this patient group.

Boys with overweight status lagged behind girls with overweight status in reading: evidence from mendelian randomization.

OBJECTIVES: We investigated the relationship between childhood weight status and academic achievement across sexes and different school subjects in Norway. STUDY DESIGN AND SETTING: We used data from the Norwegian Mother, Father and Child Cohort Study (MoBa), which includes genetic data (N = 13,648, 8-year-old children). We employed within-family mendelian randomization, using a body mass index (BMI) polygenic risk score as an instrument to address unobserved heterogeneity. RESULTS: Contrary to most previous findings, we observed that overweight status (including obesity) has more detrimental effects on reading achievement in boys than in girls; the test scores of boys with overweight were about a standard deviation lower than those of normal weight boys, and the negative effects on reading achievement became stronger in the later grade. CONCLUSION: Previous obesity prevention studies have mainly targeted girls, based on the assumption that the obesity penalty is greater for girls. Our findings highlight that particular attention to boys with overweight may help reduce the existing gender gap in academic achievement.

Variation in attitudes toward diagnosis and medication of ADHD: a survey among clinicians in the Norwegian child and adolescent mental health services.

Prevalence and medication rates of ADHD vary geographically, both between and within countries. No absolute cutoff exists between ADHD and normal behavior, making clinician attitudes (leading to local practice cultures) a potential explanation for the observed variation in diagnosis and medication rates. The objective of this study was to describe variation in attitudes toward diagnosis and medication of ADHD among clinicians working in child and adolescent mental health services (CAMHS). We hypothesized that attitudes would vary along a spectrum from "restrictive" to "liberal". We also explored whether differences in attitudes between clinicians were related to professional background and workplace (clinic). A survey in the form of a web-based questionnaire was developed. All CAMHS outpatient clinics in Norway were invited. Potential respondents were all clinicians involved in diagnosing and treating children and adolescents with ADHD. To investigate the existence of attitudes toward diagnosis and medication as latent constructs, we applied confirmatory factor analysis (CFA). We further examined how much of variance in attitudes could be ascribed to profession and clinics by estimating intraclass correlation coefficients. In total, 674 respondents representing 77 (88%) of the clinics participated. We confirmed variation in attitudes with average responses leaning toward the "restrictive" end of the spectrum. CFA supported "attitude toward diagnosis" and "attitude toward medication" as separate, and moderately correlated (r = 0.4) latent variables, representing a scale from restrictive to liberal. Professional background and workplace explained only a small part of variance in these attitudes.

Geographical variation in ADHD: do diagnoses reflect symptom levels?

Rates of ADHD diagnosis vary across regions in many countries. However, no prior study has investigated how much within-country geographic variation in ADHD diagnoses is explained by variation in ADHD symptom levels. We examine whether ADHD symptom levels explain variation in ADHD diagnoses among children and adolescents using nationwide survey and register data in Norway. Geographical variation in incidence of ADHD diagnosis was measured using Norwegian registry data from the child and adolescent mental health services for 2011-2016. Geographical variation in ADHD symptom levels in clinics' catchment areas was measured using data from the Norwegian mother, father and child cohort study for 2011-2016 (n = 39,850). Cross-sectional associations between ADHD symptom levels and the incidence of ADHD diagnoses were assessed with fractional response models. Geographical variation in ADHD diagnosis rates is much larger than what can be explained by geographical variation in ADHD symptoms levels. Treatment in the Norwegian child and adolescent mental health services is free, universally available upon referral, and practically without competition from the private sector. Factors beyond health care access and unequal symptom levels seem responsible for the geographical variation in ADHD diagnosis.

A Gentle Introduction to Instrumental Variables.

Instrumental variables (IV) is a central strategy for identifying causal effects in absence of randomized experiments. Clinicians and epidemiologists may find the intuition of IV easy to grasp by comparison to randomized experiments. Randomization is an ideal IV because treatment is assigned randomly, and hence unaffected by everything else. IV methods in nonexperimental settings mimic a randomized experiment by using a source of "as good as" random variation in treatment instead. The main challenge with IV designs is to find IVs that are as good as randomization. Discovering potential IVs require substantive knowledge and an understanding of design principles. Moreover, IV methods recover causal effects for a subset of the population who take treatment when induced by the IV. Sometimes these estimates are informative, other times their relevance is questionable. We provide an introduction to IV methods in clinical epidemiology. First, we introduce the main principles and assumptions. Second, we present practical examples based on Mendelian randomization and provider preference and refer to other common IVs in health. Third, practical steps in IV analysis are presented. Fourth, the promise and perils of IV methods are discussed. Finally, we suggest further readings.

Adult outcomes of sustained high-quality early child care and education: Do they vary by family income?

Experimental research demonstrates sustained high-quality early care and education (ECE) can mitigate the consequences of poverty into adulthood. However, the long-term effects of community-based ECE are less known. Using the 1991 NICHD Study of Early Child Care and Youth Development (n = 994; 49.7% female; 73.6% White, 10.6% African American, 5.6% Latino, 10.2% Other), results show that ECE was associated with reduced disparities between low- and higher-income children's educational attainment and wages at age 26. Disparities in college graduation were reduced the more months that low-income children spent in ECE (d = .19). For wages, disparities were reduced when children from low-income families attended sustained high-quality ECE (d = .19). Findings suggest that community-based ECE is linked to meaningful educational and life outcomes, and sustained high-quality ECE is particularly important for children from lower-income backgrounds.

Preference-based instrumental variables in health research rely on important and underreported assumptions: a systematic review.

OBJECTIVE: Preference-based instrumental variables (PP IV) designs can identify causal effects when patients receive treatment due to variation in providers' treatment preference. We offer a systematic review and methodological assessment of PP IV applications in health research. STUDY DESIGN AND SETTING: We included studies that applied PP IV for evaluation of any treatment in any population in health research (PROSPERO: CRD42020165014). We searched within four databases (Medline, Web of Science, ScienceDirect, SpringerLink) and four journals (including full-text and title and abstract sources) between January 1, 1998, and March 5, 2020. We extracted data on areas of applications and methodology, including assumptions using Swanson and Hernan's (2013) guideline. RESULTS: We included 185 of 1087 identified studies. The use of PP IV has increased, being predominantly used for treatment effects in cancer, cardiovascular disease, and mental health. The most common PP IV was treatment variation at the facility-level, followed by physician- and regional-level. Only 12 percent of applications report the four main assumptions for PP IV. Selection on treatment may be a potential issue in 46 percent of studies. CONCLUSION: The assumptions of PP IV are not sufficiently reported in existing work. PP IV-studies should use reporting guidelines.

Causal modelling of variation in clinical practice and long-term outcomes of ADHD using Norwegian registry data: the ADHD controversy project.

INTRODUCTION: Attention-deficit/hyperactivity disorder (ADHD) is among the most common mental disorders in children and adolescents, and it is a strong risk factor for several adverse psychosocial outcomes over the lifespan. There are large between-country and within-country variations in diagnosis and medication rates. Due to ethical and practical considerations, a few studies have examined the effects of receiving a diagnosis, and there is a lack of research on effects of medication on long-term outcomes.Our project has four aims organised in four work packages: (WP1) To examine the prognosis of ADHD (with and without medication) compared with patients with other psychiatric diagnoses, patients in contact with public sector child and adolescent psychiatric outpatient clinics (without diagnosis) and the general population; (WP2) Examine within-country variation in ADHD diagnoses and medication rates by clinics' catchment area; and(WP3) Identify causal effects of being diagnosed with ADHD and (WP4) ADHD medication on long-term outcomes. METHOD AND ANALYSIS: Our project links several nationwide Norwegian registries. The patient sample is all persons aged 5-18 years that were in contact with public sector child and adolescent psychiatric outpatient clinics in 2009-2011. Our comparative analysis of prognosis will be based on survival analysis and mixed-effects models. Our analysis of variation will apply mixed-effects models and generalised linear models. We have two identification strategies for the effect of being diagnosed with ADHD and of receiving medication on long-term outcomes. Both strategies rely on using preference-based instrumental variables, which in our project are based on provider preferences for ADHD diagnosis and medication. ETHICS AND DISSEMINATION: The project is approved by the Regional Ethics Committee, Norway (REC number 2017/2150/REC south-east D). All papers will be published in open-access journals and results will be presented in national and international conferences. TRIAL REGISTRATION NUMBERS: ISRCTN11573246 and ISRCTN11891971.

Mechanisms linking parental educational attainment with child ADHD, depression, and academic problems: a study of extended families in The Norwegian Mother, Father and Child Cohort Study.

BACKGROUND: Low educational attainment in parents is associated with child psychopathology. It is not clear whether the associations are due to risk factors that family members share or due to effects of maternal or paternal education on the offspring. We investigate whether associations between maternal and paternal educational attainment and child symptoms of attention deficit/hyperactivity disorder (ADHD), depression, and academic problems are due to shared genetic factors, shared family environmental factors, or effects of the parental phenotype educational attainment itself. METHODS: This study is based on the Norwegian Mother, Father and Child Cohort Study (MoBa). The sample comprised 34,958 children (17,128 girls) in 28,372 extended-family units. We used data from related nuclear families linked by siblings in the parent generation. We applied a quasi-experimental extended children-of-twins design that included siblings in both generations and took account of nonrandom mating by including partners. Educational attainment was self-reported by mothers and fathers. Mothers reported children's symptoms of ADHD, symptoms of depression, and academic problems by questionnaire when the children were 8 years old. RESULTS: Children of lowly educated parents scored higher on all outcomes and had an approximate doubling of the risk of high symptom levels. The association between maternal and paternal educational attainment and child symptoms of ADHD and academic problems persisted after controlling for shared genetic and family environmental factors. Phenotypic transmission to depression was weaker and in the best fitting model fully explained by genetic factors shared by the two generations. CONCLUSIONS: Associations between educational attainment of mothers and fathers and child symptoms of ADHD and academic problems could not be ascribed to shared familial risk factors, whereas associations with symptoms of depression could. Parental education or resources and behaviors resulting from low education might be targets of interventions aimed at reducing symptoms of ADHD and academic problems.

Three Randomized Effectiveness Trials - One Question: Can Callous-Unemotional Traits in Children Be Altered?

Children with conduct problems and callous-unemotional (CU) traits are at risk for multiple problems. Outcome research and mediation analyses testing for mechanisms of change in CU traits have been limited. We examined whether parent training-in a short-term (Brief Parent Training; BPT) or a comprehensive format (Parent Management Training, Oregon Model; PMTO)-or child-directed social skills training (Individual Social Skills Training [ISST]) produced positive effects on CU traits. In mediation models we tested parenting practices as mechanisms of change for CU traits. We pooled data from three randomized effectiveness trials, and 551 families were included in this study. Families had children between 3 and 12 years of age and displayed emerging or present conduct problems at home, day care, or school (BPT M age = 7.28, 31.9% girls; PMTO M age = 8.56, 36.5% girls; ISST M age = 7.64, 19.7% girls). Assessments were completed preintervention, postintervention, and at follow-up (6 months following intervention). Both BPT (d = .32) and PMTO (d = .39) had positive effects on CU traits at posttest, whereas ISST did not (d = -.06). At follow-up, only PMTO produced a significant effect (d = .48) on CU traits. A significant indirect effect on CU traits emerged by positive parenting. Both parent training conditions outperformed ISST. Only PMTO maintained its effects at follow-up. The findings suggest that PMTO can reduce CU traits and that improved positive parenting is associated with positive outcomes for children's CU traits.

Economic volatility in childhood and subsequent adolescent mental health problems: a longitudinal population-based study of adolescents.

OBJECTIVE: The aim of the current paper was to investigate the association between the patterns of duration, timing and sequencing of exposure to low family income during childhood, and symptoms of mental health problems in adolescence. SETTING: Survey administered to a large population-based sample of Norwegian adolescents. PARTICIPANTS: Survey data from 9154 participants of 16-19 years age (53% participation rate; 52.7% girls) were linked to registry-based information about childhood family income from tax return data. OUTCOME MEASURES: Mental health outcomes were symptoms of emotional, conduct, hyperactivity, peer problems and general mental health problems measured with the Strengths and Difficulties Questionnaire, symptoms of depression measured with Short Mood and Feelings Questionnaire and symptoms of attention-deficit/hyperactivity disorder (ADHD) measured with the Adult ADHD Self-Report Scale. RESULTS: Latent class analysis and the BCH approach in Mplus were used to examine associations between patterns of poverty exposure and mental health outcomes. Four latent classes of poverty exposure emerged from the analysis. Participants moving into poverty (2.3%), out of poverty (3.5%) or those chronically poor (3.1%) had more symptoms of mental health problems (Cohen's d=16-.50) than those with no poverty exposure (91.1%). This pattern was, however, not found for symptoms of ADHD. The pattern of results was confirmed in robustness checks using observed data. CONCLUSIONS: Exposure to poverty in childhood was found to be associated with most mental health problems in adolescence. There was no strong suggestion of any timing or sequencing effects in the patterns of associations.

Is Affluence a Risk for Adolescents in Norway?

Studies suggest that affluence poses a risk for adolescents, but this has rarely been studied outside the United States. We examined the unique and additive roles of family and school affluence for adolescent outcomes among 10th-grade students (n = 7,203) in Oslo, Norway. Multilevel models were estimated separately by gender. For both boys and girls, school affluence was a risk for alcohol abuse and family affluence was a risk for conduct problems, although for conduct the risk was only at the very highest end of income distribution and adolescents in very poor families were also at risk. There was also a complex pattern of risk for early sexual debut; family affluence posed risk, but school affluence appeared protective.

Maternal perinatal and concurrent depressive symptoms and child behavior problems: a sibling comparison study.

BACKGROUND: Previous studies have found significant associations between maternal prenatal and postpartum depression and child behavior problems (CBP). The present study investigates whether associations remain in a prospective, longitudinal design adjusted for familial confounding. METHODS: The sample comprised 11,599 families including 17,830 siblings from the Norwegian Mother and Child Cohort study. Mothers reported depressive symptoms at gestational weeks 17 and 30, as well as 6 months, 1.5, 3, and 5 years postpartum. Fathers' depression was measured at gestational week 17. At the last three time-points, child internalizing and externalizing problems were concurrently assessed. We performed multilevel analyses for internalizing and externalizing problems separately, using parental depression as predictors. Analyses were repeated using a sibling comparison design to adjust for familial confounding. RESULTS: All parental depressive time-points were significantly and positively associated with child internalizing and externalizing problems. After sibling comparison, however, only concurrent maternal depression was significantly associated with internalizing [estimate = 2.82 (1.91-3.73, 95% CI)] and externalizing problems [estimate = 2.40 (1.56-3.23, 95% CI)]. The effect of concurrent maternal depression on internalizing problems increased with child age. CONCLUSIONS: Our findings do not support the notion that perinatal maternal depression is particularly detrimental to children's psychological development, as the most robust effects were found for maternal depression occurring during preschool years.

Low Family Income and Behavior Problems in Norwegian Preschoolers: Is Child Emotionality a Marker for Sensitivity of Influence?

UNLABELLED: Poor children have higher rates of mental health problems than more affluent peers, also in progressive welfare states such as Norway. Temperamental characteristics may render some children more sensitive to the adverse influence of poor economy. OBJECTIVE: This study examined the direct associations between family income-to-needs and mental health and assessed moderation by early temperamental characteristics (i.e., emotionality). METHOD: Using data from the Norwegian Mother and Child Cohort Study, associations between income-to-needs across children's first 3 years and internalizing and externalizing problems when children were 5 years old were examined. Differential sensitivity to family income-to-needs was assessed by investigating how emotionality, when children were one-and-a-half and 3 years old, moderated these associations. RESULTS: Significant main effects of income-to-needs and emotionality and a significant interaction effect between income-to-needs and emotionality were found for externalizing problems, but not for internalizing problems. CONCLUSION: Children in poor families with an emotionally reactive temperament had higher scores on externalizing problems when they were 5 compared with their less emotionally reactive peers.

Age of Entry Into Early Childhood Education and Care as a Predictor of Aggression: Faint and Fading Associations for Young Norwegian Children.

Socioemotional risks associated with nonparental care have been debated for decades, and research findings continue to be mixed. Yet few studies have been able to test the causal hypothesis that earlier, more extensive, and longer durations of nonmaternal care lead to more problems. To examine the consequences of age of entry into nonparental care for childhood aggression, we used prospective longitudinal data from Norway, where month of birth partly determines age of entry into Early Childhood Education and Care (ECEC) centers. In this sample of 939 children followed from ages 6 months through 4 years, ECEC teachers reported the children's aggression when they were 2, 3, and 4 years old. We found some evidence that age of entry into ECEC predicted aggression at age 2, albeit modestly and not robustly. Between the ages of 2 and 4 years, the effect of age of entry on aggression faded to negligible levels. The implications for psychological science and policy are discussed.

Normative development of physical aggression from 8 to 26 months.

This study investigated the normative use and developmental course of physical aggression (PA), defined as use of physical force such as hitting, biting, and kicking, from 8 to 26 months and predictors thereof. We used data from the Behavior Outlook Norwegian Developmental Study, comprising 1,159 children (559 girls and 600 boys). Both mothers and fathers reported frequently about their child's use of PA in personal and telephone interviews. Mean number of reports per child was 7.16 (SD 1.70), with 90% having at least 6 reports. We employed Rasch scaling to construct a single linear PA measure and multilevel growth curve modeling to address the research questions. The results confirm that the development of PA is nonlinear, with a peak in frequency at about 20-22 months, which is followed by a decline toward 26 months. There is both within- and between-child variance in the development of PA. Higher levels of PA were predicted by the presence of a same-age sibling, maternal and paternal mental distress, and difficult child temperament (high activity level and distress due to limitations), whereas the main effect of gender was only trend-significant. Growth of PA across this developmental period was predicted by the presence of a same-age sibling and high activity level. The results both support and transcend previous research within this field.

Family concordance and gender differences in parent-child structured interaction at 12 months.

This observational study examined family concordance and gender differences in early parent-child interaction in the family supportive sociopolitical context of Norway. Mothers and fathers from 39 Norwegian families were observed on separate occasions with their 12-month-old children (20 girls and 19 boys). Data were recorded from observations using microsocial coding methodology based on social interaction learning theory. We found no within-family concordance between mothers' and fathers' behaviors with their child. The children's negative engagement with each parent was moderately correlated. For parents with boys, fathers were overall more positively engaged than mothers. Moreover, fathers of boys displayed more positive engagement than those of girls, whereas mothers of girls and boys displayed similar levels of positive engagement. In contrast to previous findings, mothers did not verbalize more than fathers. Girls were overall more positively engaged during interaction with both mothers and fathers than boys. Thus, in a sociopolitical context that facilitates early parent-child relationships and gender equality, there were few but noteworthy gender differences in parent-child interaction at 12 months.