Floor V. A. van Oort

Material, psychosocial, and behavioural factors in the explanation of educational inequalities in mortality in the Netherlands

Study objectives: To assess the direct and indirect contributions of material, behavioural, and psychosocial factors to the explanation of educational inequalities in mortality simultaneously. Design: Prospective observational study (1991–1998). Setting: General population from south east Netherlands. Participants: 3979 men and women aged 15–74 years without severe chronic disease at baseline (1991). Main results: Material factors (type of health insurance, financial problems, and housing tenure), psychosocial factors (life events and external locus of control), and behavioural factors (smoking habits and physical activity) together reduced the relative risk of mortality of the lowest educated group from 2.57 (95%CI 1.43 to 4.64) to 1.01 (95%CI 0.50 to 2.03). Of these three groups of factors, material factors contributed most to the educational inequalities. Part of the contribution of material factors was via psychosocial factors and part via behavioural factors. Psychosocial factors contributed to educational inequalities, partly via behavioural factors. Behavioural and psychosocial factors contributed only marginally to the explanation independent of material factors. Conclusion: Educational inequalities in mortality were explained by material, psychosocial, and behavioural factors. Material factors contributed most to the explanation, partly via psychosocial and behavioural factors. Improving the material situation of lower educated people may substantially reduce educational inequalities in mortality, partly via the psychosocial and behavioural consequences of improved material circumstances.

Anxiety and depression are risk factors rather than consequences of functional somatic symptoms in a general population of adolescents: The TRAILS study

BACKGROUND It is well known that functional somatic symptoms (FSS) are associated with anxiety and depression. However, evidence is lacking about how they are related to FSS. The aim of this study was to clarify these relationships and examine whether anxiety and depression are distinctly related to FSS. We hypothesized that anxiety contributes to the development of FSS and that depression is a consequence of FSS. METHODS FSS, anxiety, and depression were measured in adolescents (N = 2230, 51% women) by subscales of the Youth Self-Report during three assessment waves (adolescents successively aged: 10-12, 12-14, and 14-17) and by corresponding subscales of the Child Behavior Checklist. Using structural equation models, we combined trait and state models of FSS with those of anxiety and depression, respectively. We identified which relationships (contemporaneous and two-year lagged) significantly connected the states of FSS with the states of anxiety and depression. RESULTS Trait variables were all highly interrelated (r = .54-.63). Contrary to our hypothesis, both state anxiety (beta = .35) and state depression (beta = .45) had a strong contemporaneous effect on state FSS. In turn, state FSS had a weak two-year lagged effect on state anxiety (beta = .11) and an even weaker effect on state depression (beta = .06). CONCLUSIONS While the effect of anxiety and depression on FSS is strong and immediate, FSS exert a weaker and delayed influence on anxiety and depression. Further research should be done to detect the exact ways in which anxiety and depression lead to FSS, and FSS lead to anxiety and depression.

Validity and Reliability of the Strengths and Difficulties Questionnaire in 5–6 Year Olds: Differences by Gender or by Parental Education?

Introduction The Strengths and Difficulties Questionnaire (SDQ) is a relatively short instrument developed to detect psychosocial problems in children aged 3–16 years. It addresses four dimensions: emotional problems, conduct problems, hyperactivity/inattention problems, peer problems that count up to the total difficulties score, and a fifth dimension; prosocial behaviour. The validity and reliability of the SDQ has not been fully investigated in younger age groups. Therefore, this study assesses the validity and reliability of the parent and teacher versions of the SDQ in children aged 5–6 years in the total sample, and in subgroups according to child gender and parental education level. Methods The SDQ was administered as part of the Dutch regularly provided preventive health check for children aged 5–6 years. Parents provided information on 4750 children and teachers on 4516 children. Results Factor analyses of the parent and teacher SDQ confirmed that the original five scales were present (parent RMSEA = 0.05; teacher RMSEA = 0.07). Interrater correlations between parents and teachers were small (ICCs of 0.21–0.44) but comparable to what is generally found for psychosocial problem assessments in children. These correlations were larger for males than for females. Cronbach’s alphas for the total difficulties score were 0.77 for the parent SDQ and 0.81 for the teacher SDQ. Four of the subscales on the parent SDQ and two of the subscales on the teacher SDQ had an alpha <0.70. Alphas were generally higher for male children and for low parental education level. Discussion The validity and reliability of the total difficulties score of the parent and teacher SDQ are satisfactory in all groups by informant, child gender, and parental education level. Our results support the use of the SDQ in younger age groups. However, some subscales are less reliable and we recommend only to use the total difficulties score for screening purposes.

Comparison of the effects of low childhood socioeconomic position and low adulthood socioeconomic position on self rated health in four European studies

Background: Socioeconomic inequalities in health are a persistent feature throughout Europe. Researchers and policy makers are increasingly using a lifecourse perspective to explain these inequalities and direct policy. However, there are few, if any, cross national lifecourse comparisons in this area. Methods: Associations between socioeconomic position (SEP) in childhood and in adulthood and poor self rated health among men and women at midlife were tested in four European studies from England (n = 3615), France (n = 11 595), Germany (n = 4183), and the Netherlands (n = 3801). Results: For women, mutually adjusted analyses showed significant associations between poor self rated health and low SEP in both childhood and adulthood in England and the Netherlands, only low childhood SEP in Germany and neither childhood nor adulthood SEP in France. For men, mutually adjusted analyses showed significant associations between poor self rated health and low SEP in both childhood and adulthood in France and the Netherlands, only with adult SEP in England and only with childhood SEP in Germany. Conclusion: In most countries adult SEP showed stronger associations with self rated health than childhood SEP. There are both gender and national differences in the associations between childhood and adulthood SEP. Policies designed to reduce inequalities in health need to incorporate a lifecourse perspective that is sensitive to different national and gender issues. Ultimately, more cross national studies are required to better understand these processes.

Validation of the SDQ in a multi-ethnic population of young children

BACKGROUND The Strengths and Difficulties Questionnaire (SDQ) is a valuable screening tool for identifying psychosocial problems. Its performance in a multi-ethnic society, common to many paediatric health care workers, has not been investigated. Because it is important that screening instruments are valid and reliable for all ethnic groups within one society, we examined differences in the SDQs psychometric properties in a multi-ethnic society. METHODS The SDQ parent (n = 8114) and teacher form (n = 9355) were completed as part of a preventive health check for children aged 5-6 years of Dutch and non-Dutch ethnic backgrounds. The Child Behaviour Checklist (CBCL)/Teacher Report Form (TRF) was administered to a subsample. RESULTS Factor analysis of the parent-rated SDQ showed different rating patterns for two of the five subscales for non-Dutch children as compared with Dutch children. Cronbachs alpha for the total difficulties score varied by ethnic group (0.73-0.78 parent-rated SDQ, 0.80-0.83 teacher-rated SDQ), and coefficients were generally smaller for non-Dutch than for Dutch children (P < 0.05). Alpha coefficients for subscales varied between 0.31-0.85 for ethnic groups. Inter-rater correlations between parents and teachers for the total difficulties score varied between 0.20-0.41 between ethnic groups and were larger for Dutch than for non-Dutch children (P < 0.05). Concurrent validity was acceptable for most scales and most ethnic groups. CONCLUSION The total difficulties score of the parent- and teacher-rated SDQ is valid and reliable for different ethnic groups within Dutch society. However, there are differences in reliability and validity of the subscales, which makes interpretation of the subscales difficult for certain ethnic groups.

Does the Revised Child Anxiety and Depression Scale (RCADS) measure anxiety symptoms consistently across adolescence? The TRAILS study

We assessed if the Revised Child Anxiety and Depression Scale (RCADS) measures anxiety symptoms similarly across age groups within adolescence. This is crucial for valid comparison of anxiety levels between different age groups. Anxiety symptoms were assessed biennially in a representative population sample (n = 2226) at three time points (age range 10–17 years) using the RCADS anxiety subscales (generalized anxiety disorder [GAD], obsessive‐compulsive disorder [OCD], panic disorder [PD], separation anxiety [SA], social phobia [SP]). We examined longitudinal measurement invariance of the RCADS, using longitudinal confirmatory factor analysis, by examining the factor structure (configural invariance), factor loadings (metric invariance) and thresholds (strong invariance). We found that all anxiety subtypes were configural invariant. Metric invariance held for items on the GAD, OCD, PD and SA subscales; yet, for the SP subscale three items showed modest longitudinal variation at age 10–12. Model fit decreased modestly when enforcing additional constraints across time; however, model fit for these models was still adequate to excellent. We conclude that the RCADS measures anxiety symptoms similarly across time in a general population sample of adolescents; hence, measured changes in anxiety symptoms very likely reflect true changes in anxiety levels. We consider the instrument suitable to assess anxiety levels across adolescence. Copyright

National Origin and Behavioural Problems of Toddlers: The Role of Family Risk Factors and Maternal Immigration Characteristics

In many societies the prevalence of behavioural problems in school-aged children varies by national origin. We examined the association between national origin and behavioural problems in 1½-year-old children. Data on maternal national origin and the Child Behavior Checklist for toddlers (n = 4943) from a population-based cohort in the Netherlands were used. Children from various non-Dutch backgrounds all had a significantly higher mean behavioural problem score. After adjustment for family risk factors, like family income and maternal psychopathology, the differences attenuated, but remained statistically significant. Non-Dutch mothers with immigration risk factors, such as older age at immigration or no good Dutch language skills, reported significantly more behavioural problems in their offspring. In conclusion, the present study indicated more behavioural problems in immigrant toddlers from various backgrounds. Researchers and policymakers aiming to tackle disparities in behavioural problems should take into account that risks associated with national origin are intertwined with unfavourable family and immigration characteristics.

Adverse Life Events and Allele-Specific Methylation of the Serotonin Transporter Gene (SLC6A4) in Adolescents: The TRAILS Study

Objectives Adverse life events increase vulnerability to affective disorders later in life, possibly mediated by methylation of the serotonin transporter gene (SLC6A4). We investigated the relationship of SLC6A4 methylation with various types of adversity (perinatal adversity, traumatic youth experiences and stressful life events [SLEs]), as well as with the timing of SLEs (during childhood [0–11 years] or during adolescence [12–15 years]). In addition, we investigated whether different serotonin-transporter-linked polymorphic region genotypes were equally sensitive to SLE-related methylation. Methods In a population sample of 939 adolescents (mean age = 16.2 years), we assessed SLC6A4 methylation, SLC6A4 functionality (serotonin-transporter-linked polymorphic region “long” and “short” alleles, and rs25531), and adverse life events. Results Only a higher number of SLEs was positively associated with higher SLC6A4 methylation (B = 0.11, p = .011). Adolescent SLEs were associated with higher SLC6A4 methylation (B = 0.13, p = .004) independently of childhood SLEs (B = 0.02, p = .57). L-allele homozygotes showed a greater impact of SLEs on methylation (B = 0.37, p < .001) than did s-allele carriers (B = 0.04, p = .66), resulting in higher levels of SLC6A4 methylation for l-allele homozygotes among those experiencing high levels of SLEs. Conclusions Our findings demonstrate a higher level of SLC6A4 methylation after SLEs in adolescents, with a more pronounced association for SLEs during adolescence than during childhood. Considering the allele-specific sensitivity of SLC6A4 methylation to SLEs, this study may help clarify the role of SLC6A4 in the development of affective disorders.

Ethnic differences in problem perception and perceived need for care for young children with problem behaviour

BACKGROUND  Problem perception and perceived need for professional care are important determinants that can contribute to ethnic differences in the use of mental health care. Therefore, we studied ethnic differences in problem perception and perceived need for professional care in the parents and teachers of 5- to 6-year-old children from the general population who were selected for having emotional and behavioural problems. METHODS A cross-sectional study with data of 10,951 children from grade two of the elementary schools in the Rotterdam-Rijnmond area, The Netherlands. Parents and teachers completed the strengths and difficulties questionnaire (SDQ) as well as questions on problem perception and perceived need for care. The SDQ was used to identify children with emotional and behavioural problems. We included Dutch, Surinamese, Antillean, Moroccan and Turkish children in our sample with high (>P90) SDQ scores (N = 1,215), who were not currently receiving professional care for their problems. RESULTS Amongst children with high SDQ scores, problem perception was lower in non-Dutch parents than in Dutch parents (49% vs. 81%, p < 0.01). These lower rates of problem perception could not be explained by differences in socioeconomic position or severity of the problems. No ethnic differences were found in parental perceived need and in problem perception and perceived need reported by teachers. Higher levels of problem perception and perceived need were reported by teachers than by parents in all ethnic groups (PP: 87% vs. 63% and PN: 48% vs. 23%). CONCLUSIONS Child health professionals should be aware of ethnic variations in problem perception as low problem perception in parents of non-Dutch children may lead to miscommunication and unmet need for professional care for the child.

Glucocorticoid receptor gene methylation and HPA-axis regulation in adolescents. The TRAILS study.

Early life adversity and psychopathology are thought to be linked through HPA-axis deregulation. Changes in methylation levels of stress reactivity genes such as the glucocorticoid receptor gene (NR3C1) can be induced by adversity. Higher NR3C1 methylation levels have been associated with a reduced NR3C1 expression, possibly leading to impaired negative feedback regulation of the HPA-axis. In this study we tested whether methylation levels of NR3C1 were associated with HPA-axis regulation, operationalized as cortisol responses. In 361 adolescents (mean age 16.1, SD=0.6), salivary cortisol samples were collected before, during, and after a social stress task, from which response measures (cortisol activation and recovery) were calculated. Higher NR3C1 methylation levels were associated with a flattened cortisol recovery slope, indicating a delayed recovery time. Cortisol response activation was not associated with NR3C1 methylation. These results suggest that methylation of NR3C1 may impair negative feedback of the HPA-axis in adolescents.