Validity and reliability of the short Test Anxiety Inventory (TAI-5) in Dutch adolescents.

The present study examined the psychometric properties of the short Test Anxiety Inventory (TAI-5) in a Dutch adolescent sample. The sample consisted of 2063 secondary school students (mean age 13.6 years, 48% girls) who filled out a battery of screening questionnaires for a routine health check. We investigated structural validity with a confirmatory factor analysis, scale reliability with internal consistency coefficients, and construct validity with hypotheses testing and convergent validity. The proposed one-factor structure fitted well in the present sample. However, there was an indication of measurement variance for gender. Scale reliability was high (ω = 0.88), and sufficient positive correlations were found between TAI-5 scores and anxiety, depression, worry, executive functioning, and sleep problems (r ranging from 0.36 to 0.56). Girls had significantly higher test anxiety scores than boys (d = 0.47). The present study provided evidence for the validity and reliability of TAI-5 scores in a general population of Dutch adolescents.

Differences in Anxiety and Depression Among Migrant and Non-Migrant Primary School Children in The Netherlands.

This is the first Dutch study investigating symptoms of five DSM-IV-classified anxiety disorders and depression in a large sample of pre-adolescent children with and without a migration background, adjusting for socioeconomic position (SEP) and social preference. Both are potential explanatory factors for differences in mental health among migrant children. We measured anxiety and depression scores with the self-report Revised Child Anxiety and Depression Scale (RCADS) in 2063 children (aged 8-13 years, 55% girls) in the Netherlands. Surinamese/Antillean, Turkish, and Moroccan children reported significantly higher anxiety scores than Dutch children. SEP and peer rejection partly explained higher anxiety scores. Surinamese/Antillean and Turkish children reported comparable depression scores to Dutch children, but Moroccan children reported lower depression scores after adjusting for SEP and peer rejection. Girls reported higher anxiety and depression levels across all four subgroups. Although differences between children with or without a migration background were small, these may increase in later life as the prevalence of anxiety and depression increases with age.

Exploring the Association of Age with Depressive Symptomatology in Childhood and Adolescence: A Network Study.

OBJECTIVE: This study aimed to explore the association of age with individual depression and anxiety symptoms and their connectivity (i.e., number/strength of connections with other symptoms) in girls and boys. METHOD: Our study comprised cross-sectional data from 31,960 Dutch girls and 32,162 Dutch boys aged 8 to 18 and considered 11 depression symptoms and 14 anxiety symptoms measured by the Revised Child Anxiety and Depression Scale. Network estimations were used to examine whether age was associated with individual symptoms and, in a separate step, with the connectivity of depression symptoms with other depression symptoms and with the connectivity of depression symptoms with anxiety symptoms. RESULTS: Age was, in general, positively associated with depression symptoms in girls, but not in boys, and with the connectivity of depression symptoms with other depression symptoms in both sexes. These findings were the most profound for energy-related symptoms in girls. Age was, in general, negatively associated with anxiety symptoms and not or negatively associated with the connectivity of depression symptoms with anxiety symptoms in girls and boys, respectively. Substantial differences across symptoms were found. CONCLUSIONS: This study shows that it is important to focus on individual symptoms, for age is mainly associated with energy-related depression symptoms and their connectivity in girls. Future etiologic studies may examine the role of energy-related depression symptoms in the development of depressive symptomatology in girls as these symptoms seem potential targets for the prevention of depression in the female population.

Associations between overweight and mental health problems among adolescents, and the mediating role of victimization.

BACKGROUND: Evidence has not been conclusive on whether adolescent overweight is associated with mental health, possibly caused by indirect, yet untested associations. Therefore, the purpose of this study was to examine the association between overweight or obesity and mental health problems among adolescents, and to determine whether victimization plays a mediating role in these associations. METHODS: Self-reported data on mental health and victimization and objectively measured Body Mass Index data were used, using three cohorts (2010-2011 until 2012-2013) and an interval between the measurement waves of two years later. We performed a multi-level mediation analysis with a two-level structure to incorporate the clustering of the measurements within individuals. The study population consisted of 13,740 secondary school students, 13-14 years old at the first measurement moment, in Amsterdam, the Netherlands. RESULTS: Compared to their normal-weight peers, adolescents with overweight or obesity reported psychosocial problems and suicidal thoughts more often. Victimization was a significant mediator in the relationship between having overweight, and psychosocial problems (indirect effect OR: 2.3; 95% CI 1.5, 3.7 and direct effect OR: 1.4; 95% CI 1.2, 1.7) or suicidal thoughts (indirect effect OR: 2.1; 95% CI 1.4, 3.2 and direct effect OR: 1.3; 95% CI 1.1, 1.5). The associations between obesity, and psychosocial problems (indirect OR: 6.2; 95% CI 2.8, 14.7 and direct effect OR: 1.4; 95% CI 1.0, 2.0), or suicidal thoughts (indirect OR: 4.5; 95% CI 2.3, 9.1 and direct effect OR: 1.5; 95% CI 1.1, 2.0) were even stronger. CONCLUSIONS: Overweight and obesity were significantly associated with mental health problems in adolescents, and victimization played a mediating role in this association. Victimization and mental health should be integrated into prevention programs that address healthy weight development. Moreover, overweight should be given more attention in programs to prevent victimization and promote adolescent mental health.

Sociodemographic differences in 10-year time trends of emotional and behavioural problems among adolescents attending secondary schools in Amsterdam, The Netherlands.

Societal change in western societies may impact emotional and behavioural problems of adolescents. Firm epidemiological evidence of changes in emotional and behavioural problems during the last decade is lacking. Insight into secular changes in emotional and behavioural problems among adolescents from various sociodemographic groups is crucial for adequate and targeted policy making. Therefore, the purpose of this study was to examine 10-year time trends in emotional and behavioural problems among adolescents, and potential differences in time trends between sociodemographic groups. Analyses were based on annually repeated cross-sectional data including 56,159 multi-ethnic students (13-14 years old) in the second year of various levels of secondary education in Amsterdam, The Netherlands, using the internationally validated Strengths and Difficulties Questionnaire. In general, emotional and behavioural problems increased over a 10-year time period (i.e., relative increase of total difficulties by 19%). This increase was mainly due to an increase in hyperactivity/inattention problems, while peer-relationship problems decreased. Time trends differed somewhat by sex: total difficulties and emotional problems increased in girls but remained fairly stable in boys. In Amsterdam, emotional and behavioural problems in adolescents seemingly increased over time, especially hyperactivity/inattention problems. Further research is needed to clarify the underlying causes. We cannot totally exclude potential confounders underlying our findings. Our findings can inform policies to target health programs at sociodemographic groups at increased risk.

A longitudinal study on determinants of HPV vaccination uptake in parents/guardians from different ethnic backgrounds in Amsterdam, the Netherlands.

BACKGROUND: Human papillomavirus (HPV) vaccination coverage in the Netherlands is low (~60%) compared to other childhood vaccinations (>90%), and even lower among ethnic minorities. The aim of this study was to explore the possible impact of ethnicity on the determinants of both HPV vaccination intention and HPV vaccination uptake among parents/guardians having a daughter that is invited for the HPV vaccination. METHODS: In February 2014, parents/guardians living in Amsterdam were invited to complete a questionnaire about social-psychological determinants of their decision making process regarding the HPV vaccination of their daughter and socio-demographic characteristics. This questionnaire was sent approximately one month before the daughter was scheduled to receive her first HPV vaccine dose. Their daughters' HPV vaccination status was retrieved from the national vaccination database. We distinguished four ethnic groups: Dutch (NL), Surinamese, Netherlands Antillean, and Aruban (SNA), Middle-Eastern and North-African (MENA), and Other. To assess the impact of determinants on both intention and uptake, linear and logistic regression analyses were used respectively. Missing data were imputed using multiple imputation by chained equation. RESULTS: In total 1,309 parents/guardians participated (33% participation rate). In all groups we found the mothers' intention to be the strongest predictor of their daughters' HPV vaccination uptake. Explained variance of uptake was highest in the NL-group (pseudo-R2:0.56) and lower in the other ethnic groups (pseudo-R2 varied between 0.23 and 0.29). The lower explained variance can be attributed to the relative large proportion of participants with a positive intention that finally did not go for vaccination in the SNA-group (11%) and MENA-group (30%). Explained variance (R2) of intention varied between 0.66 and 0.77 across ethnic groups, and was best explained by the proximal social-psychological determinants. The strength of association of these determinants with both intention and uptake were largely similar across ethnic groups. CONCLUSION: We conclude that the same determinants should be targeted in the different ethnic groups, although the mode of delivery of the intervention needs to be tailored to the different cultural backgrounds. Further research is needed to explain the observed discrepancy between intention and uptake, especially among parents/guardians in the non-Dutch groups.

Sustainability of the good behaviour game in Dutch primary schools.

Summary: Sustainability of health promotion programs is essential to maintain their positive effects. However, few studies have examined the extent of program sustainability and the factors influencing it. We examined these issues through the Good Behaviour Game (GBG), a classroom-based program in primary schools with beneficial behavioural and health-related effects that was implemented in 2008. GBG coordinators of 17 participating schools were invited in the study 2 years after the initial program implementation. Sustainability was measured using a 20-item checklist comprised of four dimensions of routinization including: memory, adaptation, values and rules. A semi-structured interview was then completed with 16 of the GBG coordinators to discuss the checklist scores and to probe in more depth the current level of sustainability. Based on the checklist scores, sustainability of the GBG was considered 'high' in five schools, 'medium' in another five and 'weak' in six. Factors influencing sustainability identified by GBG coordinators were organizational strength, strong leadership, program championship and the perceived modifiability and effectiveness of the GBG. Also, different factors were related to different dimensions of routinization. The combination of a sustainability checklist and an interview about influential factors may help to further clarify the sustainability construct and reveal which implementation sites, routinization dimensions and influential factors should be explored to further facilitate the sustaining of programs with proven effectiveness.

[Thinness and overweight in children from Amsterdam: a trend analysis and forecast]. / Onder- en overgewicht bij Amsterdamse kinderen: een trendanalyse en prognose.

OBJECTIVE: To determine the trends in prevalence of moderate and severe thinness, overweight and obesity in children living in Amsterdam between 2009 and 2013 and estimate prevalences for 2020. DESIGN: Historical cohort study. METHOD: 158,730 measurements of height and weight of 112,405 children from Amsterdam were analysed. Moderate thinness, severe thinness, overweight and obesity were determined using international BMI cut-off values. Trends were analysed using Generalized Estimating Equations (GEE) for two age groups: pre-schoolers (2 and 3 years) and school-aged children (5, 10 and 14 years). The 'self-projecting method,' which allowed us to extend former trends into the future, was used to estimate prevalences for 2020. RESULTS: The prevalence of moderate thinness increased significantly in both age groups. The prevalence of severe thinness did not change. The prevalences of overweight and obesity declined significantly in both age groups. These trends were most evident in children of Dutch origin. Other ethnic groups also showed declining prevalences but not in both age groups or both categories of overweight. The prognosis for 2020 shows a further decline in the prevalence of overweight and obesity and an increase in the prevalence of thinness. CONCLUSION: A decline in the prevalences of overweight and obesity was observed in Amsterdam children, including children of Turkish and Moroccan origin. The prevalence rates are still high, so investing in prevention remains necessary. The prevalence of moderate thinness also seems to be increasing. Continued monitoring of children in all BMI classes is therefore important.

Indicated Prevention of Childhood Anxiety and Depression: Results From a Practice-Based Study up to 12 Months After Intervention.

OBJECTIVES: We investigated whether intervention effects of FRIENDS for Life, a school-based prevention program for children with anxiety or depression symptoms, were maintained over a period of 12 months after the intervention in a naturalistic setting. METHODS: We used a quasi-experimental design, with 339 children in the intervention group and 157 in the control group (aged 8-13 years) in schools in Amsterdam, the Netherlands. We collected self-, teacher, and peer reports of anxiety and depression scores before and after intervention, and 6 and 12 months after intervention, from 2010 to 2012. RESULTS: Intervention-group children reported a continuing and significant decrease in anxiety and depression scores compared with the control group. Twelve months after the intervention, participants' anxiety and depression levels were comparable to those of the general population. Girls reported a stronger decrease in anxiety scores than did boys. Teacher reports suggested no effects. Although classmates reported increased internalizing problems in intervention-group children immediately after intervention, these effects disappeared over time. CONCLUSIONS: FRIENDS for Life, an indicated prevention program, yielded long-lasting and continuing reduction in anxiety and depression problems when implemented in daily school practice.

Structure, reliability, and validity of the revised child anxiety and depression scale (RCADS) in a multi-ethnic urban sample of Dutch children.

BACKGROUND: Although anxiety and, to a lesser extent, depression are highly prevalent in children, these problems are, difficult to identify. The Revised Anxiety and Depression Scale (RCADS) assesses self-reported symptoms of anxiety and depression in youth. METHODS: The present study examined the factor structure, internal consistency, short-term stability, and validity including sensitivity to change of the RCADS in a multi-ethnic urban sample of 3636 Dutch children aged 8 to 13 years old. RESULTS: Results indicate that the RCADS is a reliable and valid instrument. The original 6-factor structure was replicated to a fair extent in the present study (RMSEA = 0.048) and internal consistency was good (αs = 0.70-0.96). ICCs for short-term stability were 0.76 to 0.86. Girls and children who indicated wishing to participate in a program targeting anxiety and depression had higher RCADS scores. Sensitivity to change analyses showed that the RCADS can detect changes in anxiety and depression symptoms in children who participated in a preventive intervention. The study showed low agreement between teacher and self-reported internalizing problems, even for children scoring above the 90(th) percentile of the RCADS, indicating a high level of problems, emphasizing the need to also take child reports into account when screening for anxiety and depression in children. CONCLUSION: This study shows that the RCADS can yield reliable data on a diversity of anxiety disorders and depression in urban children aged 8-13 from very diverse ethnic backgrounds. TRIAL REGISTRATION: Netherlands Trial Register: NTR2397 . Registered 30 June 2010.

Neighborhood socioeconomic deprivation characteristics in child (0-18 years) health studies: a review.

BACKGROUND: Growing up in socioeconomically deprived neighborhoods has been shown to have negative health effects on children. However, the most recent review on which measures are used to investigate the association between neighborhood characteristics and child (0-18 year) health included studies only until 2004. Insight into more recent research is needed for the further development of these measures. OBJECTIVES: To review neighborhood socioeconomic deprivation characteristics used in recent studies investigating the relationship between neighborhood socioeconomic deprivation and child health. METHODS: Sensitive search in MEDLINE, Embase, PsycINFO, Sociological Abstracts databases (2004-2013). RESULTS: Ultimately, 19 studies were included. We found ten neighborhood socioeconomic deprivation constructs, of which income/wealth, employment, and education were most frequently used. The choice for neighborhood characteristics seemed independent of the health outcome and in most cases was not based on a specific theoretical background or earlier work. CONCLUSION: Studies vary regarding study designs, measures and outcomes. Researchers should clearly specify their choice of neighborhood socioeconomic deprivation characteristics; preferably, these should be theory-based and used consistently.

A mixed methods process evaluation of the implementation of JUMP-in, a multilevel school-based intervention aimed at physical activity promotion.

BACKGROUND: The aim of the present study was to investigate factors influencing the adoption, implementation, and institutionalization process of JUMP-in-a multilevel school-based physical activity promotion program-to optimize the dissemination of the intervention and improve its effectiveness. The process evaluation concerned the constraints and success and failure factors at sociopolitical, organizational, user, and intervention levels. METHODS: A mixed methods approach including qualitative and quantitative data was conducted during two school years (2006-2008). RESULTS: JUMP-in was successfully embedded in the Amsterdam municipal policy and in the organizational structure and daily practices of the sectors involved. A general impeding factor was the complexity of the multilevel programme requiring multidisciplinary collaboration between organizations. In addition, there was a discrepancy between the recommendation to standardize and simplify the innovation and the need to tailor the strategies to local environmental, social, and cultural aspects. CONCLUSIONS: This process evaluation provides challenges and remedies for managing discrepancies between prerequisites for an effective innovation and demands of daily implementation practice. The main recommendations are (a) standardized, simplified guidelines; (b) stepwise implementation; (c) formalized coalitions, integration of policy, and synchronization of tasks and protocols; and (d) smart planning and control by clear communication and feedback instruments. If these recommendations are incorporated into the JUMP-in intervention and organization, increased effectiveness and long-term effects can be expected.

Mediators of the effect of the JUMP-in intervention on physical activity and sedentary behavior in Dutch primary schoolchildren from disadvantaged neighborhoods.

BACKGROUND: Important health benefits can be achieved when physical activity in children from low socio-economic status is promoted and sedentariness is limited. By specifying the mediating mechanisms of existing interventions one can improve future physical activity interventions. This study explored potential mediators of the long-term effect of the school-based multicomponent JUMP-in intervention on sport participation, outdoor play and screen time in Dutch primary schoolchildren from disadvantaged neighborhoods. METHODS: In total, 600 primary schoolchildren (aged 9.8 ± 0.7, 51% girls, 13% Dutch ethnicity, 35% overweight) from 9 intervention and 10 control schools were included in the analyses. JUMP-in was developed using Intervention Mapping, and targeted psychological and environmental determinants of physical activity. Outcome behaviors were self-reported sport participation, outdoor play, TV-viewing behavior and computer use. Potential mediators were self-reported psychological, social and physical environmental factors. RESULTS: JUMP-in was effective in improving sport participation after 20 months, but not in improving outdoor play, or reducing TV-viewing or computer time. JUMP-in was not effective in changing hypothesized mediators so no significant mediated effects could be identified. However, changes in self-efficacy, social support and habit strength were positively associated with changes in sport participation, and changes in social support, self-efficacy, perceived planning skills, enjoyment and habit strength were positively associated with changes in outdoor play. Changes in enjoyment was positively associated with changes in TV-viewing while parental rules were negatively associated. Having a computer in the bedroom and enjoyment were positively associated with changes in computer use, while changes in parental rules were negatively associated. CONCLUSIONS: Besides a significant positive effect on sports participation, no significant intervention effect on outdoor play, screen time or any of the potential mediators was found. This suggest that other (unmeasured) factors operated as mediating mechanisms of the intervention, that we used unsuccessful intervention strategies, that the strategies were inappropriately implemented, or that children are unable to accurately recall past activities and cognitions. Additionally, the school setting might not be the sole channel to influence leisure time activities. Still, several personal and environmental constructs were found to be relevant in predicting change in sport participation, outdoor play and screen behavior and seem to be potential mediators. Future interventions are recommended including more effective strategies targeting these relevant constructs, addressing different constructs (e.g. pedagogic skills of parents), and focusing on different implementation settings. TRIAL REGISTRATION: [corrected] ISRCTN17489378.

Caffeine intake during pregnancy and risk of problem behavior in 5- to 6-year-old children.

BACKGROUND AND OBJECTIVE: Human studies that have investigated the association between caffeine intake during pregnancy and offspring's behavioral outcomes are scant and inconclusive. We prospectively investigated the association between maternal caffeine intake during pregnancy and children's problem behavior at age 5 to 6 years. Mediation by fetal growth restriction and gestational age as well as effect modification by the child's gender and maternal smoking was tested. METHODS: In a community based multiethnic birth cohort, dietary caffeine intake (coffee, caffeinated tea, and cola) was measured (maternal self-report, n = 8202) around the 16th week of gestation. At age 5, children's overall problem behavior, emotional problems, conduct problems, hyperactivity/inattention problems, peer relationship problems, and prosocial behavior were rated by both mother and teacher (n = 3439) with the Strengths and Difficulties Questionnaire. Analyses were adjusted for maternal age, ethnicity, cohabitant status, education, smoking and alcohol consumption during pregnancy, child's gender, family size, and prenatal maternal anxiety. RESULTS: Caffeine intake was not associated with a higher risk for behavior problems or with suboptimal prosocial behavior. No evidence was found for mediation by fetal growth restriction or gestational age, nor for effect modification by the child's gender. CONCLUSIONS: Results did not provide evidence for developmental programming influences of intrauterine exposure to caffeine on offspring's problem behavior at age 5. Present results give no indication to advise pregnant women to reduce their caffeine intake to prevent behavior problems in their children.

Study design of 'FRIENDS for Life': process and effect evaluation of an indicated school-based prevention programme for childhood anxiety and depression.

BACKGROUND: Anxiety disorders and depression are highly prevalent in children and affect their current and future functioning. 'FRIENDS for Life' is a cognitive-behavioural programme teaching children skills to cope more effectively with feelings of anxiety and depression. Although 'FRIENDS for Life' is increasingly being implemented at Dutch schools, its effectiveness as a preventive intervention in Dutch schools has never been investigated. The aim of the study is to evaluate the effectiveness of 'FRIENDS for Life' as an indicated school-based prevention programme for children with early or mild signs of anxiety or depression. METHODS/DESIGN: This study is a controlled trial with one pre-intervention and three post-intervention measurements (directly after, and 6 and 12 months after the end of the programme). The study sample consists of children aged 10-12 years (grades 6, 7 and 8 of Dutch primary schools), who show symptoms of anxiety or depressive disorder. Data are collected through self-report, teacher report and peer nomination. A process evaluation is conducted to investigate programme integrity (whether the programme has been executed according to protocol) and to evaluate children's and parents' opinions about 'FRIENDS for Life' using online focus groups and interviews. DISCUSSION: The present study will provide insight into the effectiveness of 'FRIENDS for Life' as an indicated school-based prevention programme for children with early or mild signs of anxiety or depression. TRIAL REGISTRATION: Netherlands Trial Register (NTR): NTR2397.

The effectiveness of a perinatal education programme on smoking, infant care, and psychosocial health for ethnic Turkish women.

OBJECTIVE: antenatal programmes might be effective in preventing unhealthy lifestyles, poor maternal infant care practices, and poor psychosocial health in ethnic minority women, but there are few evidence-based interventions. For this reason an antenatal education programme, called 'Happy Mothers, Happy Babies' (HMHB) was systematically designed for ethnic Turkish women in the Netherlands. DESIGN: in a non-randomised trial Turkish women attending HMHB (HMHB group) were compared with those receiving care as usual (control group). SETTING: Parent-Child Centres, which provide integrated maternity and infant care. PARTICIPANTS: in both the HMHB (n=119) and the control (n=120) group, questionnaires were administered by ethnic Turkish interviewers at three (T0) and eight (T1) months of pregnancy, and two (T2) and six (T3) months after birth. FINDINGS: at baseline, women in the HMHB group had significantly lower educational levels, were less frequently in paid employment, had less knowledge about smoking, and showed more often mildly depressive symptoms. Adjusted analyses showed that HMHB was effective in improving knowledge about smoking (OR=2.73; 95% CI 1.40, 5.31), intention to engage in prevention of sudden infant death syndrome (SIDS) (OR=8.08; 95% CI 3.34, 19.56) and short-term SIDS prevention behaviour (OR=2.22; 95% CI=1.18, 4.19). However, no intervention effect was found for smoking during pregnancy, SIDS prevention behaviour on the long term, soothing behaviour, serious depressive symptoms, and parent-child attachment. KEY CONCLUSIONS: although we could not demonstrate intervention effects on all outcome measures, the HMHB programme appears to be highly welcome, and reaches an underserved minority group at increased risk for adverse perinatal outcomes. IMPLICATIONS FOR PRACTICE: the HMHB programme is one of the first systematically developed antenatal interventions for ethnic minority women. The programme can be used as a basic antenatal programme, and as a screening opportunity for women who smoke or show serious depressive symptoms.

Maternal vitamin B-12 and folate status during pregnancy and excessive infant crying.

BACKGROUND: The etiology of excessive infant crying is largely unknown. We hypothesize that excessive infant crying may have an early nutritional origin during fetal development. AIMS: This study is the first to explore whether (1) maternal vitamin B-12 and folate status during pregnancy are associated with excessive infant crying, and (2) whether and how maternal psychological well-being during pregnancy affects these associations. STUDY DESIGN: Women were approached around the 12th pregnancy week to complete a questionnaire (n=8266) and to donate a blood sample (n=4389); vitamin B-12 and folate concentrations were determined in serum. Infant crying behavior was measured through a postpartum questionnaire (±3 months; n=5218). SUBJECTS: Pregnant women living in Amsterdam and their newborn child. OUTCOME MEASURES: Excessive infant crying, defined as crying ≥3 h/day on average in the past week. RESULTS: Multiple logistic regression analysis was performed for 2921 (vitamin B-12) and 2622 (folate) women.Vitamin B-12 concentration (categorized into quintiles) was associated with excessive infant crying after adjustment for maternal age, parity, ethnicity, education, maternal smoking and psychological problems (OR[95%CI]: Q1=3.31[1.48-7.41]; Q2=2.50[1.08-5.77]; Q3=2.59[1.12-6.00]; Q4=2.77[1.20-6.40]; Q5=reference). Stratified analysis suggested a stronger association among women with high levels of psychological problems during pregnancy. Folate concentration was not associated with excessive infant crying. CONCLUSIONS: First evidence is provided for an early nutritional origin in excessive infant crying. A low maternal vitamin B-12 status during pregnancy could, in theory, affect infant crying behavior through two potential mechanisms: the methionine-homocysteine metabolism and/or the maturation of the sleep-wake rhythm.