Frank C. Verhulst

Bullying and victimization in elementary schools : A comparison of bullies, victims, bully/victims, and uninvolved preadolescents

Research on bullying and victimization largely rests on univariate analyses and on reports from a single informant. Researchers may thus know too little about the simultaneous effects of various independent and dependent variables, and their research may be biased by shared method variance. The database for this Dutch study was large (N = 1,065) and rich enough to allow multivariate analysis and multi-source information. In addition, the effect of familial vulnerability for internalizing and externalizing disorders was studied. Gender, aggressiveness, isolation, and dislikability were most strongly related to bullying and victimization. Among the many findings that deviated from or enhanced the univariate knowledge base were that not only victims and bully/victims but bullies as well were disliked and that parenting was unrelated to bullying and victimization once other factors were controlled.

The normative development of child and adolescent problem behavior.

The aim of this study was to identify normative developmental trajectories of parent-reported problems assessed with the Child Behavior Checklist (CBCL; T. M. Achenbach, 1991) in a representative sample of 2,076 children aged 4 to 18 years from the general population. The trajectories were determined by multilevel growth curve analyses on the CBCL syndromes in a Longitudinal multiple birth-cohort sample that was assessed 5 times with 2-year intervals. Most syndromes showed a linear increase or decrease with age or a curvilinear trajectory, except for thought problems. Trajectories for most syndromes differed for boys versus girls, except those for withdrawn, social problems, and thought problems. These normative developmental trajectories provide information against which developmental deviance in childhood and adolescence can be detected.

Evaluation of non-response bias in mental health determinants and outcomes in a large sample of pre-adolescents

Since non-response may jeopardize the validity of studies, comprehensive assessment of non-response is a prerequisite for proper interpretation of study findings. Recently, the baseline assessment of the TRacking Adolescents’ Individual Lives Survey (TRAILS), a prospective cohort study among Dutch pre-adolescents, was completed. The aim of this report is to examine non-response bias by comparing responders and non-responders regarding mental health determinants (e.g., demographics and cognitive performance) and outcomes, as well as associations between the two. Furthermore, we examine whether extended efforts to recruit participants contribute to the prevention or reduction of non-response bias. Thanks to various recruitment procedures, the initial response rate of 66% increased to a final rate of 76%. The extended efforts to recruit participants prevented non-response bias in the prevalence rates of psychopathology. Although non-responders differed from responders with respect to several individual characteristics, no significant differences were found regarding associations between these characteristics and psychopathology. We conclude that TRAILS provides a solid basis to improve our understanding of the development of mental health during adolescence.

Emotional and behavioral problems in children and adolescents with and without intellectual disability

BACKGROUND The main objective of this study was to assess and compare the prevalence of a wide range of emotional and behavioral problems in children with and without intellectual disability (ID). METHODS We studied 1,041 non-residential children randomly selected from special schools for educable (IQ 60 to 80) and trainable (IQ 30 to 60) children without severe additional physical or sensory impairments, and compared them to 1,855 children randomly selected from the general population (both ages 6 to 18). Parents completed the Child Behavior Checklist (CBCL), and teachers the Teachers Report Form (TRF). RESULTS Controlling for sex, age, and socioeconomic status, we found that both educable and trainable children had significantly higher mean scores on all CBCL and TRF scales than children without ID, except for trainable children on the scales Anxious/Depressed and Somatic Complaints. Almost 50% of children with ID had a Total Problem score in the deviant range compared to about 18% in children without ID. Compared to children without ID, the most prominent problem behaviors of educable children were Social Problems, Attention Problems, and Aggressive Behavior, and trainable children had an increased risk for Social Problems, Attention Problems, Withdrawn and Thought Problems. CONCLUSIONS Elevated scale scores reflected differences between children with and without ID over a broad range of items, and not solely on items more likely to be related to developmental delay. Therefore, problem areas covered by the items in these scales deserve special attention in the mental health care of children with ID.

Maternal Thyroid Function during Early Pregnancy and Cognitive Functioning in Early Childhood: The Generation R Study

CONTEXT Thyroid hormones are essential for neurodevelopment from early pregnancy onward. Yet population-based data on the association between maternal thyroid function in early pregnancy and childrens cognitive development are sparse. OBJECTIVE Our objective was to study associations of maternal hypothyroxinemia and of early pregnancy maternal TSH and free T(4)(FT(4)) levels across the entire range with cognitive functioning in early childhood. DESIGN AND SETTING We conducted a population-based cohort in The Netherlands. PARTICIPANTS Participants included 3659 children and their mothers. MAIN MEASURES In pregnant women with normal TSH levels at 13 wk gestation (SD = 1.7), mild and severe maternal hypothyroxinemia were defined as FT(4) concentrations below the 10th and 5th percentile, respectively. Childrens expressive vocabulary at 18 months was reported by mothers using the MacArthur Communicative Development Inventory. At 30 months, mothers completed the Language Development Survey and the Parent Report of Childrens Abilities measuring verbal and nonverbal cognitive functioning. RESULTS Maternal TSH was not related to the cognitive outcomes. An increase in maternal FT(4) predicted a lower risk of expressive language delay at 30 months only. However, both mild and severe maternal hypothyroxinemia was associated with a higher risk of expressive language delay across all ages [odds ratio (OR) = 1.44; 95% confidence interval (CI) = 1.09-1.91; P = 0.010 and OR = 1.80; 95% CI = 1.24-2.61; P = 0.002, respectively]. Severe maternal hypothyroxinemia also predicted a higher risk of nonverbal cognitive delay (OR = 2.03; 95% CI = 1.22-3.39; P = 0.007). CONCLUSIONS Maternal hypothyroxinemia is a risk factor for cognitive delay in early childhood.

Child and Adolescent Problems Predict DSM-IV Disorders in Adulthood: A 14-Year Follow-up of a Dutch Epidemiological Sample

OBJECTIVE Few studies exist that examine continuities between child and adult psychopathology in unselected samples. This study prospectively examined the adult outcomes of psychopathology in an epidemiological sample of children and adolescents across a 14-year period. METHOD In 1983, parent ratings of behavioral and emotional problems were obtained for 1,578 children and adolescents aged 4 through 16 years from the Dutch general population. At follow-up, 14 years later, subjects were reassessed with a standardized DSM-IV interview. RESULTS High levels of childhood problems predicted an approximate 2- to 6-fold increased risk for adulthood DSM-IV diagnoses. The associations between specific childhood problems and adulthood diagnoses were complex. Social Problems in girls predicted later DSM-IV disorder. Rule-breaking behavior in boys predicted both mood disorders and disruptive disorders in adulthood. CONCLUSIONS High levels of childhood behavioral and emotional problems are related to DSM-IV diagnoses in adulthood. The strongest predictor of disorders in adulthood was childhood rule-breaking behavior. Attention Problems did not predict any of the DSM-IV categories when adjusted for the associations with other Child Behavior Checklist scales.

Problem behavior in international adoptees. I: An epidemiological study

Behavioral/emotional problems and competencies in 2,148 international adoptees aged 10 to 15 years were compared with those in a same-aged sample of 933 children from the general population using the Achenbach Child Behavior Checklist. Parents reported more externalizing problem behavior for adopted than nonadopted children. More than twice as many 12- to 15-year-old adopted boys were scored above the cutoff criterion for problem behavior than nonadopted boys of the same age. For adopted boys in this age range especially high scores were obtained on the Delinquent and Hyperactive syndromes. Adopted children were scored less competent than nonadopted children in their social and academic functioning, whereas adopted children were found to be more active in nonsports activities and to function somewhat better than nonadopted children in sports and nonsports activities. In contrast to the effect of parental occupational level on competent scores for normative American and Dutch samples, adopted children from lower SES showed better academic performance, were less often referred to special classes, and had less other school problems than adopted children from higher SES.

Cohort Profile: The Dutch ‘TRacking Adolescents’ Individual Lives’ Survey’; TRAILS

Mental disorders account for one-fifth of the total burden of disease in the Western world, 1 and, as such, should require due attention from the international epidemiological research community. Good quality research on the aetiology and course of psychopathology in the population is impossible without reliable and valid data from long-term longitudinal cohort studies. Research on psychopathology in adolescence is important both from a scientific point of view and from the point of view of prevention and public health policy. Adolescence is characterized by major biological, psychological and social challenges and opportunities, where interaction between the individual and environment is intense, and developmental pathways are set in motion or become established. 2–4 Furthermore, adolescent psychopathology can have important consequences for education, relationships and socioeconomic achievement in later life. 5–7 These characteristics of adolescence do not only set high demands for cohort studies aiming to capture the most salient aspects of developmental pathways, they also ensure a great gain in empirical knowledge and an invaluable source of information for public health policy from such studies. In order to fully benefit from this potential, a multidisciplinary approach is essential.

The Generation R Study: Design and cohort profile

The Generation R Study is a population-based prospective cohort study from fetal life until young adulthood. The study is designed to identify early environmental and genetic causes of normal and abnormal growth, development and health from fetal life until young adulthood. The study focuses on four primary areas of research: (1) growth and physical development; (2) behavioral and cognitive development; (3) diseases in childhood; and (4) health and healthcare for pregnant women and children. In total, 9778 mothers with a delivery date from April 2002 until January 2006 were enrolled in the study. Of all eligible children at birth, 61% participate in the study. Data collection in the prenatal phase included physical examinations, questionnaires, fetal ultrasound examinations and biological samples. In addition, more detailed assessments are conducted in a subgroup of 1232 pregnant women and their children. The children form a prenatally recruited birth-cohort that will be followed until young adulthood. Eventually, results forthcoming from the Generation R Study have to contribute to the development of strategies for optimizing health and healthcare for pregnant women and children.

The Generation R Study Biobank: a resource for epidemiological studies in children and their parents

The Generation R Study is a population-based prospective cohort study from fetal life until young adulthood. The study is designed to identify early environmental and genetic causes of normal and abnormal growth, development and health from fetal life until young adulthood. In total, 9,778 mothers were enrolled in the study. Prenatal and postnatal data collection is conducted by physical examinations, questionnaires, interviews, ultrasound examinations and biological samples. Major efforts have been conducted for collecting biological specimens including DNA, blood for phenotypes and urine samples. In this paper, the collection, processing and storage of these biological specimens are described. Together with detailed phenotype measurements, these biological specimens form a unique resource for epidemiological studies focused on environmental exposures, genetic determinants and their interactions in relation to growth, health and development from fetal life onwards.