Influence of assessment instrument on ADHD diagnosis.

We compared four instruments commonly used to screen for and diagnose Attention-Deficit/Hyperactivity Disorder (ADHD) in children. The Bergen Child Study included a DSM-IV ADHD symptom list and the Strengths and Difficulties Questionnaire (SDQ) as screen in Phase one. Phase two included the parent Development and Well-Being Assessment (DAWBA), whereas Phase three comprised in-depth clinical assessment, including the Schedule for Affective Disorders and Schizophrenia for School Aged Children (K-SADS). We compared ADHD as diagnosed by the four instruments in the children with normal intellectual functioning participating in all three phases (N = 234). The DSM-IV ADHD symptom list showed moderate agreement with all other instruments (κ = 0.53-0.57), whereas there was fair agreement between the K-SADS-DAWBA (κ = 0.31) and between SDQ-DAWBA (κ = 0.33). The DAWBA diagnosed fewer children with ADHD than did the other instruments. Implications for use of the instruments are discussed.

Becoming Dad: Expectant Fathers' Attachment Style and Prenatal Representations of the Unborn Child.

How expectant fathers think and feel about the unborn child (prenatal representations), has shown associations with fathers' postnatal parenting behaviors, observed father-infant interactional quality and child cognitive development. There is limited knowledge about fathers' prenatal representations. The present study examined if fathers' partner-related attachment styles were related to their prenatal representations of the unborn child. In the "Little in Norway Study", an ongoing prospective, longitudinal population-based study, 396 expectant fathers completed the Experiences in Close Relationships Scale at enrollment (mean gestational week = 23.76, SD = 4.93), and in gestational weeks 27-35 completed three questions assessing prenatal representations. Correlations of attachment style and prenatal representations were reported using logistic regression analyses. We found that an avoidant attachment style by fathers were predicted to have absent or negative representations on all three items (1) "strongest feeling about the unborn child" (Cl = 1.19-2.73), (2) "thoughts about child personality" (Cl = 1.16-1.87), and (3) "experiences of relationship with the child" (Cl = 1.14-1.75). Father anxious attachment style was not significantly associated with absent or negative prenatal representations. Results suggest that expectant fathers with a partner related avoidant attachment style have an increased risk of having absent or negative prenatal representations of the unborn child.

The factor structure of ADHD in a general population of primary school children.

OBJECTIVE: To examine whether a bifactor model with a general ADHD factor and domain specific factors of inattention, hyperactivity and impulsivity was supported in a large general population sample of children. We also explored the utility of forming subscales based on the domain-specific factors. METHODS: Child mental health questionnaires were completed by both teachers and parents of all children in grades 2-4 in Bergen, Norway. Confirmatory factor analysis was performed on the ADHD items of a modified version of the Swanson, Nolan and Pelham Questionnaire-IV (SNAP-IV) for 6,237 children. RESULTS: The bifactor model showed very good model fit with a strong general ADHD factor and specific factors for impulsivity and inattention. The subfactors, especially hyperactivity, generated from the SNAP-IV ADHD items conveyed little unique variance in the model. CONCLUSIONS: The findings in this general population sample with a strong general ADHD factor in the bifactor model supports the view on ADHD as a unitary concept with specific domain factors for inattention and impulsivity, but not for hyperactivity. The bifactor model questions the utility of constructing ADHD subscales by the use of a simple sum score when using the SNAP-IV.

Prevalence of the ADHD phenotype in 7- to 9-year-old children: effects of informant, gender and non-participation.

PURPOSE: To estimate the prevalence of the ADHD phenotype based on parent and teacher reports in a general population sample of 7- to 9-year-old Norwegian children and evaluate the effect of parent attrition, gender and informant on the prevalence estimate. METHODS: The population consisted of all children (N = 9,430) attending 2nd-4th grade in the City of Bergen, Norway. The 18 symptoms of ADHD corresponding to the SNAP-IV and DSM-IV were included in the Bergen Child Study questionnaire to teachers and parents. Teacher information was available for 9,137 children (97%) and information from both informants was available for the 6,237 children (66%) whose parents agreed to participate in the study. RESULTS: The prevalence of the ADHD phenotype based on the combination of parent and teacher reports was 5.2% among participants. Teacher ratings of non-participants had a doubled rate of ADHD high scorers with an OR of 2.1 (95% CI, 1.9-2.4). The non-participant ADHD high scorers had more inattentive and fewer hyperactive/impulsive symptoms as compared to participating ADHD high scorers. Teachers reported high scores of hyperactivity/impulsivity and the combined symptom constellation much more frequently in boys than girls, while the difference between genders was less marked according to parent reports. CONCLUSIONS: The ADHD phenotype was twice as prevalent among non-participants as among participants. Reported prevalences in population studies are therefore likely to be underestimates, if such attrition bias is not accounted for. Choice of informant, criteria for symptom count, definitions of subtypes and gender differences influence the prevalence estimates of the ADHD phenotype.

Screening for the attention deficit hyperactivity disorder phenotype using the strength and difficulties questionnaire.

The strengths and difficulties questionnaire (SDQ) is a broad-band child mental health instrument, which has been reported to be a good screener for the ADHD phenotype. Questionnaires containing the SDQ and the 18 SNAP-IV items corresponding to the DSM-IV ADHD symptoms were completed by parents and teachers for 66% (N = 6,233) of all 7- to 9-year-olds in the city of Bergen, Norway, 2002. Screening properties of the five-item SDQ hyperactivity-inattention subscale for the DSM-IV ADHD phenotype were examined. Using the DSM-IV ADHD phenotype based on both informants as the gold standard (5.2% of the sample), the receiver operating characteristics (ROC) analyses demonstrated an area under the curve of 0.91 (95% CI: 0.90-0.92) for parent and 0.95 (95% CI: 0.94-0.95) for teacher SDQ hyperactivity-inattention subscale ratings. The SDQ hyperactivity-inattention predictive algorithm identified 74% of those with the ADHD combined subtype as possible or probable cases, but only 22% of those with the inattentive subtype. The 5-item long SDQ hyperactivity-inattention subscale is a shorter substitute for the 18-item ADHD symptom list. The SDQ predictive algorithm had an acceptable sensitivity for the ADHD combined subtype, but low sensitivity for the ADHD inattentive and the ADHD hyperactive subtypes.

Teacher reports of hypoactivity symptoms reflect slow cognitive processing speed in primary school children.

The mediating effect of cognitive processing speed on the ability of a primary school child to achieve his/her full potential of intellectual functioning emphasizes the importance of methods to detect "slow" children. Primary school teachers may be the first to have concerns about inattentive pupils who show symptoms of hypoactivity, but may find the symptoms difficult to interpret. In the present study we ask if a primary school teacher's report of hypoactivity symptoms can be explained by the child's performance on tests of processing speed. The 255 children included in the present study were part of the first wave of the Bergen Child Study, in which teachers completed a questionnaire including two hypoactivity items from the Five to Fifteen (FTF) questionnaire. Processing speed was measured by the Processing Speed Index (PSI) from the WISC-III, 1-2 years after the teacher rating. Teachers reported "certainly true" on at least one FTF item of hypoactivity for 11.8% of the children. These children obtained lower scores on the PSI than the remaining children in the sample. The PSI accounted for a considerable proportion of the variance of teacher reports on the FTF item "difficulty getting started on a task/activity". The risk of a PSI score below 85 was increased in children with teacher-reported hypoactivity symptoms. The results indicate that teacher reports of hypoactivity symptoms reflect slow cognitive processing speed and should be followed up by a psychometric examination. Still, future studies are needed to improve detection and treatment of children with slow processing speed.