Peik Gustafsson

Associations between cerebral blood-flow measured by single photon emission computed tomography (SPECT), electro-encephalogram (EEG), behaviour symptoms, cognition and neurological soft signs in children with attention-deficit hyperactivity disorder (ADHD).

Twenty‐eight children with attention‐deficit hyperactivity disorder (ADHD) were examined with SPECT (single photon emission computed tomography). Seven of the children had abnormal distribution of the regional cerebral blood‐flow (rCBF) on visual evaluation and 10 had abnormal EEG findings. The only clinical finding that differentiated the group with normal from abnormal rCBF was behaviour symptom load. A factor analysis of the rCBF in different regions of interest yielded one factor with low rCBF in the temporal and cerebellar regions and high rCBF in the subcortical and thalamic regions, which was significantly associated with the degree of motor impairment and results on a cognitive test (WISC). Another factor consisting of high rCBF in frontal and parietal regions had a significant negative correlation with the degree of behaviour symptoms. There was a negative correlation between the rCBF in the right frontal regions and the degree of behaviour symptoms. The number of minor physical anomalies (MPA) was negatively correlated to the rCBF in the frontal lobes bilaterally.

Perinatal, maternal, and fetal characteristics of children diagnosed with attention-deficit-hyperactivity disorder: results from a population-based study utilizing the Swedish Medical Birth Register.

Aim  The aim of this study was to evaluate the impact of pre‐ and perinatal factors on the risk of developing attention‐deficit–hyperactivity disorder (ADHD).

Fetal exposure to perfluorinated compounds and attention deficit hyperactivity disorder in childhood.

Background The association between exposure to perfluorinated compounds (PFCs) and attention deficit hyperactivity disorder (ADHD) diagnosis has been sparsely investigated in humans and the findings are inconsistent. Objectives A matched case-control study was conducted to investigate the association between fetal exposure to PFCs and ADHD diagnosis in childhood. Methods The study base comprised children born in Malmö, Sweden, between 1978 and 2000 that were followed up until 2005. Children with ADHD (n = 206) were identified at the Department of Child and Adolescent Psychiatry. Controls (n = 206) were selected from the study base and were matched for year of birth and maternal country of birth. PFC concentrations were measured in umbilical cord serum samples. The differences of the PFC concentrations between cases and controls were investigated using Wilcoxons paired test. Possible threshold effects (above the upper quartile for perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) and above limit of detection [LOD] for perfluorononanoic acid (PFNA)) were evaluated by conditional logistic regression. Results The median umbilical cord serum concentrations of PFOS were 6.92 ng/ml in the cases and 6.77 ng/ml in the controls. The corresponding concentrations of PFOA were 1.80 and 1.83 ng/ml. No associations between PFCs and ADHD were observed. Odds ratios adjusted for smoking status, parity, and gestational age were 0.81 (95% confidence interval [CI] 0.50 to 1.32) for PFOS, 1.07 (95% CI 0.67 to 1.7) for PFOA, and 1.1 (95% CI 0.75 to 1.7) for PFNA. Conclusions The current study revealed no support for an association between fetal exposure to PFOS, PFOA, or PFNA and ADHD.

Eating Problems and Overlap with ADHD and Autism Spectrum Disorders in a Nationwide Twin Study of 9- and 12-Year-Old Children

Aim. To establish the prevalence of restrictive eating problems, the overlap and association with attention-deficit/hyperactivity disorder (ADHD), and autism spectrum disorders (ASD) and to estimate the heritability of eating problems in a general population sample of twins aged 9 and 12. Methods. Parents of all Swedish 9- and 12-year-old twin pairs born between 1993 and 1998 (n = 12,366) were interviewed regarding symptoms of ADHD, ASD, and eating problems (EAT-P). Intraclass correlations and structural equation modelling were used for evaluating the influence of genetic and environmental factors. Cross-twin, cross-trait correlations were used to indicate a possible overlap between conditions. Results. The prevalence of eating problems was 0.6% in the study population and was significantly higher in children with ADHD and/or ASD. Among children with eating problems, 40% were screened positive for ADHD and/or ASD. Social interaction problems were strongly associated with EAT-P in girls, and impulsivity and activity problems with EAT-P in boys. The cross-twin, cross-trait correlations suggested low correlations between EAT-P and ADHD or EAT-P and ASD. Genetic effects accounted for 44% of the variation in liability for eating problems. Conclusions. In the group with eating problems, there was a clear overrepresentation of individuals with ADHD and/or ASD symptoms.

Reliability and validity of the assessment of neurological soft-signs in children with and without attention-deficit-hyperactivity disorder.

Aim  To study the value and reliability of an examination of neurological soft‐signs, often used in Sweden, in the assessment of children with attention‐deficit–hyperactivity disorder (ADHD), by examining children with and without ADHD, as diagnosed by an experienced clinician using the DSM‐III‐R.

Manganese and selenium concentrations in umbilical cord serum and attention deficit hyperactivity disorder in childhood

Existing evidence on the effects of manganese and selenium during fetal life on neurodevelopmental disorders is inadequate. This study aims to investigate the hypothesized relationship between fetal exposure to manganese and selenium and attention deficit hyperactivity disorder (ADHD) diagnosis in childhood. Children born between 1978 and 2000 with ADHD (n=166) were identified at the Department of Child and Adolescent Psychiatry in Malmö, Sweden. Controls from the same region (n=166) were selected from the Medical Birth Register and were matched for year of birth and maternal country of birth. Manganese and selenium were measured in umbilical cord serum. The median cord serum concentrations of manganese were 4.3μg/L in the cases and 4.1μg/L in the controls. The corresponding concentrations of selenium were 47 and 48μg/L. When the exposures were analyzed as continuous variables no associations between cord manganese or selenium concentration and ADHD were observed. However, children with selenium concentrations above the 90th percentile had 2.5 times higher odds (95% confidence interval 1.3-5.1) of having ADHD compared to those with concentrations between the 10th and 90th percentiles. There was no significant interaction between manganese and selenium exposure (p=0.08). This study showed no association between manganese concentrations in umbilical cord serum and ADHD. The association between ADHD diagnoses in children with relatively high cord selenium was unexpected and should be interpreted with caution.

ADHD symptoms and maturity - a follow-up study in school children.

Aim:  To test the hypothesis that there is a subgroup of children with attention deficit hyperactivity disorder (ADHD) who show a decline in ADHD‐symptoms that is associated with signs of biological maturation, a phenomenon referred to as a ‘maturation catch‐up’.

ADHD symptoms and maturity--a study in primary school children.

Aim: To study if age and non‐behavioural measures of biological maturity have any associations with attention deficit hyperactivity disorder (ADHD).

Treatment of Attention Deficit/Hyperactivity Disorder With Amphetamine: Short-Term Effects on Family Interaction.

Objective: This research seeks to study the impact on family function after 3 months of treatment with amphetamine. Method: A total of 43 children, 6 to 11 years of age, with ADHD were treated with amphetamine for 3 months. Family function was studied before and after treatment by parent self-rating and independent observer ratings of videotaped parent—child interactions. Results: The families with a child with ADHD were found to be more dysfunctional than control families. Families with children with severe ADHD behavior showed evidence of more family dysfunction compared to families with children with less severe ADHD behavior. After 3 months of treatment with amphetamine, the childrens behavior and the mothers well-being and some aspects of parent-reported and observer-rated family functioning improved. Conclusion: This study gives support to the notion that some aspects of family dysfunction may be related to the childs ADHD behavior. (J. of Att. Dis. 2008; 12(1) 83-91)Objective: This research seeks to study the impact on family function after 3 months of treatment with amphetamine. Method: A total of 43 children, 6 to 11 years of age, with ADHD were treated with amphetamine for 3 months. Family function was studied before and after treatment by parent self-rating and independent observer ratings of videotaped parent—child interactions. Results: The families with a child with ADHD were found to be more dysfunctional than control families. Families with children with severe ADHD behavior showed evidence of more family dysfunction compared to families with children with less severe ADHD behavior. After 3 months of treatment with amphetamine, the childrens behavior and the mothers well-being and some aspects of parent-reported and observer-rated family functioning improved. Conclusion: This study gives support to the notion that some aspects of family dysfunction may be related to the childs ADHD behavior.

Vitamin D Status at Birth and Future Risk of Attention Deficit/Hyperactivity Disorder (ADHD)

Objective To investigate whether children with Attention Deficit/Hyperactivity Disorder have lower levels of Vitamin D3 at birth than matched controls. Material Umbilical cord blood samples collected at birth from 202 children later diagnosed with Attention Deficit/Hyperactivity Disorder were analysed for vitamin D content and compared with 202 matched controls. 25-OH vitamin D3 was analysed by liquid chromatography tandem mass spectrometry. Results No differences in cord blood vitamin D concentration were found between children with Attention Deficit/Hyperactivity Disorder (median 13.0 ng/ml) and controls (median 13.5 ng/ml) (p = 0.43). In a logistic regression analysis, Attention Deficit/Hyperactivity Disorder showed a significant association with maternal age (odds ratio: 0.96, 95% confidence interval: 0.92–0.99) but not with vitamin D levels (odds ratio: 0.99, 95% confidence interval: 0.97–1.02). Conclusion We found no difference in intrauterine vitamin D levels between children later developing Attention Deficit/Hyperactivity Disorder and matched control children. However, the statistical power of the study was too weak to detect an eventual small to medium size association between vitamin D levels and Attention Deficit/Hyperactivity Disorder.