Relative immaturity and ADHD : findings from nationwide registers, parent- and self-reports

BACKGROUND: We addressed if immaturity relative to peers reflected in birth month increases the likelihood of ADHD diagnosis and treatment. METHODS: We linked nationwide Patient and Prescribed Drug Registers and used prospective cohort and nested case-control designs to study 6-69 year-old individuals in Sweden from July 2005 to December 2009 (Cohort 1). Cohort 1 included 56,263 individuals diagnosed with ADHD or ever used prescribed ADHD-specific medication. Complementary population-representative cohorts provided DSM-IV ADHD symptom ratings; parent-reported for 10,760 9-year-old twins born 1995-2000 from the CATSS study (Cohort 2) and self-reported for 6,970 adult twins age 20-47 years born 1959-1970 from the STAGE study (Cohort 3). We calculated odds ratios (OR:s) for ADHD across age for individuals born in November/December compared to January/February (Cohort 1). ADHD symptoms in Cohorts 2 and 3 were studied as a function of calendar birth month. RESULTS: ADHD diagnoses and medication treatment were both significantly more common in individuals born in November/December versus January/February; peaking at ages 6 (OR: 1.8; 95% CI: 1.5-2.2) and 7 years (OR: 1.6; 95% CI: 1.3-1.8) in the Patient and Prescribed Drug Registers, respectively. We found no corresponding differences in parent- or self-reported ADHD symptoms by calendar birth month. CONCLUSION: Relative immaturity compared to class mates might contribute to ADHD diagnosis and pharmacotherapy despite absence of parallel findings in reported ADHD symptom loads by relative immaturity. Increased clinical awareness of this phenomenon may be warranted to decrease risk for imprecise diagnostics and treatment. We speculate that flexibility regarding age at school start according to individual maturity could reduce developmentally inappropriate demands on children and improve the precision of ADHD diagnostic practice and pharmacological treatment.Swedish Research Council (2010-3184)Karolinska Institutet Center of Neurodevelopmental Disorders (KIND)Accepte

Childhood neurodevelopmental problems and adolescent bully victimization : population-based, prospective twin study in Sweden

Bully victimization is a common problem among children with neurodevelopmental disorders, including attention deficit/hyperactivity disorder and autism spectrum disorder. Previous research was mostly cross-sectional and seldom accounted for co-morbid psychopathology, which makes it difficult to draw conclusions about causality and specificity of any association. Using a genetically informative prospective design, we investigated the association between various neurodevelopmental problems (NDPs) in childhood and bully victimization in adolescence, and the relative contributions of genetic and environmental factors to this association. We obtained parent-reports of NDPs at age 9/12 years and self-reported bully victimization at age 15 for 3,921 children participating in the The Child and Adolescent Twin Study in Sweden (CATSS). Structural equation modelling was used to control for NDP co-morbidity and bully victimization at baseline. Cholesky decomposition was used to analyse genetic and environmental contributions to observed associations. Because most of the NDPs were associated to later bully victimization, a common effect of all NDPs was summarized into a general NDP factor. Controlling for this general factor, only problems with social interaction and motor control uniquely predicted subsequent bully victimization in girls. General and unique associations were influenced by both genetic and unique environmental factors. NDPs in general and social interaction and motor problems in particular predicted later bully victimization. The longitudinal design and twin analyses indicated that these associations might be causal. Knowledge of these vulnerabilities may be important when designing risk assessment and prevention strategies.The Swedish Council for Working Life and Social ResearchThe Research Council of the Swedish National Alcohol MonopolyThe Söderström-Königska FoundationFunds under the ALF agreementThe Swedish Research CouncilAccepte

The Swedish Twin Registry : establishment of a biobank and other recent developments

The Swedish Twin Registry (STR) today contains more than 194,000 twins and more than 75,000 pairs have zygosity determined by an intra-pair similarity algorithm, DNA, or by being of opposite sex. Of these, approximately 20,000, 25,000, and 30,000 pairs are monozygotic, same-sex dizygotic, and opposite-sex dizygotic pairs, respectively. Since its establishment in the late 1950s, the STR has been an important epidemiological resource for the study of genetic and environmental influences on a multitude of traits, behaviors, and diseases. Following large investments in the collection of biological specimens in the past 10 years we have now established a Swedish twin biobank with DNA from 45,000 twins and blood serum from 15,000 twins, which effectively has also transformed the registry into a powerful resource for molecular studies. We here describe the main projects within which the new collections of both biological samples as well as phenotypic measures have been collected. Coverage by year of birth, zygosity determination, ethnic heterogeneity, and influences of in vitro fertilization are also described.VetenskapsrådetNIHSSFHjärt- och LungfondenAstma- och AllergiförbundetAccepte

”Det får inte bli för mycket av det här datoriserandet.” – En kvalitativ studie av digitaliseringens påverkan på generationsskillnader, med fokus på kommunikation

Titel ”Det får inte bli för mycket av det här datoriserandet.” – En kvalitativ studie av digitaliseringens påverkan på generationsskillnader, med fokus på kommunikation Författare Philip Bernåker & Julia Halldner Uppdragsgivare JMG, Medieinriktningen på lärarutbildningen, Göteborgs universitet Kurs Examensarbete i Medie- och kommunikationsvetenskap vid institutionen för journalistik, medier och kommunikation Göteborgs universitet Termin Vårterminen 2011 Handledare Jenny Wiik Sidantal 40, inklusive bilaga Antal ord 15 716 Syfte Att undersöka generationsskillnader gällande kommunikation i och med digitaliseringen. (Utifrån en lärares synvinkel) Metod Kvalitativ undersökning i form av samtalsintervjuer Material Sex stycken samtalsintervjuer med gymnasielärare i Göteborg Huvudresultat Studien visar att lärarna anser att digitaliseringen är ett problem och att den har påverkat generationsskillnader negativt. Lärarna anser även att kommunikationen har påverkats av digitaliseringen, både positivt och negativt. Dock kommer ungdomar alltid ses på ett visst sätt – lata, bekväma och i behov av instruktioner. Vår studie ökar medvetenheten kring problematiken som digitaliseringen har medfört

Physiology and pathophysiology of central adenosine A1 and A2A receptors

The aim of this thesis was to further investigate the individual roles of central adenosine A1 and A2A receptors in the physiological and pathophysiological effects of adenosine. In addition, the characteristics of different adenosine receptor ligands were studied. For these purposes pharmacological tools as well as mice lacking adenosine A1 and/or A2A receptors were used. Both adenosine A1 receptor knock-out and adenosine A1/A2A receptor double knock-out mice survived fetal life and developed no major defects. No significant change in baseline motor activity was seen in these knock-out mice. In situ hybridization and receptor autoradiography confirmed that the adenosine A1 receptor knock-out did not express any central adenosine A1 receptors. Adenosine A1 receptor heterozygotes expressed half the amount of the receptor. The same was due for the adenosine A2A receptor heterozygote regarding the adenosine A2A receptor expression. The expression of adenosine A2A receptors was not affected by absence of the adenosine A1 receptors. Rats that were sleep-deprived for 3 or 6 hours had altered levels of both adenosine A1 and A2A receptor mRNA. Adenosine A1 receptor mRNA was up-regulated specifically in the horizontal limb of the diagonal band in the basal forebrain. This up-regulation was not seen at the protein level. On the contrary, adenosine A2A receptor mRNA was down-regulated, and this was accompanied with a decrease in receptor binding after 3 but not 6 hours of sleep-deprivation. The alterations of the adenosine A2A receptor expression was observed only in the olfactory tubercle. The sleep pattern and the response to sleep deprivation was studied in mice lacking adenosine A1 receptors. These mice did unexpectedly not differ from their wild-type siblings in these respects. Adenosine A2A receptor knock-outs were more sensitive to hypoxia-ischemia than wild-type mice. They developed an aggravated brain damage, which resulted in altered behavior later in life. Adenosine A2A receptor knock-outs exposed to hypoxia-ischemia showed altered behavior in the open field test and performed less well in the rotarod test. Chronic administration of the locomotor activity stimulating adenosine A2A receptor antagonist SCH 58261 was given to rats. In contrast to previous studies with the non-selective adenosine antagonist caffeine, no tolerance developed to the motor stimulating effect after repeated injections of the drug. The locomotor effects of caffeine were analyzed in mice lacking adenosine A1 receptors. The dose-response curve for caffeine seemed shifted to the left, whereas response to high dose caffeine was unaltered in the knock-out. No locomotor stimulating effect was observed in adenosine A1/A2A receptor double knock-out mice in congruence with mice lacking only the adenosine A2A receptor. Finally, the selectivity of the adenosine receptor ligands DPCPX (A1 antagonist), SCH 58261(A2A antagonist), ZM 241385(A2A antagonist) and CGS 21680(A2A agonist) were tested by means of receptor binding in adenosine receptor knock-out brains. DPCPX did not bind to brains from adenosine A1 receptor knock-outs, whereas SCH 58261 and ZM 241385 did not bind in brains from adenosine A2A receptor knock-outs. CGS 21680 did however not bind in the striatum from adenosine A2A receptor knock-outs, but extra-striatal bindin

Disrupted Attention to Other’s Eyes is Linked to Symptoms of ADHD in Childhood

Attention-deficit/hyperactivity disorder (ADHD) is associated with impaired social interaction. Other’s eyes are important for understanding the social world. Here, we examined concurrent and longitudinal links between attention to other’s eyes and symptoms of ADHD and comorbid externalizing and internalizing symptoms. Eighty-two 8 to 13-year-old children (40% with ADHD) participated. The latency to a first gaze shift to and away from the eye region of human faces, when primed to look at either the eyes or the mouth, was recorded with eye tracking. Parents rated ADHD, externalizing and internalizing symptoms at the time of testing and at 2-year follow-up. The results show that longer looking at the eyes before reorienting was specifically associated with concurrent and future symptoms of inattention, even when accounting for comorbid symptoms. We conclude that the temporal microstructure of attention to other’s eyes is altered in children with symptoms of ADHD, which may contribute to social impairments

The adenosine A1 receptor contributes to the stimulatory, but not the inhibitory effect of caffeine on locomotion: a study in mice lacking adenosine A1 and/or A2A receptors.

Caffeine has biphasic effects on locomotion, and blockade of the adenosine A(2A) receptor (A2AR) is necessary for the stimulatory effect of low doses of caffeine, but not for the locomotor depressant effect observed at high doses. We wanted to elucidate the role of the adenosine A(1) receptor (A1R) in mediating the locomotor effects of increasing doses of caffeine using wild-type mice (A1R(WT)), mice heterozygous for (A1R(HET)), and mice lacking the adenosine A(1) receptor (A1R(KO)). Caffeine had the typical biphasic dose-effect relationship in all three genotypes, but the stimulatory action of caffeine was facilitated in the A1R(KO) mice. In order to investigate the interaction between blockade of A1Rs and A2ARs, mice lacking both receptors (A1R(KO)/A2AR(KO)) were tested. Regardless of A1R genotype, animals lacking A2AR were not stimulated by caffeine, whereas animals heterozygous for A2AR were. As expected, the A1R is not crucial for the stimulatory effect of caffeine, but seems to modulate the effect of caffeine exerted via A2AR blockade. Furthermore, these results suggest that the inhibitory effect of high doses of caffeine is due neither to blockade of the A1R, nor of the A2AR, and an effect independent of these adenosine receptors is likely.Comparative StudyJournal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe