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

Medication for attention deficit-hyperactivity disorder and criminality.

BACKGROUND: Attention deficit-hyperactivity disorder (ADHD) is a common disorder that has been associated with criminal behavior in some studies. Pharmacologic treatment is available for ADHD and may reduce the risk of criminality. METHODS: Using Swedish national registers, we gathered information on 25,656 patients with a diagnosis of ADHD, their pharmacologic treatment, and subsequent criminal convictions in Sweden from 2006 through 2009. We used stratified Cox regression analyses to compare the rate of criminality while the patients were receiving ADHD medication, as compared with the rate for the same patients while not receiving medication. RESULTS: As compared with nonmedication periods, among patients receiving ADHD medication, there was a significant reduction of 32% in the criminality rate for men (adjusted hazard ratio, 0.68; 95% confidence interval [CI], 0.63 to 0.73) and 41% for women (hazard ratio, 0.59; 95% CI, 0.50 to 0.70). The rate reduction remained between 17% and 46% in sensitivity analyses among men, with factors that included different types of drugs (e.g., stimulant vs. nonstimulant) and outcomes (e.g., type of crime). CONCLUSIONS: Among patients with ADHD, rates of criminality were lower during periods when they were receiving ADHD medication. These findings raise the possibility that the use of medication reduces the risk of criminality among patients with ADHD. (Funded by the Swedish Research Council and others.)

Stimulant ADHD medication and risk for substance abuse

Background: There are persistent concerns of long-term effects of stimulant ADHD medication on the development of substance abuse. Methods: Using Swedish national registers, we studied all individuals born between 1960 and 1998 and diagnosed with ADHD (26,249 men and 12,504 women). We investigated the association between stimulant ADHD medication in 2006 and substance abuse during 2009. Substance abuse was indexed by substance-related death, crime, or hospital visits. Results: ADHD medication was not associated with increased rate of substance abuse. Actually, the rate during 2009 was 31% lower among those prescribed ADHD medication in 2006, even after controlling for medication in 2009 and other covariates (hazard ratio: 0.69; 95% confidence interval: 0.57-0.84). Also, the longer the duration of medication, the lower the rate of substance abuse. Similar risk reductions were suggested among children and when investigating the association between stimulant ADHD medication and concomitant short-term abuse. Conclusions: We found no indication of increased risks of substance abuse among individuals prescribed stimulant ADHD medication; if anything, the data suggested a long-term protective effect on substance abuse. Although stimulant ADHD medication does not seem to increase the risk for substance abuse, clinicians should remain alert to the potential problem of stimulant misuse and diversion in ADHD patients. © 2013 Association for Child and Adolescent Mental Health

Binding of adenosine receptor ligands to brain of adenosine receptor knock-out mice: evidence that CGS 21680 binds to A 1 receptors in hippocampus

The adenosine receptor agonist 2-[ p-(2-carboxyethyl)phenylethylamino]-5'- N-ethylcarboxamidoadenosine (CGS 21680) is generally considered to be a selective adenosine A 2A receptor ligand. However, the compound has previously been shown to exhibit binding characteristics that are not compatible with adenosine A 2A receptor binding, at least in brain regions other than the striatum. We have examined binding of [ 3H]CGS 21680 and of antagonist radioligands with high selectivity for adenosine A 1 or A 2A receptors to hippocampus and striatum of mice lacking either adenosine A 1 (A1R (-/-)) or A 2A (A2AR (-/-)) receptors. Both receptor autoradiography and membrane binding techniques were used for this purpose and gave similar results. There were no significant changes in the binding of the A 1 receptor antagonist [ 3H]DPCPX in mice lacking A 2A receptors, or in the binding of the A 2A receptor antagonists [ 3H]SCH 58261 and [ 3H]ZM 241385 in mice lacking A 1 receptors. Furthermore, [ 3H]CGS 21680 binding in striatum was abolished in the A2AR (-/-), and essentially unaffected in striatum from mice lacking A 1 receptors. In hippocampus, however, binding of [ 3H]CGS 21680 remained in the A2AR (-/-), whereas binding was virtually abolished in the A1R (-/-). There were no adaptive alterations in A 2A receptor expression in this region in A1R (-/-) mice. Thus, most of the [ 3H]CGS 21680 binding in hippocampus is dependent on the presence of adenosine A 1 receptors, but not on A 2A receptors, indicating a novel binding site or novel binding mode

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

Consequences of eliminating adenosine A(1) receptors in mice

The second coding exon of the adenosine A, receptor gene was eliminated by homologous recombination. The phenotype of mice (mixed C57B6/129OlaHsd background) was studied, using siblings from matings of heterozygous mice. Among the offspring the ratio between+/+, +/-and -/-animals was 1:2:1. Over the first half-year-at least-growth and viability were the same in all genotypes. Binding of A(1) ligands was eliminated in-/-mice and halved in+/-mice. Blood pressure was increased in-/-mice and this was paralleled by an increase in plasma renin. Heart rate was unaffected, as was contractility. Furthermore, the response of the perfused heart to ischemia was similar in+/+and -/-hearts. However, remote preconditioning was eliminated in-/-mouse hearts. Tubuloglomerular feedback in the kidney was also lost in-/-mice. The analgesic response to a non-selective adenosing receptor agonist was lost in-/-mice, which also showed hyperalgesia in the tail-flick test. There was a slight hypoactivity in-/-mice, but responses to caffeine were essentially normal. The inhibition of excitatory neurotransmission in hippocampus by adenosine was lost in-/-mice and reduced in+/-mice. Responses to ATP were affected similarly. Hypoxic depression of synaptic transmission was essentially eliminated in hippocampus and hypoxic decrease in spinal respiratory neuron firing was markedly reduced. These results show that adenosine A, receptors play a physiologically important role in the kidney, spinal cord, and hippocampus and that they are critically important in the adaptive responses to hypoxia. (C) 2003 Wiley-Liss, Inc