[Diagnosis, rehabilitation and development of disability 2000-2019 in Iceland].

Introduction: The disability assessment standard based on medically recognized illnesses or disabilities was introduced in Iceland 1999. The aim of this study is to examine the development of Social Insurance Administration (Tryggingastofnun ríkisins, TR) rulings regarding rehabilitation and disability pensions over a twenty-year period, since its introduction.

Material And Methods: All registered diagnoses in the medical certificates of TR due to the approved rehabilitation or disability pension were examined in the period 2000-2019.

Identification of Genetic Loci Shared Between Attention-Deficit/Hyperactivity Disorder, Intelligence, and Educational Attainment.

Background: Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that is consistently associated with lower levels of educational attainment. A recent large genome-wide association study identified common gene variants associated with ADHD, but most of the genetic architecture remains unknown.

Methods: We analyzed independent genome-wide association study summary statistics for ADHD (19,099 cases and 34,194 controls), educational attainment (N = 842,499), and general intelligence (N = 269,867) using a conditional/conjunctional false discovery rate (FDR) statistical framework that increases power of discovery by conditioning the FDR on overlapping associations.

Identification of genetic overlap and novel risk loci for attention-deficit/hyperactivity disorder and bipolar disorder.

Differential diagnosis between childhood onset attention-deficit/hyperactivity disorder (ADHD) and bipolar disorder (BD) remains a challenge, mainly due to overlapping symptoms and high rates of comorbidity. Despite this, genetic correlation reported for these disorders is low and non-significant. Here we aimed to better characterize the genetic architecture of these disorders utilizing recent large genome-wide association studies (GWAS).

Attention-deficit hyperactivity disorder shares copy number variant risk with schizophrenia and autism spectrum disorder.

Attention-deficit/hyperactivity disorder (ADHD) is a highly heritable common childhood-onset neurodevelopmental disorder. Some rare copy number variations (CNVs) affect multiple neurodevelopmental disorders such as intellectual disability, autism spectrum disorders (ASD), schizophrenia and ADHD. The aim of this study is to determine to what extent ADHD shares high risk CNV alleles with schizophrenia and ASD.

Discovery of the first genome-wide significant risk loci for attention deficit/hyperactivity disorder.

Attention deficit/hyperactivity disorder (ADHD) is a highly heritable childhood behavioral disorder affecting 5% of children and 2.5% of adults. Common genetic variants contribute substantially to ADHD susceptibility, but no variants have been robustly associated with ADHD.

Reproductive fitness and genetic risk of psychiatric disorders in the general population.

The persistence of common, heritable psychiatric disorders that reduce reproductive fitness is an evolutionary paradox. Here, we investigate the selection pressures on sequence variants that predispose to schizophrenia, autism, bipolar disorder, major depression and attention deficit hyperactivity disorder (ADHD) using genomic data from 150,656 Icelanders, excluding those diagnosed with these psychiatric diseases. Polygenic risk of autism and ADHD is associated with number of children.

Electroencephalography as a clinical tool for diagnosing and monitoring attention deficit hyperactivity disorder: a cross-sectional study.

Objectives: The aim of this study was to develop and test, for the first time, a multivariate diagnostic classifier of attention deficit hyperactivity disorder (ADHD) based on EEG coherence measures and chronological age.

Setting: The participants were recruited in two specialised centres and three schools in Reykjavik.

Participants: The data are from a large cross-sectional cohort of 310 patients with ADHD and 351 controls, covering an age range from 5.

Psychiatric disorders in an urban sample of preschool children.

Background: To increase limited epidemiological knowledge of early childhood psychopathology, a study of prevalence estimates and demographic correlates of psychiatric disorders was conducted in a sample of preschool children.

Methods: In a two-stage study, parents of 339 children aged 4-6 years who came for a medical check-up at three primary care centres in Reykjavik were invited to participate. First, the participants were screened with Brigance Screens and the Strengths and Difficulties Questionnaire (SDQ) for parents and teachers.

Rare chromosomal deletions and duplications in attention-deficit hyperactivity disorder: a genome-wide analysis.

Background: Large, rare chromosomal deletions and duplications known as copy number variants (CNVs) have been implicated in neurodevelopmental disorders similar to attention-deficit hyperactivity disorder (ADHD). We aimed to establish whether burden of CNVs was increased in ADHD, and to investigate whether identified CNVs were enriched for loci previously identified in autism and schizophrenia.

Methods: We undertook a genome-wide analysis of CNVs in 410 children with ADHD and 1156 unrelated ethnically matched controls from the 1958 British Birth Cohort.

[The frequency of some factors in pregnancy and delivery for Icelandic children with ADHD].

Objective: ADHD is a well known psychiatric disorder that begins in childhood and frequently persists into adulthood. In the last decade numerous studies have shown the importance of genetic factors in the etiology of ADHD. However other etiological factors seem to be involved.

Validity of self-report and informant rating scales of adult ADHD symptoms in comparison with a semistructured diagnostic interview.

In a study of ADHD symptoms in the relatives of probands diagnosed with ADHD, the validity of self-reported and informant-reported symptoms in childhood and adulthood was investigated with a semistructured diagnostic interview, the Schedule for Affective Disorders and Schizophrenia for School-Age Children (K-SADS) adapted for adults, as a criterion. The participating relatives were 80 women and 46 men aged 17 to 77. Rating scales based on the Diagnostic and Statistical Manual of Mental Disorders (4th ed.