Shared familial risk for type 2 diabetes mellitus and psychiatric disorders: a nationwide multigenerational genetics study.

Background: Psychiatric disorders and type 2 diabetes mellitus (T2DM) are heritable, polygenic, and often comorbid conditions, yet knowledge about their potential shared familial risk is lacking. We used family designs and T2DM polygenic risk score (T2DM-PRS) to investigate the genetic associations between psychiatric disorders and T2DM.

Methods: We linked 659 906 individuals born in Denmark 1990-2000 to their parents, grandparents, and aunts/uncles using population-based registers.

ADHD medication discontinuation and persistence across the lifespan: a retrospective observational study using population-based databases.

Background: Although often intended for long-term treatment, discontinuation of medication for ADHD is common. However, cross-national estimates of discontinuation are missing due to the absence of standardised measures. The aim of this study was to determine the rate of ADHD treatment discontinuation across the lifespan and to describe similarities and differences across countries to guide clinical practice.

The bidirectional association between psychiatric disorders and sheltered homelessness.

Background: Psychiatric disorders and homelessness are related, but temporal associations are unclear. We aimed to explore the overlap between hospital-based psychiatric disorders and sheltered homelessness.

Methods: This population-based cohort study was conducted using the Danish registers e.

Interplay of ADHD Polygenic Liability With Birth-Related, Somatic, and Psychosocial Factors in ADHD: A Nationwide Study.

Objective: Attention deficit hyperactivity disorder (ADHD) is a multifactorial neurodevelopmental disorder, yet the interplay between ADHD polygenic risk scores (PRSs) and other risk factors remains relatively unexplored. The authors investigated associations, confounding, and interactions of ADHD PRS with birth-related, somatic, and psychosocial factors previously associated with ADHD.

Methods: Participants included a random general population sample (N=21,578) and individuals diagnosed with ADHD (N=13,697) from the genotyped Danish iPSYCH2012 case cohort, born between 1981 and 2005.

High polygenic predisposition for ADHD and a greater risk of all-cause mortality: a large population-based longitudinal study.

Background: Attention deficit hyperactivity disorder (ADHD) is a highly heritable, neurodevelopmental disorder known to associate with more than double the risk of death compared with people without ADHD. Because most research on ADHD has focused on children and adolescents, among whom death rates are relatively low, the impact of a high polygenic predisposition to ADHD on accelerating mortality risk in older adults is unknown. Thus, the aim of the study was to investigate if a high polygenetic predisposition to ADHD exacerbates the risk of all-cause mortality in older adults from the general population in the UK.

Temporal changes in sex- and age-specific incidence profiles of mental disorders-A nationwide study from 1970 to 2016.

Objective: Information on mental disorders over time is critical for documenting changes in population burden, and aiding understanding of potential causal and non-causal factors. The aim of this study was to provide temporal changes in the sex- and age-specific incidence rates (IR) of mental disorders diagnosed in Danish hospitals during five decades and investigate whether such changes may be attributable to changes in administrative reporting practice.

Methods: This population-based cohort study included all people living in Denmark between 1970 and 2016.

Effect of antipsychotics on mortality risk in patients with dementia with and without comorbidities.

Background: We investigated the mortality risk associated with the initiation of antipsychotic treatment among patients with dementia and whether comorbidities related to the cardiovascular system and diabetes interact with antipsychotic treatment to increase the mortality risk beyond the risk of death independently associated with antipsychotics and comorbidity alone.

Methods: We designed a matched cohort study using nationwide registry data. All Danish residents aged 65-95 years diagnosed with dementia between 2009 and 2014 were included.

Early-Life Injuries and the Development of Attention-Deficit/Hyperactivity Disorder.

To estimate phenotypic and familial association between early-life injuries and attention-deficit/hyperactivity disorder (ADHD) and the genetic contribution to the association using polygenic risk score for ADHD (PRS-ADHD) and genetic correlation analyses. Children born in Denmark between 1995-2010 (n = 786,543) were followed from age 5 years until a median age of 14 years (interquartile range: 10-18 years). Using diagnoses, we estimated hazard ratios (HRs) and absolute risks of ADHD by number of hospital/emergency ward-treated injuries by age 5.

Transdiagnostic Perspective of Impulsivity and Compulsivity in Obesity: From Cognitive Profile to Self-Reported Dimensions in Clinical Samples with and without Diabetes.

Impulsive and compulsive behaviors have both been observed in individuals with obesity. The co-occurrence of obesity and type 2 diabetes (T2D) is more strongly associated with impulsivity, although there are no conclusive results yet. A multidimensional assessment of impulsivity and compulsivity was conducted in individuals with obesity in the absence or presence of T2D, compared with healthy, normal-weight individuals, with highly impulsive patients (gambling disorders), and with highly compulsive patients (anorexia nervosa).

Genetic, Clinical, and Sociodemographic Factors Associated With Stimulant Treatment Outcomes in ADHD.

Objective: Stimulant medications are effective for treating attention deficit hyperactivity disorder (ADHD), yet discontinuation and switch to nonstimulant ADHD medications are common. This study aimed to identify genetic, clinical, and sociodemographic factors influencing stimulant treatment initiation, discontinuation, and switch to nonstimulants in individuals with ADHD.

Methods: The authors obtained genetic and national register data for 9,133 individuals with ADHD from the Danish iPSYCH2012 sample and defined stimulant treatment initiation, discontinuation, and switch from prescriptions.

Association of Benzodiazepines and Antidepressants With 180-Day Mortality Among Patients With Dementia Receiving Antipsychotic Pharmacotherapy: A Nationwide Registry-Based Study.

Objective: Antipsychotic drugs are known to increase mortality among patients with dementia. Many patients receive concomitant treatment with other psychotropic agents. The aim of this retrospective cohort study was to investigate the impact of benzodiazepines and antidepressants on the risk of death in patients with dementia initiating antipsychotic drug treatment.

No evidence of associations between genetic liability for schizophrenia and development of cannabis use disorder.

Background: Cannabis use and cannabis use disorder (CUD) is increased in patients with schizophrenia. It is important to establish if this is explained by non-causal factors, such as shared genetic vulnerability. We aimed to investigate whether the polygenic risk scores (PRS) for schizophrenia and other psychiatric disorders would predict CUD in controls, patients with schizophrenia, and patients with other psychiatric disorders.

Genetic liability to ADHD and substance use disorders in individuals with ADHD.

Aims: 1) To investigate whether genetic liability to attention-deficit/hyperactivity disorder (ADHD), indexed by polygenic risk scores for ADHD (PRS-ADHD), is associated with substance use disorders (SUD) in individuals with ADHD. 2) To investigate whether other individual- or family-related risk factors for SUD could mediate or confound this association.

Design: Population-based cohort study SETTING AND PARTICIPANTS: ADHD cases in the iPSYCH sample (a Danish case-cohort sample of genotyped cases with specific mental disorders), born in Denmark between 1981 and 2003 (N = 13 116).

Incidence Rates and Cumulative Incidences of the Full Spectrum of Diagnosed Mental Disorders in Childhood and Adolescence.

Importance: Knowledge about the epidemiology of mental disorders in children and adolescents is essential for research and planning of health services. Surveys can provide prevalence rates, whereas population-based registers are instrumental to obtain precise estimates of incidence rates and risks.

Objective: To estimate age- and sex-specific incidence rates and risks of being diagnosed with any mental disorder during childhood and adolescence.

Schizophrenia polygenic risk scores, urbanicity and treatment-resistant schizophrenia.

Introduction: To investigate the impact of a polygenic risk score for schizophrenia (PRS-SZ) and urbanicity on the risk of treatment-resistant schizophrenia (TRS) in people diagnosed with schizophrenia and to evaluate the association between PRS-SZ and TRS across levels of urbanicity.

Methods: Cohort study of people born after 1981 with a first registered diagnosis of schizophrenia between 1996 and 2012 using Danish population registry data. Through linkage to genome-wide data, we calculated PRS-SZ based on a Psychiatric Genomics Consortium meta-analysis.

Changes in the Prevalence of Polypharmacy in People with and without Dementia from 2000 to 2014: A Nationwide Study.

Background: Polypharmacy, the use of multiple medications, has become increasingly widespread. Information on time trends in polypharmacy in people with dementia is limited, although they may be more susceptible to risks associated with polypharmacy.

Objective: To examine changes in the prevalence of polypharmacy and excessive polypharmacy in people with dementia compared to changes in people without dementia.

Otitis media, antibiotics, and risk of autism spectrum disorder.

Otitis media infections and antibiotic treatment have been linked to the risk of developing autism spectrum disorder. Broad-spectrum antibiotics may alter the composition of the gut flora microbiota, which is hypothesized to be involved in the regulation of the immune system. This study examines the interplay among otitis media, antibiotics, and the subsequent risk of developing autism.

Polypharmacy and Potentially Inappropriate Medication in People with Dementia: A Nationwide Study.

Background: Polypharmacy (use of ≥5 different medications) and potentially inappropriate medication (PIM) are well-known risk factors for numerous negative health outcomes. However, the use of polypharmacy and PIM in people with dementia is not well-described.

Objective: To examine the prevalence of polypharmacy and PIM in older people with and without dementia in a nationwide population.

Validation of an algorithm-based definition of treatment resistance in patients with schizophrenia.

Large-scale pharmacoepidemiological research on treatment resistance relies on accurate identification of people with treatment-resistant schizophrenia (TRS) based on data that are retrievable from administrative registers. This is usually approached by operationalising clinical treatment guidelines by using prescription and hospital admission information. We examined the accuracy of an algorithm-based definition of TRS based on clozapine prescription and/or meeting algorithm-based eligibility criteria for clozapine against a gold standard definition using case notes.

Association between global functioning at first schizophrenia diagnosis and treatment resistance.

Aim: Several factors such as age, gender, urbanicity and clinical treatment setting have been associated with treatment-resistant schizophrenia (TRS). We examined the association between the Global Assessment of Functioning (social Functioning [GAF-F]) score at first schizophrenia diagnosis and TRS and explored whether level of functioning could partially explain the known associations.

Methods: A nationwide population-based cohort study among individuals, who had a GAF-F score at first schizophrenia diagnosis.