Geographic variation of recorded neurodevelopmental disorders in children and adults.

Introduction: While diagnosis rates of autism spectrum disorders (ASD) and attention deficit hyperactivity disorder (ADHD) vary within countries at a large-scale municipal level, small neighbourhood geographic variation remains understudied. In this nationwide study, we describe the rates of ASD and ADHD diagnoses in children and adults by geographical data zones of approximately 2,500 residents across Denmark.

Methods: We included a population of children born from 1993 through 2020 and an adult population born from 1977 through 2003.

Changing Neighborhood Income Deprivation Over Time, Moving in Childhood, and Adult Risk of Depression.

Importance: Complex biological, socioeconomic, and psychological variables combine to cause mental illnesses, with mounting evidence that early-life experiences are associated with adulthood mental health.

Objective: To evaluate whether changing neighborhood income deprivation and residential moves during childhood are associated with the risk of receiving a diagnosis of depression in adulthood.

Design, Setting, And Participants: This cohort study included the whole population of 1 096 916 people born in Denmark from January 1, 1982, to December 31, 2003, who resided in the country during their first 15 years of life.

Exposure to air pollution and risk of respiratory tract infections in the adult Danish population-a nationwide study.

Objectives: The association between air pollution and risk of respiratory tract infection (RTI) in adults needs to be clarified in settings with low to moderate levels of air pollution. We investigated this in the Danish population between 2004 and 2016.

Methods: We included 3 653 490 persons aged 18-64 years in a nested case-control study.

Multilevel interactions between family and neighbourhood socioeconomic indices in childhood and later risks of self-harm and violent criminality in Denmark: a national cohort study.

Background: A socioeconomically disadvantaged childhood has been associated with elevated self-harm and violent criminality risks during adolescence and young adulthood. However, whether these risks are modified by a neighbourhood's socioeconomic profile is unclear. The aim of our study was to compare risks among disadvantaged young people residing in deprived areas versus risks among similarly disadvantaged individuals residing in affluent areas.

PM air pollution components and mortality in Denmark.

Background: Ambient fine particulate matter (PM) causes millions of deaths every year worldwide. Identification of the most harmful types of PM would facilitate efficient prevention strategies.

Objectives: The aim of this study was to investigate associations between components of PM and mortality in a nation-wide Danish population.

School performance and genetic propensities for educational attainment and depression in the etiology of self-harm: a Danish population-based study.

Background: Poor school performance is linked to higher risks of self-harm. The association might be explained through genetic liabilities for depression or educational attainment. We investigated the association between school performance and self-harm in a population-based sample while assessing the potential influence of polygenic risk scores (PRSs) for depression (PRS) and for educational attainment (PRS).

Maternal Epilepsy and Long-term Offspring Mortality: A Nationwide Cohort Study.

Objective: We examined how maternal epilepsy and use of antiseizure medications in pregnancy was associated with offspring mortality.

Methods: This population-based cohort study included all live- and stillborn singletons in Denmark between 1981 and 2016. We used nation-wide registers to retrieve information on pregnancy characteristics, epilepsy diagnoses, use of antiseizure medications, and mortality.

Urban-Rural Differences in Schizophrenia Risk: Multilevel Survival Analyses of Individual- and Neighborhood-Level Indicators, Urbanicity and Population Density in a Danish National Cohort Study.

Background: Urban-rural differences in schizophrenia risk have been widely evidenced across Western countries. However, explanation of these differences is lacking. We aimed to identify contextual risk factors for schizophrenia that explain urban-rural differences in schizophrenia risk.

Exposure to ambient air pollution during childhood and subsequent risk of self-harm: A national cohort study.

A growing body of evidence indicates that exposure to air pollution not only impacts on physical health but is also linked with a deterioration in mental health. We conducted the first study to investigate exposure to ambient particulate matter with an aerodynamic diameter of less than 2.5 μm (PM) and nitrogen dioxide (NO) during childhood and subsequent self-harm risk.

Adverse Childhood Experiences and Risk of Subsequently Engaging in Self-Harm and Violence towards Other People-"Dual Harm".

The etiology of "dual harm" (the co-occurrence of self-harm and externalized violence in the same individual) is under-researched. Risk factors have mostly been investigated for each behavior separately. We aimed to examine adversities experienced between birth and age 15 years among adolescents and young adults with histories of self-harm and violent criminality, with a specific focus on dual harm.

Long-term exposure to air pollution and mortality in the Danish population a nationwide study.

Background: Studies have shown higher mortality in association with exposure to air pollution. We investigated this association with focus on differences between socioeconomic groups.

Methods: We included all Danes born between 1921 and 1985 aged 30-85 years from 1991 to 2015 ( = 4,401,348).

Exposure to air pollution during childhood and risk of developing schizophrenia: a national cohort study.

Background: Ambient air pollution affects neurological function, but its association with schizophrenia risk is unclear. We investigated exposure to nitrogen oxides (NO) as a whole and nitrogen dioxide (NO) specifically, as well as PM, and PM, during childhood and subsequent schizophrenia risk.

Methods: People born in Denmark from 1980 to 1984 (N=230 844), who were residing in the country on their tenth birthday, and who had two Danish-born parents were followed-up from their tenth birthday until schizophrenia diagnosis or Dec 31, 2016.

Association of Childhood Exposure to Nitrogen Dioxide and Polygenic Risk Score for Schizophrenia With the Risk of Developing Schizophrenia.

Importance: Schizophrenia is a highly heritable psychiatric disorder, and recent studies have suggested that exposure to nitrogen dioxide (NO2) during childhood is associated with an elevated risk of subsequently developing schizophrenia. However, it is not known whether the increased risk associated with NO2 exposure is owing to a greater genetic liability among those exposed to highest NO2 levels.

Objective: To examine the associations between childhood NO2 exposure and genetic liability for schizophrenia (as measured by a polygenic risk score), and risk of developing schizophrenia.

Temporal trends in incidence of hospital-treated self-harm among adolescents in Denmark: national register-based study.

Background: Studies conducted in the UK and in Ireland have reported increased rates of self-harm in adolescent females from around the time of the 2008 economic recession and through periods of subsequent national austerity programme implementation. It is not known if incidence rates have increased similarly in other Western European countries during this period.

Methods: Data from interlinked national administrative registers were extracted for individuals born in Denmark during 1981-2006.

Environmental pollution is associated with increased risk of psychiatric disorders in the US and Denmark.

The search for the genetic factors underlying complex neuropsychiatric disorders has proceeded apace in the past decade. Despite some advances in identifying genetic variants associated with psychiatric disorders, most variants have small individual contributions to risk. By contrast, disease risk increase appears to be less subtle for disease-predisposing environmental insults.

The Danish in-hospital cardiac arrest registry (DANARREST).

The aim of DANARREST is to collect data on processes of care and outcomes for patients with in-hospital cardiac arrest in Denmark, and thereby facilitate and monitor quality and quality improvement initiatives. In-hospital cardiac arrest patients with a clinical indication for cardiopulmonary resuscitation in Denmark. DANARREST includes a number of descriptive variables as well as seven quality of care indicators; four related to processes of care and three related to clinical outcomes.

Multiple adverse outcomes following first discharge from inpatient psychiatric care: a national cohort study.

Background: Discharged psychiatric inpatients are at elevated risk of serious adverse outcomes, but no previous study has comprehensively examined an array of multiple risks in a single cohort.

Methods: We used data from the Danish Civil Registration System to delineate a cohort of all individuals born in Denmark in 1967-2000, who were alive and residing in Denmark on their 15th birthday, and who had been discharged from their first inpatient psychiatric episode at age 15 years or older. Each individual in the discharged cohort was matched on age and sex with 25 comparators without a history of psychiatric admission.

Family income inequalities and trajectories through childhood and self-harm and violence in young adults: a population-based, nested case-control study.

Background: Childhood poverty is associated with elevated later risks for self-directed and externalised violence, but how risks are modified by parental socioeconomic mobility remains unclear. We investigated parental income trajectories during childhood and subsequent risks of self-harm and violent criminality in young adulthood.

Methods: Using Danish national registers, we delineated a nested case-control study of Danish citizens born from Jan 1, 1982, to Dec 31, 2000, with first hospital-treated self-harm episodes and first violent crime convictions at ages 15-33 years.

Experience of Child-Parent Separation and Later Risk of Violent Criminality.

Introduction: Separation from a parent during childhood has been linked with heightened longer-term violence risk, but it remains unclear how this relationship varies by gender, separation subgroup, and age at separation. This phenomenon was investigated by examining a wide array of child-parent separation scenarios.

Methods: National cohort study including individuals born in Denmark, 1971-1997 (N=1,346,772).

Self-harm and violent criminality among young people who experienced trauma-related hospital admission during childhood: a Danish national cohort study.

Background: Development of a better understanding of subsequent pathways for individuals who experienced trauma during childhood might usefully inform clinicians and public health professionals regarding the causes of self-harm and interpersonal violence. We aimed to examine these risks during late adolescence and early adulthood among people admitted to hospital following injuries or poisonings during their childhood.

Methods: This national cohort study included Danish people born between Jan 1, 1977, and Dec 31, 1997, and was linked to the National Patient Register and Psychiatric Central Research Register to identify all people exposed to hospital admissions for injuries or poisonings due to self-harm, interpersonal violence, or accidents before their 15th birthday.