Absolute and relative risks of mental disorders in families: a Danish register-based study.

Background: Relative risk estimates of familial aggregation of many types of mental disorders are available, but absolute risk estimates of familial aggregation of mental disorders remain sparse. The proportion of individuals who develop a mental disorder in the absence of the same disorder in a relative (non-familial cases) has not been examined. We aimed to create comprehensive risk estimates of the familial aggregation of mental disorders.

Construction of a register-based severity index for anorexia nervosa in Denmark: Association with overall and cause-specific mortality.

Background: Considering the high likelihood of chronicity, it is imperative to understand the risk factors and outcomes associated with severe anorexia nervosa (AN), for which Danish registers provide a unique opportunity. We developed a measure of AN severity adapted from clinical literature for use in register-based research.

Methods: The study population included all Danish individuals born between 1963 and 2007 who were diagnosed with AN from 1969 to 2013.

Predictors of Anorexia Nervosa and Obsessive-Compulsive Disorder Comorbidity and Order of Diagnosis in a Danish National Cohort.

Objective: Anorexia nervosa (AN) and obsessive-compulsive disorder (OCD) are highly comorbid; however, limited research has examined etiological pathways specific to individuals with AN developing OCD or individuals with OCD developing AN. This exploratory study aimed to identify factors influencing AN-OCD comorbidity with a focus on the order of diagnosis.

Method: Using Danish national registers, 6449 individuals with AN and 9352 individuals with OCD were examined to assess the risk of subsequent OCD and AN.

Convergent evidence linking neonatal vitamin D status and risk of neurodevelopmental disorders: a Danish case-cohort study.

Background: There is growing evidence linking neonatal vitamin D deficiency to an increased risk of schizophrenia, ADHD, and autism spectrum disorder (ASD). The aim of this study was to examine the association between two vitamin D biomarkers (25 hydroxyvitamin D [25(OH)D] and vitamin D-binding protein [DBP], and their related genetic correlates) and the risk of six mental disorders.

Methods: We used a population-based, case-cohort sample of all individuals born in Denmark between 1981 and 2005.

Psychiatric and somatic morbidity patterns among patients diagnosed with anorexia nervosa and the risk of involuntary treatment: register-based cohort study.

Background: Involuntary treatment for patients with anorexia nervosa is common and lifesaving, but also highly intrusive. Understanding how morbidity patterns relate to involuntary treatment can help minimise its use.

Aim: We estimate the relative risk of involuntary treatment according to morbidity profiles in patients with anorexia nervosa.

Descriptives and Genetic Correlates of Eating Disorder Diagnostic Transitions and Presumed Remission in the Danish Registry.

Background: Eating disorders (EDs) are serious psychiatric disorders with an estimated 3.3 million healthy life-years lost worldwide yearly. Understanding the course of illness, diagnostic transitions and remission, and their associated genetic correlates could inform both ED etiology and treatment.

Parental psychopathology before and after the child's diagnosis of a mental disorder: a population-based matched cohort study.

Background: More research is needed to understand psychopathology among parents of children with mental disorders in the years before and after the child is diagnosed. Here, we estimated the risk of mental disorders and psychotropic medication use in parents of children with versus without mental disorders and the temporal associations between child and parental psychopathology.

Methods: We conducted a population-based matched cohort study using Danish register data.

The role of co-occurring conditions and genetics in the associations of eating disorders with attention-deficit/hyperactivity disorder and autism spectrum disorder.

Eating disorders (EDs) commonly co-occur with other psychiatric and neurodevelopmental disorders including attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD); however, the pattern of family history and genetic overlap among them requires clarification. This study investigated the diagnostic, familial, and genetic associations of EDs with ADHD and ASD. The nationwide population-based cohort study included all individuals born in Denmark, 1981-2008, linked to their siblings and cousins.

Maternal mental disorders and neonatal outcomes: Danish population-based cohort study.

Background: Previous studies have indicated associations between maternal mental disorders and adverse birth outcomes; however, these studies mainly focus on certain types of mental disorders, rather than the whole spectrum.

Aims: We aimed to conduct a broad study examining all maternal mental disorder types and adverse neonatal outcomes which is needed to provide a more complete understanding of the associations.

Method: We included 1 132 757 liveborn singletons born between 1997 and 2015 in Denmark.

White blood cell counts, ratios, and C-reactive protein among individuals with schizophrenia spectrum disorder and associations with long-term outcomes: a population-based study.

Background: Immune mechanisms are associated with adverse outcomes in schizophrenia; however, the predictive value of various peripheral immune biomarkers has not been collectively investigated in a large cohort before.

Objective: To investigate how white blood cell (WBC) counts, ratios, and C-Reactive Protein (CRP) levels influence the long-term outcomes of individuals with schizophrenia spectrum disorder (SSD).

Methods: We identified all adults in the Central Denmark Region during 1994-2013 with a measurement of WBC counts and/or CRP at first diagnosis of SSD.

Diagnosed eating disorders in Danish registers - incidence, prevalence, mortality, and polygenic risk.

Eating disorders are a group of severe and potentially enduring psychiatric disorders associated with increased mortality. Compared to other severe mental illnesses, they have received relatively limited research attention. Epidemiological studies often only report relative measures despite these being difficult to interpret having limited practical use.

A comprehensive analysis of age of onset and cumulative incidence of mental disorders: A Danish register study.

Background: The age of onset (AOO), incidence and cumulative incidence of mental disorders are critical epidemiological measures, providing essential insights into the development and course of these disorders across the lifespan. This study aims to provide up-to-date estimates of the AOO, age-specific incidence, and cumulative incidence for a comprehensive range of mental disorders using data from Danish registers.

Methods: We conducted a follow-up study encompassing all Danish residents from January 1, 2004, to December 31, 2021, totaling 91,613,465 person-years.

Inpatient admissions and mortality of anorexia nervosa patients according to their preceding psychiatric and somatic diagnoses.

Objective: Anorexia nervosa (AN) is associated with increased risk of mortality, but little is known about the risk of inpatient admissions and mortality outcomes in individuals with diagnoses of both AN and other psychiatric and somatic conditions. We aimed to investigate the inpatient admissions and mortality among people with AN and other diagnosed conditions using Danish national registers.

Method: This retrospective cohort study included individuals diagnosed with AN in Denmark, born 1977-2010.

Identification of women at high risk of postpartum psychiatric episodes: A population-based study quantifying relative and absolute risks following exposure to selected risk factors and genetic liability.

Background: We quantified relative and absolute risks of postpartum psychiatric episodes (PPE) following risk factors: Young age, past personal or family history of psychiatric disorders, and genetic liability.

Methods: We conducted a register-based study using the iPSYCH2012 case-cohort sample. Exposures were personal history of psychiatric episodes prior to childbirth, being a young mother (giving birth before the age of 21.

Antidepressant treatment in pregnancy: a Danish registry linkage study in pregnant women with pre-existing obsessive-compulsive disorder.

The association between antidepressant continuation during pregnancy and postpartum mental health in women with obsessive-compulsive disorder (OCD) is uncertain. We identified 1317 women with live-birth singleton pregnancies and having outpatient/inpatient visits for OCD in the 4 years pre-pregnancy from the Danish registries. We defined three groups based on antidepressant prescriptions filled in the 2 years before pregnancy to delivery: (i) unexposed (n = 449); (ii) discontinuers (n = 346), i.

Risk factors for anorexia nervosa: A population-based investigation of sex differences in polygenic risk and early life exposures.

Objective: To examine sex differences in risk factors for anorexia nervosa (AN).

Method: This population-based study involved 44,743 individuals (6,239 AN cases including 5,818 females and 421 males, and 38,504 controls including 18,818 females and 19,686 males) born in Denmark between May 1981 and December 2009. Follow-up began on the individual's sixth birthday and ended at AN diagnosis, emigration, death, or December 31, 2016, whichever occurred first.

Effect of mode of birth on development of mental disorders in the offspring.

Objective: Increasing rates of caesarean sections has led to concerns about long-term effects on the offspring's health, and it has been hypothesised that caesarean section induced differences in the child's microbiota could potentially increase the risk of mental disorders.

Methods: Nationwide Danish cohort study of 2,196,687 births was conducted between 1980 and 2015, with 38.5 million observation-years.

Psychiatric visits during the postpartum year in women with eating disorders who continue or discontinue antidepressant treatment in pregnancy.

Objective: To determine the association between continued antidepressant use in pregnancy and postpartum psychiatric visits for eating (ED) or mood/anxiety disorders in women with preexisting ED.

Method: Using Danish health registry data (1998-2015), we identified 3529 pregnancies in women with ED prepregnancy: (i) 564 with continued antidepressant use before and during pregnancy; (ii) 778 with discontinued antidepressants before pregnancy; (iii) 2137 unexposed. Outpatient and inpatient postpartum visits for an ED or a mood/anxiety disorder constituted the outcome measures.

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.