Merete Osler

University of Copenhagen · Department of Public Health

Introduction Cannabis is by far the most widely used and abused drug listed on the Drug Enforcement Administration's Schedule I, which includes drugs with a high potential for abuse. There is evidence of short‐term negative effects of cannabis use on cognition, but only a limited number of studies have explored the association between cannabis use...

Objectives: To investigate the influence of wine, beer, and spirits consumption, respectively, on non-pathological, age-related cognitive decline from young adulthood to late midlife in a large follow-up study of Danish men. Methods: The study includes 2456 middle-aged Danish men from the Lifestyle and Cognition Follow-up study 2015, with informati...

Background We investigated whether having children and their socioeconomic resources are associated with receiving coronary angiogram (CAG) and coronary artery bypass graft surgery (CABG) or percutaneous coronary intervention (PCI) among older adults with non-ST elevation myocardial infarction (NSTEMI) and unstable angina pectoris. Methods The stu...

Background It remains uncertain whether long-term use of benzodiazepines is associated with age-related cognitive decline, and if cognitive ability in early life is the driver of any association. This study examines the association of cognitive ability in young adulthood with later use of benzodiazepines and explores whether the use of benzodiazepi...

Background While several risk factors for schizophrenia have been identified, their individual impacts are rather small. The relative independent and cumulative impacts of multiple risk factors on disease risk and age of onset warrant further investigation. Study design We conducted a register-based case–control study including all individuals rec...

Importance Large-scale evidence for the efficacy of continuation and maintenance electroconvulsive therapy (c/mECT) is lacking. Objective To provide an exhaustive and naturalistic insight into the real-world outcomes and the cost-effectiveness of c/mECT in a large dataset. Design, Setting, and Participants This cohort study included all patients...

This study examines the hypotheses that the traits of higher IQ, longer education and taller height are associated with lower risk of death as compared to traits of low IQ, short education, and short height in men with schizophrenia compared to men without schizophrenia. In total, 937,919 men born 1939-59 and 1983–1997 with information from conscri...

Introduction: Seasonality in depressive and bipolar disorders, are recognized in the ICD-10/11 and DSM-5 diagnostic systems. The existence of a seasonal pattern of hospital diagnosis of major depression, bipolar disorder and prescription of antidepressant medications has not been evaluated in the Danish population. Methods: We retrieved date and...

Background Empirical evaluation of inverse probability weighting (IPW) for self-selection bias correction is inaccessible without the full source population. We aimed to: (i) investigate how self-selection biases frequency and association measures and (ii) assess self-selection bias correction using IPW in a cohort with register linkage. Methods T...

Importance Becoming a first-time parent is a major life-changing event and can be challenging regardless of the pregnancy outcome. However, little is known how different adverse pregnancy outcomes affect the father’s risk of psychiatric treatment post partum. Objective To examine the associations of adverse pregnancy outcomes with first-time psych...

Background Evidence suggests that cannabis may be a causal factor for development of schizophrenia. We aimed to investigate whether use of antipsychotic medication, benzodiazepines, and psychiatric service use differs among patients with schizophrenia depending on whether psychosis was precipitated by a diagnosis of cannabis use disorder (CUD). Met...

Aim: The mechanisms behind the association between adult offspring’s socioeconomic position and their parents’ mortality are not well understood. This study investigates lifestyle-related diseases as a potential mediating pathway between adult offspring’s education and parental mortality. Methods: This nationwide register-based cohort study consist...

Background Accumulation of β-amyloid (Aβ) in the brain is a hallmark of Alzheimer’s Disease (AD). Cerebral deposition of Aβ initiates deteriorating pathways which eventually can lead to AD. However, the exact mechanisms are not known. A possible pathway could be that Aβ affects the cerebral vessels, causing inadequate cerebrovascular function. In t...

Background With aging populations worldwide, identification of predictors of age-related cognitive decline is becoming increasingly important. The Danish Aging and Cognition Cohort (DanACo) including more than 5000 Danish men was established to investigate predictors of age-related cognitive decline from young adulthood to late mid-life. Construct...

Background: Prior studies comparing the mental healthcare utilisation (MHU) of Danish formerly deployed military personnel (FDP) with the general population have not included data on psychotherapy through the Defence or talking therapy with the general practitioner. This study included these and several other data sources in a comprehensive compari...

Aims Alzheimer’s disease (AD) is characterized by the accumulation of amyloid beta (A β ) in the brain. The deposition of A β is believed to initiate a detrimental cascade, including cerebral hypometabolism, accelerated brain atrophy, and cognitive problems—ultimately resulting in AD. However, the timing and causality of the cascade resulting in AD...

Background Evidence‐based use of antidepressant medications is of major clinical importance. We aimed to uncover precription patterns in a large cohort of patients with unipolar depression. Material and Methods Using Danish nationwide registers, we identified individuals with a first‐time hospital diagnosis of unipolar depression between January 1...

Objective: The authors investigated the frequency and determinants of long-term use and risk of dose escalation of benzodiazepines and benzodiazepine-related drugs (benzodiazepine receptor agonists, or BZRAs). Methods: All adults ages 20-80 years living in Denmark on January 1, 2000 (N=4,297,045) were followed for redeemed prescriptions of BZRAs...

Objective: To evaluate the risk of falls and fractures in users of benzodiazepines, Z-drugs, or melatonin. Methods: We followed 699,335 adults with a purchase of benzodiazepines, Z-drugs, or melatonin in the Danish National Prescription Registry between 2003 and 2016 for falls and fractures in the Danish National Patient Registry between 2000 an...

Aims: Socioeconomic resources and family support have been shown to improve adherence to treatment in people with type 2 diabetes (T2D), which is associated with a lower risk of diabetes-related complications and death. We investigated the associations of having children and their educational level with diabetes-related complications and death amo...

Background It is well described that there is social inequality in the disease course of chronic obstructive pulmonary disease (COPD), but the impact of social relations is less explored. We aimed to investigate the impact of adult offspring and their educational level on readmission and death among older adults with COPD. Methods In total, 71 084...

Background: Major Depressive Disorder (MDD) is a heterologous disease in respect to clinical symptoms, severity and responsiveness to treatment, and is often accompanied by somatic comorbidities. The objective of this study was to identify and characterize subgroups of patients with a first-time MDD diagnosis based on somatic drug utilization, incl...

Background: Previous studies show social inequality in tooth loss, but the underlying pathways are not well understood. The aim was to investigate the mediated proportion of sugary beverages (SBs) and diabetes and the association between educational level and tooth loss, and to investigate whether the indirect effect of SBs and diabetes varied bet...

Background and aims: Alcohol use disorders (AUD) have not been included in the priority groups for early vaccine against SARS-CoV-2. We aimed to determine adverse outcomes after SARS-CoV-2 infection among individuals with AUD and how this is modified by vaccination. Design: Registry-based cohort study. Setting: Denmark, 27 February 2020 until...

Aim: To investigate whether the effect of alcohol use disorder (AUD) on death by natural and unnatural causes, respectively, differs according to intelligence quotient (IQ) scores. Methods: We followed 654 955 Danish men, including 75 267 brothers, born between 1939 and 1959 from their 25th birthday, 1 January 1970, or date of conscription (whic...

Background Major Depressive Disorder (MDD) is a heterogenous brain disorder, with potentially multiple psychosocial and biological disease mechanisms. This is also a plausible explanation for why patients do not respond equally well to treatment with first- or second-line antidepressants, i.e., one-third to one-half of patients do not remit in resp...

Introduction: Major depressive disorder (MDD) is associated with suicide events and with increased healthcare resource utilization (HRU). The aim was to analyze the pattern of HRU prior to death by suicide or suicide attempt in patients with MDD using national registries. Methods: Danish adults with MDD, who died by suicide or had a first-time s...

Aims: Gamma oscillations (≈25-100 Hz) are believed to play an essential role in cognition, and aberrant gamma oscillations occur in brain aging and neurodegeneration. This study examined age-related changes in visually evoked gamma oscillations at two different time points 5 years apart and tested the hypothesis that the power of gamma oscillation...

Importance: Major depression (MD) aggregates within families, but how family history of MD confers risk of MD over the life course is unclear. Such knowledge is important to identify and prevent possible depressogenic effects of family environment. Objective: To examine the association between family MD history and risk of MD including associati...

Aims: To explore the relationships between adult offspring's socioeconomic resources and the development of stroke and survival after stroke among older adults in Denmark and Sweden. Methods: The study included 1,464,740 Swedes and 835,488 Danes who had turned 65 years old between 2000 and 2015. Multivariable Cox proportional hazard regression m...

Background: Case studies have linked SARS-CoV-2 infection to suicidal behaviour. However, conclusive evidence is lacking. Aims: To examine whether a history of SARS-CoV-2 infection or SARS-CoV-2-related hospital admission was associated with self-harm in the general population and in high-risk groups. Method: A cohort design was applied to nat...

Weighing risks and benefits of postmenopausal hormone therapy (HT) has proven a balancing act. We aimed to investigate the association between HT and mortality before and after the 2002 publication from the Women’s Health Initiative (WHI) study. This publication found that the risk of using HT outweighted the benefits, and thus it caused a marked r...

AimTo describe trends in and characteristics of sedative drug use from 2000 through 2019 in relation to the introduction of central regulations and new drugs.Methods In this descriptive study, we used individual prescription data on the entire Danish population from the Danish National Prescription Registry to calculate yearly incidence and prevale...

Hippocampal blood–brain barrier (BBB) permeability may increase in normal healthy ageing and contribute to neurodegenerative disease. To examine this hypothesis, we investigated the correlation between blood–brain barrier (BBB) permeability, regional brain volume, memory functions and health and lifestyle factors in The Metropolit 1953 Danish Male...

Objectives The purpose of the study was to investigate whether postpartum depression is associated with a risk of depression during perimenopause. Study design This is a Danish nationwide register-based cohort study of 270,613 individuals who were born in 1960–1968, who gave birth to a liveborn child recorded in the Medical Birth Register before t...

Aims Cardiovascular patients with low socioeconomic status and non-western ethnic background have worse prognostic outcomes. The aim of this nationwide study was first to address whether short-term effects of hospital-based outpatient cardiac rehabilitation (CR) are similar across educational level and ethnic background, and secondly to study wheth...

Importance: During menopause, the levels of estrogen and progesterone decrease and 60% to 70% of women experience menopausal symptoms, including mood disturbances. The latter might be prevented by hormone therapy (HT), yet some studies have suggested that use of HT might be associated with increased risk of depression. Objective: To examine whet...

Background A key clinical problem in psychiatry is predicting the diagnostic future of patients presenting with psychopathology for the first time. The objective of this study was to establish a comprehensive map of subsequent diagnoses after a first psychiatric hospital diagnosis. Methods Through the Danish National Patient Registry, we identifie...

The study aims to investigate the association of aspiration for future occupation, socioeconomic position, and intellectual abilities with risk of dual diagnosis, psychosis, substance use disorder (SUD) in later life, and to explore if social and intellectual disadvantage modify any effect of childhood aspirations on outcomes. The study included 71...

Objectives To investigate healthcare resource utilization (HRU) and associated costs by depression severity and year of diagnosis among patients with treatment-resistant depression (TRD) in Denmark. Methods Including all adult patients with a first-time hospital contact for major depressive disorder (MDD) in 1996–2015, TRD patients were defined at...

Objective: The aim of the study is to examine whether electroconvulsive therapy (ECT) was associated with the subsequent risk of being involved in a road traffic accident. Methods: A cohort of all 375,435 patients older than 18 years with their first psychiatric hospital contact between 2003 and 2017 in the Danish National Patient Registry was f...

Background Discontinuation of antipsychotic medication may be linked to high risk of relapse, hospitalization and mortality. This study investigated the use and discontinuation of antipsychotics in individuals with first-episode schizophrenia in relation to cohabitation, living with children, employment, hospital admission and death. Methods Danis...

Aims We examined the influence of comorbid sleep disorder on the association between type 2 diabetes (T2D) and risk of incident depression. Methods The study population (N = 232,489) was based on all individuals registered aged ≥40 years with a T2D diagnosis between January 1, 2000 to December 31, 2012 in the Danish National Diabetes Register and...

Background: Knowledge of the adverse problems related to SARS-CoV-2 infection in marginalised and deprived groups may help to prioritise more preventive efforts in these groups. We examined adverse outcomes associated with SARS-CoV-2 infection among vulnerable segments of society. Methods: Using health and administrative registers, a population-...

Purpose We explored if patients with treatment-resistant depression (TRD) go through different states of labor market affiliation during their course of illness before they return to work or obtain early retirement as compared to patients without TRD. Methods All adults between 18 and 58 years with a first-time hospital contact due to depression i...

Background: Social deprivation, psychiatric and medical disorders have been associated with increased risk of infection and severe COVID-19-related health problems. We aimed to study the rates of SARS-CoV-2 vaccination in these high-risk groups. Methods: Using health, vaccination, and administrative registers, we performed a population-based cohort...

Objective The effect of systemic hormone therapy (HT) on dementia risk is unclear. Our aim was to investigate the association between HT and dementia. Study design This register-based study consists of a nested case-control study and a co-twin control design, which controls for familial confounding, including shared genetics. Main outcome measure...

Background and aims Large social disparities in the occurrence of cardiovascular disease (CVD) have been documented but the underlying biological mechanisms are largely unknown. We investigated a panel of biomarkers linked to CVD to improve our understanding and quantify the biological pathways in socioeconomic disparity in CVD and their mediation...

Background: Benzodiazepines, Z-drugs, pregabalin, and melatonin (BZPMs) have been associated with a higher risk of traffic accidents, but the evidence is inconsistent, and lacking for newer drugs. Aim: To examine the association of BZPMs with risk of traffic accidents. Methods: All Danish adults (n = 3,823,588) were followed for redeemed presc...

Objective Diabetes type 2 is associated with depression, but the impact of antidiabetic drugs is not clear. The objective was to analyze the association between diabetes type 2, antidiabetic drugs, and depression. Methods This register-based study included 116.699 patients with diabetes type 2 diagnosed from 2000-2012 and an age, gender, and munic...

Background Impaired fetal growth may increase vulnerability towards metabolic disturbances associated with some medications. We examined whether birth weight and ponderal index modify the association between psychotropic medication and type 2 diabetes among young adults with severe psychiatric diagnosis. Methods A total of 36,957 individuals born...

Background: Major depressive disorder (MDD) is a prevalent illness that causes significant suffering and expenses at the personal and societal levels. The disorder is subject to heterogeneity reflected by diverse clinical phenotypes and assorted responses to treatment. Research on MDD treatments have focused on one treatment at a time, however many...

Background The underlying disease mechanisms of Parkinson’s disease (PD) are still unknown and knowledge about risk and prognostic factors is sparse. Objective To examine the association between intelligence, education, body height, and body mass index (BMI) in young adulthood and risk of PD and subsequent survival. Methods In total, 656,751 men...

Background : Associations between depression and dementia could express a causal relationship, reverse causality or be explained by health-related factors. This study explores the association of depression and indicators of depression severity with subsequent risk of dementia while ensuring temporality and adjusting for important health-related fac...

The present study investigated the Danish secular trend of intelligence test scores among young men born between 1940 and 2000, as well as the possible associations of birth cohort changes in family size, nutrition, education, and intelligence test score variability with the increasing secular trend. The study population included all men born from...

Purpose This study aimed to investigate the time lag between onset and treatment (treatment delay) for alcohol use disorders (AUD) and associations between demographic factors and treatment delay for AUD. Methods The study included 6,584 men registered in the Copenhagen Alcohol Cohort, containing information on civil status, employment status, est...

Aims: Comorbid psychiatric disorders and the use of psychotropic medication are common among cardiac patients and have been found to increase the risk of mortality. The aims of this study were: (i) to describe the use of psychotropic medication among cardiac patients with and without symptoms of anxiety, (ii) to estimate the association between us...

Background and aim It is generally accepted that functional somatic disorders (FSDs) are a product of biological, psychological, and social factors. Social position might be part of this complex, but the literature on this issue is currently heterogeneous and inconsistent. The aim of the present study was – in a population-based cohort – to test th...

Objective: To examine whether electroconvulsive therapy (ECT) is associated with risk of mortality and acute somatic events in patients with or without somatic comorbidity. Methods: 174,495 patients with an affective disorder, of whom 41% had somatic comorbidity, were followed from 2005 through 2018 for ECT, mortality, and acute somatic outcomes...

Aims Cardiac patients with low socioeconomic status and non-western ethnic background have worse outcomes. The aim of this nationwide study was to determine whether the immediate effect of CR differs between groups defined by socioeconomic status and ethnic background, and whether disparity in the prognosis of cardiac patients is diminished by CR p...

Background and purpose A large unexplained social disparity in the occurrence of cardiovascular disease (CVD) has been documented. The precise mechanism behind these disparities is largely unknown. Biomarkers have improved our understanding of the pathophysiology of CVD. In this study we investigated differences in 184 biomarkers linked to CVD, wit...

Background: Major Depressive disorder (MDD) is a heterogeneous, multi-etiological disorder that is associated with chronic medical conditions and a high somatic treatment burden. A better understanding of the somatic diseases and treatment burden in MDD can be provided through a mapping of the somatic drug utilization patterns over time. The object...

Adolescence represents an important period in brain and mental development, which raises the question of whether measures of body size at entry into adult life influence the risk of developing mood disorders. We examined the association of BMI and height in a cohort of young men with risk of mood disorders throughout life. The study included 630,80...

Depression and cardiovascular disease (ischemic heart disease and stroke) are associated in a bidirectional manner. Their relatively high heritability has led to the hypothesis that this co-occurrence is related to shared familial and genetic factors; this study aims to test this hypothesis. We included 23,498 monozygotic and 39,540 same-sex dizygo...

Objective To explore the association of the number of TBIs and temporal associations with the subsequent risk of depression in the population. Methods National register-based cohort study on all individuals registered with TBI (ICD-10: S06, ICD-8: 85.0-85.5) from 1977 to 2015 in Denmark (n=494,216) and a sex- and age-matched reference population (...

Objective: The aim of the study was to investigate the separate and joint effects of household income and dental visits on tooth loss. Basic research design: Participants from the Social Inequality in Cancer Cohort (SIC) were followed in registers for household income (2000), dental visits (2002-2009) and tooth loss (2010-2016). Logistic regress...

Background : Patients with affective disorder seem to experience higher risks of several somatic diseases, but no studies have provided estimates of both absolute and relative risks for these diseases in the same population. Methods : A prospective cohort of all patients age ≥18 years old with a hospital contact with affective disorder between 199...

Objective We explored the comparability of anxiety measures from register- and survey-based data including analyses of prevalence and associations with selected psychiatric and somatic diseases. Methods We measured anxiety using Danish registers (hospital diagnosis and anxiolytic drug prescriptions), self-reports, symptom checklist (SCL) scores an...

Associations of educational level and intelligence with age at onset and age at treatment of alcohol use disorders (AUD) are sparsely investigated; however, knowledge about these associations is important for an enhanced understanding of AUD. This study aimed to examine three measures of timing of AUD: estimated age at onset of alcohol problems, ag...

Objective : To describe treatment patterns in patients with treatment-resistant depression (TRD) and major depressive disorder (MDD) stratified by depression severity and year of diagnosis. Patterns of treatment were also compared to country-specific guidelines. Methods : All adults registered first time with a hospital contact due to MDD from 199...

Aims: To assess the association between past level of physical activity (PA) and risk for death during the acute phase of myocardial infarction (MI) in a pooled analysis of cohort studies. Methods and results: European cohorts including participants with a baseline assessment of PA, conventional cardiovascular (CV) risk factors, and available fo...

Objective Treatment-resistant depression (TRD) has been associated with higher mortality and risk of suicide, but this has mainly been showed in few studies which did not include self-harm. The aim was to investigate the association of TRD with all-cause mortality, suicide and self-harm in a nationwide cohort of patients with major depression and e...