Adverse Childhood Experiences and Adult Mental Health Outcomes.

Importance: Exposure to adverse childhood experiences (ACEs) has consistently been associated with multiple negative mental health outcomes extending into adulthood. However, given that ACEs and psychiatric disorders cluster within families, it remains to be comprehensively assessed to what extent familial confounding contributes to associations between ACEs and clinically confirmed adult psychiatric disorders. Objective: To investigate whether associations between ACEs and adult mental health outcomes remain after adjusting for familial (genetic and environmental) confounding. Design, Setting, and Participants: This Swedish twin cohort study used a discordant twin pair design based on monozygotic (MZ) and dizygotic (DZ) twins. A total of 25 252 adult twins (aged 18-47 years) from the Swedish Twin Registry born between 1959 and 1998 were followed up from age 19 years until 2016, with a maximum follow-up time of 39 years. Data were analyzed from April 2022 to November 2023. Exposures: A total of 7 ACEs, including family violence, emotional abuse or neglect, physical neglect, physical abuse, sexual abuse, rape, and hate crime, were assessed with items from the Life Stressor Checklist-Revised in a web-based survey. Main Outcomes and Measures: Adult (ages >18 years) clinical diagnosis of psychiatric disorders (ie, depressive, anxiety, alcohol or drug misuse, or stress-related disorders) were obtained from the Swedish National Patient Register. Results: Of 25 252 twins included in the study (15 038 female [59.6%]; mean [SD] age at ACE assessment, 29.9 [8.7] years), 9751 individuals (38.6%) reported exposure to at least 1 ACE. A greater number of ACEs was associated with increased odds of any psychiatric disorder in the full cohort (odds ratio [OR] per additional ACE, 1.52; 95% CI, 1.48-1.57). The association remained but ORs per additional ACE were attenuated in DZ (1.29; 95% CI, 1.14-1.47) and MZ (1.20; 95% CI, 1.02-1.40) twin pairs. Individuals who were exposed to sexual abuse compared with those who were not exposed had increased odds of any clinically confirmed psychiatric disorder in all comparisons: full cohort (OR, 3.09; 95% CI, 2.68-3.56), DZ twin pairs (OR, 2.10; 95% CI, 1.33-3.32), and MZ twin pairs (1.80; 95% CI, 1.04-3.11). Conclusions and relevance: This study found that associations between ACEs and adult mental health outcomes remained after controlling for shared genetic and environmental factors, which was particularly evident after multiple ACEs or sexual abuse. These findings suggest that targeted interventions may be associated with reduced risks of future psychopathology.

Perinatal Depression and Risk of Suicidal Behavior.

Importance: Suicidal ideation is common among women with perinatal depression (PND). However, prospective data are limited on the risk, particularly long-term risk, of suicidal behavior (suicide attempt and completed suicide) among women with perinatal depression. Objective: To examine the association between PND and risk of short- and long-term suicidal behavior. Design, Setting, and Participants: A nationwide population-matched cohort study was conducted in Sweden including 86 551 women with PND from 2001 to 2017 and 865 510 unaffected women individually matched on age and calendar year at delivery. Sibling comparison was used to account for familial confounding. Data were analyzed from January 2022 to November 2023. Exposure: PND was identified through depression diagnosis or filled prescriptions of antidepressants from pregnancy to 1 year post partum in registers. Main Outcomes and Measures: All women were followed up for the first event of suicidal behavior recorded in registers. Hazard ratios (HR) of suicidal behavior were estimated using time-to-event analysis. Results: Women with PND (86 551 participants) received a diagnosis at a mean (SD) age of 30.67 (5.23) years. During a median (IQR) follow-up of 6.91 (3.62-10.88) years, 3604 events of suicidal behavior (incidence rate [IR], 5.62 per 1000 person-years) were identified among women with PND and 6445 (IR, 1.01 per 1000 person-years) among population-unaffected women. Women with PND had an elevated risk of suicidal behavior when compared with matched unaffected women (HR, 3.15; 95% CI, 2.97-3.35). Comparable, albeit somewhat attenuated, associations were yielded when comparing PND women with their PND-free sisters (HR, 2.75; 95% CI, 2.10-3.61). In the population-matched cohort, the association was greater for postnatal depression and among women without a history of psychiatric disorders. The excess risk was pronounced during the first year after diagnosis (HR, 7.20; 95% CI, 6.07-8.54), yet remained statistically significant during 5 to 18 years of follow-up (HR, 2.34; 95% CI, 2.12-2.57). Conclusions and Relevance: In this nationwide cohort study, women with PND were at an increased risk of suicidal behavior, particularly within the first year after diagnosis with persistent risk elevations throughout the 18 years of follow-up, highlighting the need for vigilant clinical monitoring of this vulnerable group.

Trends of perceived disruption in healthcare services during the pandemic: findings from the COVID-19 National Resilience Cohort in Iceland.

BACKGROUND: Coronavirus disease 2019 (COVID-19) caused major disruptions in healthcare services worldwide. Yet, little is known about the association between perceived disruption in healthcare services and socio-demographic factors, pre-existing health conditions as well as concurrent physical and psychological symptoms. METHODS: Leveraging data from the Icelandic COVID-19 National Resilience Cohort, we performed a repeated measure analysis among 15 754 participants who responded to the question on perceived disruption in healthcare services from December 2020 to July 2021, to explore its association with socio-demographic factors, health indicators and conditions. Furthermore, we performed a longitudinal analysis among 7848 participants with two repeated measures to explore the association between timing and duration of perceived disruption in healthcare services and changes in depression, anxiety, sleep quality and somatic symptoms. RESULTS: The prevalence of perceived disruption in healthcare services slightly decreased over time (P < 0.01). Perceived disruption in healthcare services was more prevalent among individuals with pre-existing health conditions, i.e. history of psychiatric disorders (prevalence ratio = 1.59, 95% confidence interval 1.48-1.72) and chronic somatic conditions [1.40 (1.30-1.52)]. However, no increase in the prevalence of perceived disruption in healthcare services was observed among individuals diagnosed with COVID-19 [0.99 (0.84-1.18)]. Moreover, we found that emerging perceived disruption in healthcare services was associated with an increase in symptoms of mental illness during the pandemic (ßs 0.06-0.68). CONCLUSIONS: A disruption in healthcare services during the COVID-19 pandemic was reported by vulnerable groups, while the Icelandic healthcare system managed to maintain accessible services to individuals with COVID-19.

COVID-19 illness severity and 2-year prevalence of physical symptoms: an observational study in Iceland, Sweden, Norway and Denmark.

Background: Although the persistence of physical symptoms after SARS-CoV-2 infection is a major public health concern, evidence from large observational studies beyond one year post diagnosis remain scarce. We aimed to assess the prevalence of physical symptoms in relation to acute illness severity up to more than 2-years after diagnosis of COVID-19. Methods: This multinational study included 64,880 adult participants from Iceland, Sweden, Denmark, and Norway with self-reported data on COVID-19 and physical symptoms from April 2020 to August 2022. We compared the prevalence of 15 physical symptoms, measured by the Patient Health Questionnaire (PHQ-15), among individuals with or without a confirmed COVID-19 diagnosis, by acute illness severity, and by time since diagnosis. We additionally assessed the change in symptoms in a subset of Swedish adults with repeated measures, before and after COVID-19 diagnosis. Findings: During up to 27 months of follow-up, 34.5% participants (22,382/64,880) were diagnosed with COVID-19. Individuals who were diagnosed with COVID-19, compared to those not diagnosed, had an overall 37% higher prevalence of severe physical symptom burden (PHQ-15 score ≥15, adjusted prevalence ratio [PR] 1.37 [95% confidence interval [CI] 1.23-1.52]). The prevalence was associated with acute COVID-19 severity: individuals bedridden for seven days or longer presented with the highest prevalence (PR 2.25 [1.85-2.74]), while individuals never bedridden presented with similar prevalence as individuals not diagnosed with COVID-19 (PR 0.92 [0.68-1.24]). The prevalence was statistically significantly elevated among individuals diagnosed with COVID-19 for eight of the fifteen measured symptoms: shortness of breath, chest pain, dizziness, heart racing, headaches, low energy/fatigue, trouble sleeping, and back pain. The analysis of repeated measurements rendered similar results as the main analysis. Interpretation: These data suggest an elevated prevalence of some, but not all, physical symptoms during up to more than 2 years after diagnosis of COVID-19, particularly among individuals suffering a severe acute illness, highlighting the importance of continued monitoring and alleviation of these targeted core symptoms. Funding: This work was mainly supported by grants from NordForsk (COVIDMENT, grant number 105668 and 138929) and Horizon 2020 (CoMorMent, 847776). See Acknowledgements for further details on funding.

Elevated symptoms of depression and anxiety among family members and friends of critically ill COVID-19 patients - an observational study of five cohorts across four countries.

Background: Little is known regarding the mental health impact of having a significant person (family member and/or close friend) with COVID-19 of different severity. Methods: The study included five prospective cohorts from four countries (Iceland, Norway, Sweden, and the UK) with self-reported data on COVID-19 and symptoms of depression and anxiety during March 2020-March 2022. We calculated prevalence ratios (PR) of depression and anxiety in relation to having a significant person with COVID-19 and performed a longitudinal analysis in the Swedish cohort to describe temporal patterns. Findings: 162,237 and 168,783 individuals were included in the analysis of depression and anxiety, respectively, of whom 24,718 and 27,003 reported a significant person with COVID-19. Overall, the PR was 1.07 (95% CI: 1.05-1.10) for depression and 1.08 (95% CI: 1.03-1.13) for anxiety in relation to having a significant person with COVID-19. The respective PRs for depression and anxiety were 1.15 (95% CI: 1.08-1.23) and 1.24 (95% CI: 1.14-1.34) if the patient was hospitalized, 1.42 (95% CI: 1.27-1.57) and 1.45 (95% CI: 1.31-1.60) if the patient was ICU-admitted, and 1.34 (95% CI: 1.22-1.46) and 1.36 (95% CI: 1.22-1.51) if the patient died. Individuals with a significant person with hospitalized, ICU-admitted, or fatal COVID-19 showed elevated prevalence of depression and anxiety during the entire year after the COVID-19 diagnosis. Interpretation: Family members and close friends of critically ill COVID-19 patients show persistently elevated prevalence of depressive and anxiety symptoms. Funding: This study was primarily supported by NordForsk (COVIDMENT, 105668) and Horizon 2020 (CoMorMent, 847776).

Psychiatric comorbidities in women with cardiometabolic conditions with and without ADHD: a population-based study.

BACKGROUND: Leveraging a large nationwide study of Icelandic women, we aimed to narrow the evidence gap around female attention-deficit/hyperactivity disorder (ADHD) and cardiometabolic comorbidities by determining the prevalence of obesity, hypertension, type 2 diabetes, and cardiovascular diseases among women with ADHD and examine the association between cardiometabolic conditions and co-occurring ADHD with anxiety and mood disorders, alcoholism/substance use disorder (SUD), self-harm, and suicide attempts. METHODS: We conducted a cross-sectional analysis of the nationwide, all-female, population-based SAGA Cohort Study (n = 26,668). To ascertain diagnoses and symptoms, we used self-reported history of ADHD diagnoses, selected cardiometabolic conditions and psychiatric disorders, and measured current depressive, anxiety, and PTSD symptoms through appropriate questionnaires (PHQ-9, GAD-7, and PCL-5). We calculated age-adjusted prevalences of cardiometabolic conditions by women's ADHD status and estimated adjusted prevalence ratios (PR) and 95% confidence intervals (CI), using modified Poisson regression models. Similarly, we assessed the association of cardiometabolic conditions and co-occurring ADHD with current psychiatric symptoms and psychiatric disorders, using adjusted PRs and 95% CIs. RESULTS: We identified 2299 (8.6%) women with a history of ADHD diagnosis. The age-adjusted prevalence of having at least one cardiometabolic condition was higher among women with ADHD (49.5%) than those without (41.7%), (PR = 1.19, 95% CI 1.14-1.25), with higher prevalence of all measured cardiometabolic conditions (myocardial infarctions (PR = 2.53, 95% CI 1.83--3.49), type 2 diabetes (PR = 2.08, 95% CI 1.66-2.61), hypertension (PR = 1.23, 95% CI 1.12-1.34), and obesity (PR = 1.18, 95% CI 1.11-1.25)). Women with cardiometabolic conditions and co-occurring ADHD had, compared with those without ADHD, substantially increased prevalence of (a) all measured mood and anxiety disorders, e.g., depression (PR = 2.38, 95% CI 2.19-2.58), bipolar disorder (PR = 4.81, 95% CI 3.65-6.35), posttraumatic stress disorder (PR = 2.78, 95% CI 2.52-3.07), social phobia (PR = 2.96, 95% CI 2.64-3.32); (b) moderate/severe depressive, anxiety, and PTSD symptoms with PR = 1.76 (95% CI 1.67-1.85), PR = 1.97 (95% CI 1.82-2.12), and PR = 2.01 (95% CI 1.88-2.15), respectively; (c) alcoholism/SUD, PR = 4.79 (95% CI 3.90-5.89); and (d) self-harm, PR = 1.47 (95% CI 1.29-1.67) and suicide attempts, PR = 2.37 (95% CI 2.05-2.73). CONCLUSIONS: ADHD is overrepresented among women with cardiometabolic conditions and contributes substantially to other psychiatric comorbidities among women with cardiometabolic conditions.

Contact with primary care physicians among adults with pre-existing common mental health problems during the COVID-19 pandemic: a registry-based study from Norway.

BACKGROUND: During the COVID-19 pandemic, individuals with pre-existing mental health problems may have experienced additional stress, which could worsen symptoms or trigger relapse. Thus, this study aimed to investigate if the number of consultations with general practitioners (GPs) among individuals with a pre-existing common mental health problem during the pandemic differed from pre-pandemic years. METHODS: Data on consultations with GPs among 18-65-year-olds registered with common mental health problems in 2017-2021 were retrieved from the Norwegian Control and Payment of Health Reimbursements Database. Based on data from the pre-pandemic years (2017-2019), we predicted the number of consultations per week for depression, anxiety disorder, phobia/obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), and eating disorders during the pandemic (March 2020-December 2021) among individuals with pre-existing mental health problems. The forecasted and observed trends in GP consultations per week during the pandemic were stratified by diagnosis, gender, and age groups. RESULTS: The observed number of consultations for anxiety disorder, PTSD, and eating disorders were significantly higher than forecasted during extended periods of the two pandemic years. The differences were largest for PTSD (on average 37% higher in men and 47% higher in women during the pandemic), and for eating disorders among women (on average 87% higher during the pandemic). There were only minor differences between the predicted and observed number of consultations for depression and phobia/OCD. CONCLUSIONS: During the pandemic, individuals with a recent history of mental health problems were more likely to seek help for anxiety disorder, PTSD, and eating disorders, as compared to pre-pandemic years.

Evaluation of Maternal Infection During Pregnancy and Childhood Leukemia Among Offspring in Denmark.

Importance: Maternal infection is common during pregnancy and is an important potential cause of fetal genetic and immunological abnormalities. Maternal infection has been reported to be associated with childhood leukemia in previous case-control or small cohort studies. Objective: To evaluate the association of maternal infection during pregnancy with childhood leukemia among offspring in a large study. Design, Setting, and Participants: This population-based cohort study used data from 7 Danish national registries (including the Danish Medical Birth Register, the Danish National Patient Registry, the Danish National Cancer Registry, and others) for all live births in Denmark between 1978 and 2015. Swedish registry data for all live births between 1988 and 2014 were used to validate the findings for the Danish cohort. Data were analyzed from December 2019 to December 2021. Exposures: Maternal infection during pregnancy categorized by anatomic locations identified from the Danish National Patient Registry. Main Outcomes and Measures: The primary outcome was any leukemia; secondary outcomes were acute lymphoid leukemia (ALL) and acute myeloid leukemia (AML). Offspring childhood leukemia was identified in the Danish National Cancer Registry. Associations were first assessed in the whole cohort using Cox proportional hazards regression models, adjusted for potential confounders. A sibling analysis was performed to account for unmeasured familial confounding. Results: This study included 2 222 797 children, 51.3% of whom were boys. During the approximately 27 million person-years of follow-up (mean [SD], 12.0 [4.6] years per person), 1307 children were diagnosed with leukemia (ALL, 1050; AML, 165; or other, 92). Children born to mothers with infection during pregnancy had a 35% increased risk of leukemia (adjusted hazard ratio [HR], 1.35 [95% CI, 1.04-1.77]) compared with offspring of mothers without infection. Maternal genital and urinary tract infections were associated with a 142% and 65% increased risk of childhood leukemia, with HRs of 2.42 (95% CI, 1.50-3.92) and 1.65 (95% CI, 1.15-2.36), respectively. No association was observed for respiratory tract, digestive, or other infections. The sibling analysis showed comparable estimates to the whole-cohort analysis. The association patterns for ALL and AML were similar to that for any leukemia. No association was observed for maternal infection and brain tumors, lymphoma, or other childhood cancers. Conclusions and Relevance: In this cohort study of approximately 2.2 million children, maternal genitourinary tract infection during pregnancy was associated with childhood leukemia among offspring. If confirmed in future studies, our findings may have implications for understanding the etiology and developing preventive measures for childhood leukemia.

Association between Adverse Childhood Experiences and Multiple Sclerosis in Icelandic Women-A Population-Based Cohort Study.

BACKGROUND: A growing literature, mostly based on selected populations, indicates that traumas may be associated with autoimmune diseases, yet few studies exist on adverse childhood experiences (ACEs) and multiple sclerosis (MS) in the general population. OBJECTIVE: We assessed cross-sectional associations between self-reported ACEs and MS among Icelandic women in the population-based Stress-And-Gene-Analysis (SAGA) cohort. METHODS: Participants (n = 27,870; mean age 44.9 years) answered a web-based survey that included the ACE-International Questionnaire and a question about MS diagnosis. Log-linear Poisson regression models estimated MS prevalence ratios and 95% confidence intervals for ACEs adjusted for covariates. RESULTS: 214 women reported having been diagnosed with MS (crude prevalence = 7.7 per 1000). Compared to women without MS, women with MS reported more fatigue, body pain and bladder problems. The average cumulative number of ACEs was 2.1. After adjustment for age, education, childhood deprivation, smoking and depressive symptoms, MS prevalence did not increase with increasing ACEs exposure (PR = 1.00, 95% CI = 0.92, 1.09). Thirteen ACE categories, including abuse, neglect, household dysfunction and violence were not individually or independently associated with MS. CONCLUSION: Limited by self-reported data and cross-sectional design, results do not consistently support associations between ACEs in the development of MS among adult Icelandic women.

Risk factors for workplace sexual harassment and violence among a national cohort of women in Iceland: a cross-sectional study.

BACKGROUND: Sexual harassment and violence in the workplace are a serious public health concern for women worldwide with substantial costs due to sick leave and personnel turnover. Yet little is known about the prevalence of sexual harassment and violence at a population level, especially across work sectors. The aim of this study was to investigate the prevalence of workplace sexual harassment and violence by demographic factors and work sectors among Icelandic women. METHODS: For this cross-sectional study we analysed nationally representative, de-identified individual-level data from women who had responded to an online survey item about self-labelled current and lifetime workplace sexual harassment or violence as part of the Stress and Gene Analysis (SAGA) study, a cross-sectional nationally representative study done from March 1, 2018, to July 1, 2019. Eligible participants were women who resided in Iceland, were aged between 18 and 69 years, spoke Icelandic, and had a registered address from the Icelandic Population Register or a telephone number from the online 1819 service. We used binomial and Poisson regression analysis to study the cross-sectional association between workplace sexual harassment and violence and demographic factors (eg, age, sexual orientation, and education) and factors relating to the workplace (eg, work schedule), across works sectors. FINDINGS: Of 113 814 eligible women, 104 197 were invited to complete the online survey, of whom 30 403 women responded and were included in the SAGA cohort. 15 799 women answered the item about exposure to workplace sexual harassment or violence. 11 286 [71·4%] of 15 799 women answered the question about sexual orientation that were included in the survey from June, 2018. 5291 (33·5%) of 15 799 of participants reported having experienced workplace sexual harassment or violence during their lifetime, and 1178 (7·5%) in their current workplace. Such exposure in the current workplace was most common among women who were young (age 18-24 years: prevalence ratio [PR] 3·89 [95% CI 2·66-5·71]; age 25-34 years: 3·66 [2·53-5·31]), single (1·27 [1·12-1·43]), and worked shifts (2·32 [2·02-2·67]), with the highest prevalence rates observed among women in work sectors of public figures (15·67 [9·34-25·12]), tourism (15·01 [11·01-20·13]), and the legal system and security (13·56 [7·00-24·66]). Lifetime exposure to workplace sexual harassment or violence was more common among women who belonged to sexual minorities than among heterosexual women (PR 1·35 [1·24-1·46]). INTERPRETATION: Lifetime exposure to workplace sexual harassment or violence seems common among women in a Nordic welfare state. These findings provide nuanced targets for prevention and for public policies aimed at promoting women's safety in the work environment. FUNDING: Icelandic Gender Equality Fund, European Research Council, and Icelandic Centre for Research.

Sleep disturbances among women in a Subarctic region: a nationwide study.

STUDY OBJECTIVES: To date, few studies have assessed sleep problems among women residing in Subarctic regions. Therefore, the aim of this large-scale population-based study was to assess the prevalence of severe sleep problems and associated factors among Icelandic women, living at 63-66°N. METHODS: Participants were 29 681 women (18-69 years old) who took part in the Icelandic Stress-And-Gene-Analysis study in 2018-2019. Background information, health-related behavior, and mental health symptoms were assessed with an online questionnaire. The Pittsburgh Sleep Quality Index (PSQI) was used to assess severe sleep problems during the past month. Adjusting for age, marital status, number of children, education, personal income, work schedule, region, and response period, we used modified Poisson log-linear models to obtain prevalence ratios (PRs) with 95% confidence intervals (CIs). RESULTS: Overall, 24.2% of women reported severe sleep problems (PSQI >10). Women responding in the winter presented with an overall higher prevalence of severe sleep problems, compared to those responding in the summer (PR 1.21; 95% CI, 1.15 to 1.28). Severe sleep problems were more prevalent among young and late-midlife women, those who were single, had children, socio-economic challenges, worked shifts, and flexible hours. Furthermore, obesity, suboptimal health behaviors, excessive screen time, and mental health problems were associated with severe sleep problems. CONCLUSION: Severe sleep problems are more common among women in Subarctic regions than elsewhere, particularly during winter. These findings motivate the development of preventive strategies and interventions for women in the Subarctic who suffer from sleep problems.

Association of Maternal Autoimmune Diseases With Risk of Mental Disorders in Offspring in Denmark.

Importance: Maternal immune activation during pregnancy is associated with increased risks of several mental disorders in offspring during childhood, but little is known about how maternal autoimmune diseases during pregnancy are associated with mental health in offspring during and after childhood. Objective: To investigate the association between maternal autoimmune diseases before childbirth and risk of mental disorders among offspring up to early adulthood. Design, Setting, and Participants: This population-based nationwide cohort study used data from Danish national registers on singletons born in Denmark from 1978 to 2015 with up to 38 years of follow-up. Data analyses were conducted from March 1, 2020, through September 30, 2021. Exposures: Maternal autoimmune disease diagnosed before or during pregnancy according to the Danish National Patient Register. Main Outcomes and Measures: The main outcome was mental disorders, defined by hospital diagnoses, in offspring. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% CIs for mental disorders. Results: Of the 2 254 234 singleton infants included in the study (median age, 16.7 years [IQR, 10.5-21.7 years]; 51.28% male), 2.26% were born to mothers with autoimmune diseases before childbirth. Exposed participants had an increased risk of overall mental disorders compared with their unexposed counterparts (HR, 1.16; 95% CI, 1.13-1.19; incidence, 9.38 vs 7.91 per 1000 person-years). Increased risks of overall mental disorders in offspring were seen in different age groups for type 1 diabetes (1-5 years: HR, 1.35 [95% CI, 1.17-1.57]; 6-18 years: HR, 1.24 [95% CI, 1.15-1.33]; >18 years: HR, 1.19 [95% CI, 1.09-1.30]) and rheumatoid arthritis (1-5 years: HR, 1.42 [95% CI, 1.16-1.74]; 6-18 years: HR, 1.19 [95% CI, 1.05-1.36]; >18 years: HR, 1.28 [95% CI, 1.02-1.60]). Regarding specific mental disorders, increased risk after exposure to any maternal autoimmune disorder was observed for organic disorders (HR, 1.54; 95% CI, 1.21-1.94), schizophrenia (HR, 1.35; 95% CI, 1.21-1.51), obsessive-compulsive disorder (HR, 1.42; 95% CI, 1.24-1.63), mood disorders (HR, 1.12; 95% CI, 1.04-1.21), and a series of neurodevelopmental disorders (eg, childhood autism [HR, 1.21; 95% CI, 1.08-1.36] and attention-deficit/hyperactivity disorder [HR, 1.19; 95% CI, 1.12-1.26]). Conclusions and Relevance: In this cohort study in Denmark, prenatal exposure to maternal autoimmune diseases was associated with increased risks of overall and type-specific mental disorders in offspring. Maternal type 1 diabetes and rheumatoid arthritis during pregnancy were associated with offspring's mental health up to early adulthood. Individuals prenatally exposed to autoimmune disease may benefit from long-term surveillance for mental disorders.

Acute COVID-19 severity and mental health morbidity trajectories in patient populations of six nations: an observational study.

BACKGROUND: Long-term mental and physical health consequences of COVID-19 (long COVID) are a persistent public health concern. Little is still known about the long-term mental health of non-hospitalised patients with COVID-19 with varying illness severities. Our aim was to assess the prevalence of adverse mental health symptoms among individuals diagnosed with COVID-19 in the general population by acute infection severity up to 16 months after diagnosis. METHODS: This observational follow-up study included seven prospectively planned cohorts across six countries (Denmark, Estonia, Iceland, Norway, Sweden, and the UK). Participants were recruited from March 27, 2020, to Aug 13, 2021. Individuals aged 18 years or older were eligible to participate. In a cross-sectional analysis, we contrasted symptom prevalence of depression, anxiety, COVID-19-related distress, and poor sleep quality (screened with validated mental health instruments) among individuals with and without a diagnosis of COVID-19 at entry, 0-16 months from diagnosis. In a cohort analysis, we further used repeated measures to estimate the change in mental health symptoms before and after COVID-19 diagnosis. FINDINGS: The analytical cohort consisted of 247 249 individuals, 9979 (4·0%) of whom were diagnosed with COVID-19 during the study period. Mean follow-up was 5·65 months (SD 4·26). Participants diagnosed with COVID-19 presented overall with a higher prevalence of symptoms of depression (prevalence ratio [PR] 1·18 [95% CI 1·03-1·36]) and poorer sleep quality (1·13 [1·03-1·24]) but not symptoms of anxiety (0·97 [0·91-1·03]) or COVID-19-related distress (1·05 [0·93-1·20]) compared with individuals without a COVID-19 diagnosis. Although the prevalence of depression and COVID-19-related distress attenuated with time, individuals diagnosed with COVID-19 but never bedridden due to their illness were consistently at lower risk of depression (PR 0·83 [95% CI 0·75-0·91]) and anxiety (0·77 [0·63-0·94]) than those not diagnosed with COVID-19, whereas patients who were bedridden for more than 7 days were persistently at higher risk of symptoms of depression (PR 1·61 [95% CI 1·27-2·05]) and anxiety (1·43 [1·26-1·63]) than those not diagnosed throughout the study period. INTERPRETATION: Severe acute COVID-19 illness-indicated by extended time bedridden-is associated with long-term mental morbidity among recovering individuals in the general population. These findings call for increased vigilance of adverse mental health development among patients with a severe acute disease phase of COVID-19. FUNDING: Nordforsk, Horizon2020, Wellcome Trust, and Estonian Research Council.

Adverse childhood experiences and resilience among adult women: A population-based study.

Background: Adverse childhood experiences (ACEs) have consistently been associated with elevated risk of multiple adverse health outcomes, yet their contribution to coping ability and psychiatric resilience in adulthood is unclear. Methods: Cross-sectional data were derived from the ongoing Stress-And-Gene-Analysis cohort, representing 30% of the Icelandic nationwide female population, 18-69 years. Participants in the current study were 26,198 women with data on 13 ACEs measured with the ACE-International Questionnaire. Self-reported coping ability was measured with the Connor-Davidson Resilience Scale and psychiatric resilience was operationalized as absence of psychiatric morbidity. Generalized linear regression assuming normal or Poisson distribution were used to assess the associations of ACEs with coping ability and psychiatric resilience controlling for multiple confounders. Results: Number of ACEs was inversely associated with adult resilience in a dose-dependent manner; every 1SD unit increase in ACE scores was associated with both lower levels of coping ability (ß = -0.14; 95% CI-0.15,-0.13) and lower psychiatric resilience (ß = -0.28; 95% CI-0.29,-0.27) in adulthood. Compared to women with 0 ACEs, women with ≥5 ACEs had 36% lower prevalence of high coping ability (PR = 0.64, 95% CI 0.59,0.70) and 58% lower prevalence of high psychiatric resilience (PR = 0.42; 95% CI 0.39,0.45). Specific ACEs including emotional neglect, bullying, sexual abuse and mental illness of household member were consistently associated with reduced adult resilience. We observed only slightly attenuated associations after controlling for adult socioeconomic factors and social support in adulthood. Conclusions: Cumulative ACE exposure is associated with lower adult resilience among women, independent of adult socioeconomic factors and social support, indicating that adult resilience may be largely determined in childhood. Funding: This work was supported by the European Research Council (Consolidator grant; UAV, grant number 726413), and the Icelandic Center for Research (Grant of excellence; UAV, grant number 163362-051). HBD was supported by a doctoral grant from the University of Iceland Research Fund.

Association between adverse childhood experiences and premenstrual disorders: a cross-sectional analysis of 11,973 women.

BACKGROUND: Childhood abuse and neglect have been associated with premenstrual disorders (PMDs), including premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD). However, the associations of other adverse childhood experiences (ACEs) and the cumulative number of ACEs with PMDs remain to be explored. METHODS: To evaluate the associations of the cumulative number and types of ACEs with PMDs, we conducted a cross-sectional analysis with a subsample of menstruating women within the Stress-And-Gene-Analysis (SAGA) cohort, assessed for PMDs and ACEs (N=11,973). The cumulative and individual exposure of 13 types of ACEs was evaluated by a modified ACE-International Questionnaire. A modified version of the Premenstrual Symptom Screening Tool was used to identify probable cases of PMDs, further sub-grouped into PMS and PMDD. Prevalence ratios (PRs) of PMDs in relation to varying ACEs were estimated using Poisson regression. RESULTS: At a mean age of 34.0 years (standard deviation (SD) 9.1), 3235 (27%) met the criteria of probable PMDs, including 2501 (21%) for PMS and 734 (6%) for PMDD. The number of ACEs was linearly associated with PMDs (fully-adjusted PR 1.12 per ACE, 95% CI 1.11-1.13). Specifically, the PR for PMDs was 2.46 (95% CI 2.21-2.74) for women with 4 or more ACEs compared with women with no ACEs. A stronger association was observed for probable PMDD compared to PMS (p for difference <0.001). The associations between ACEs and PMDs were stronger among women without PTSD, anxiety, or depression, and without childhood deprivation and were stronger among women a lower level of social support (p for interaction<0.001). All types of ACEs were positively associated with PMDs (PRs ranged from 1.11 to 1.51); the associations of sexual abuse, emotional neglect, family violence, mental illness of a household member, and peer and collective violence were independent of other ACEs. CONCLUSIONS: Our findings suggest that childhood adverse experiences are associated with PMDs in a dose-dependent manner. If confirmed by prospective data, our findings support the importance of early intervention for girls exposed to ACEs to minimize risks of PMDs and other morbidities in adulthood.

Perinatal mental health: how nordic data sources have contributed to existing evidence and future avenues to explore.

PURPOSE: Perinatal mental health disorders affect a significant number of women with debilitating and potentially life-threatening consequences. Researchers in Nordic countries have access to high quality, population-based data sources and the possibility to link data, and are thus uniquely positioned to fill current evidence gaps. We aimed to review how Nordic studies have contributed to existing evidence on perinatal mental health. METHODS: We summarized examples of published evidence on perinatal mental health derived from large population-based longitudinal and register-based data from Denmark, Finland, Iceland, Norway and Sweden. RESULTS: Nordic datasets, such as the Danish National Birth Cohort, the FinnBrain Birth Cohort Study, the Icelandic SAGA cohort, the Norwegian MoBa and ABC studies, as well as the Swedish BASIC and Mom2B studies facilitate the study of prevalence of perinatal mental disorders, and further provide opportunity to prospectively test etiological hypotheses, yielding comprehensive suggestions about the underlying causal mechanisms. The large sample size, extensive follow-up, multiple measurement points, large geographic coverage, biological sampling and the possibility to link data to national registries renders them unique. The use of novel approaches, such as the digital phenotyping data in the novel application-based Mom2B cohort recording even voice qualities and digital phenotyping, or the Danish study design paralleling a natural experiment are considered strengths of such research. CONCLUSIONS: Nordic data sources have contributed substantially to the existing evidence, and can guide future work focused on the study of background, genetic and environmental factors to ultimately define vulnerable groups at risk for psychiatric disorders following childbirth.

Prenatal Maternal Bereavement and Its Association With Intellectual Disability in the Offspring.

OBJECTIVE: This study aimed to examine the association of a mother's loss of a close relative before or during pregnancy with intellectual disability (ID) in the offspring. METHODS: We performed a nationwide population-based cohort study based on Danish national registries. All live-born singletons born in Denmark during the 1978-2016 period (n = 2,216,601) were followed up starting from birth to 38 years of age. Log-linear Poisson regression was used to estimate the association between maternal bereavement (the death of an older child, a partner, or a parent 1 year before or during pregnancy) and the risk of ID in the offspring. RESULTS: Maternal bereavement during or before pregnancy was associated with an increased risk of ID (incidence rate ratio [IRR] = 1.15; 95% confidence interval [CI] = 1.04-1.28). The risk of ID was increased by 27% when maternal bereavement occurred during pregnancy (IRR = 1.27; 95% CI = 1.08-1.49). When stratifying on the child's sex, we also observed an increased risk of ID associated with maternal bereavement during pregnancy both for male (IRR = 1.25; 95% CI = 1.02-1.53) and for female (IRR = 1.31; 95% CI = 1.02-1.69), respectively. The IRRs for unnatural death of a relative were also elevated (IRR = 1.22; 95% CI = 0.91-1.64) in general, although the difference was not statistically significant. CONCLUSIONS: Our findings suggest that prenatal stress due to maternal loss of a close relative may increase the risk of offspring's ID of both sexes, in particular when the loss happened during pregnancy.

Nordic Health Registry-Based Research: A Review of Health Care Systems and Key Registries.

The Nordic countries are Denmark, Finland, Iceland, Norway, and Sweden and comprise a total population of approximately 27 million. The countries provide unique opportunities for joint health registry-based research in large populations with long and complete follow-up, facilitated by shared features, such as the tax-funded and public health care systems, the similar population-based registries, and the personal identity number as unique identifier of all citizens. In this review, we provide an introduction to the health care systems, key registries, and how to navigate the practical and ethical aspects of setting up such studies. For each country, we provide an overview of population statistics and health care expenditures, and describe the operational and administrative organization of the health care system. The Nordic registries provide population-based, routine, and prospective data on individuals lives and health with virtually complete follow-up and exact censoring information. We briefly describe the total population registries, birth registries, patient registries, cancer registries, prescription registries, and causes of death registries with a focus on period of coverage, selected key variables, and potential limitations. Lastly, we discuss some practical and legal perspectives. The potential of joint research is not fully exploited, mainly due to legal and practical difficulties in, for example, cross-border sharing of data. Future tasks include clear and transparent legal pathways and a framework by which practical aspects are facilitated.

Mode of delivery was associated with transient changes in the metabolomic profile of neonates.

AIMS: To estimate potential differences in neonatal metabolomic profiles at birth and at the time of newborn screening by delivery mode. METHODS: A prospective study at Women's Clinic at Landspitali-The National University Hospital of Iceland. Women having normal vaginal birth or elective caesarean section from November 2013 to April 2014 were offered participation. Blood samples from mothers before birth and umbilical cord at birth were collected and amino acids and acylcarnitines measured by tandem mass spectrometry. Results from the Newborn screening programme in Iceland were collected. Amino acids and acylcarnitines from different samples were compared by delivery mode. RESULTS: Eighty three normal vaginal births and 32 elective caesarean sections were included. Mean differences at birth were higher for numerous amino acids, and some acylcarnitines in neonates born vaginally compared to elective caesarean section. Maternal blood samples and newborn screening results showed small differences that lost significance after correction for multiple testing. Many amino acids and some acylcarnitines were numerically higher in cord blood compared to maternal. Many amino acids and most acylcarnitines were numerically higher in newborn screening results compared to cord blood. CONCLUSION: We observed transient yet distinct differences in metabolomic profiles between neonates by delivery mode.

Mortality and major disease risk among migrants of the 1991-2001 Balkan wars to Sweden: A register-based cohort study.

BACKGROUND: In recent decades, millions of refugees and migrants have fled wars and sought asylum in Europe. The aim of this study was to quantify the risk of mortality and major diseases among migrants during the 1991-2001 Balkan wars to Sweden in comparison to other European migrants to Sweden during the same period. METHODS AND FINDINGS: We conducted a register-based cohort study of 104,770 migrants to Sweden from the former Yugoslavia during the Balkan wars and 147,430 migrants to Sweden from 24 other European countries during the same period (1991-2001). Inpatient and specialized outpatient diagnoses of cardiovascular disease (CVD), cancer, and psychiatric disorders were obtained from the Swedish National Patient Register and the Swedish Cancer Register, and mortality data from the Swedish Cause of Death Register. Adjusting for individual-level data on sociodemographic characteristics and emigration country smoking prevalence, we used Cox regressions to contrast risks of health outcomes for migrants of the Balkan wars and other European migrants. During an average of 12.26 years of follow-up, being a migrant of the Balkan wars was associated with an elevated risk of being diagnosed with CVD (HR 1.39, 95% CI 1.34-1.43, p < 0.001) and dying from CVD (HR 1.45, 95% CI 1.29-1.62, p < 0.001), as well as being diagnosed with cancer (HR 1.16, 95% CI 1.08-1.24, p < 0.001) and dying from cancer (HR 1.27, 95% CI 1.15-1.41, p < 0.001), compared to other European migrants. Being a migrant of the Balkan wars was also associated with a greater overall risk of being diagnosed with a psychiatric disorder (HR 1.19, 95% CI 1.14-1.23, p < 0.001), particularly post-traumatic stress disorder (HR 9.33, 95% CI 7.96-10.94, p < 0.001), while being associated with a reduced risk of suicide (HR 0.68, 95% CI 0.48-0.96, p = 0.030) and suicide attempt (HR 0.57, 95% CI 0.51-0.65, p < 0.001). Later time period of migration and not having any first-degree relatives in Sweden at the time of immigration were associated with greater increases in risk of CVD and psychiatric disorders. Limitations of the study included lack of individual-level information on health status and behaviors of migrants at the time of immigration. CONCLUSIONS: Our findings indicate that migrants of the Balkan wars faced considerably elevated risks of major diseases and mortality in their first decade in Sweden compared to other European migrants. War migrants without family members in Sweden or with more recent immigration may be particularly vulnerable to adverse health outcomes. Results underscore that persons displaced by war are a vulnerable group in need of long-term health surveillance for psychiatric disorders and somatic disease.