Unnur Valdimarsdóttir

Background: Neurodivergent youth and youth with pre‐existing psychiatric disorders may have faced additional challenges in navigating the demands and restrictions of the COVID‐19 pandemic. However, less is known about how mental health outcomes and psychiatric healthcare utilization differed across diagnostic groups and other youth‐related factors. This systematic review synthesizes evidence on mental health symptoms and psychiatric healthcare use among youth with pre‐existing conditions during the pandemic. Methods: We searched PubMed, Web of Science and additional sources for cross‐sectional and longitudinal studies with data collected between March 2020 and May 2023. Eligible studies included neurodivergent youth and/or youth with psychiatric disorders confirmed through clinician diagnosis or medical records prior to the pandemic. Given the clinical and methodological diversity of studies, findings were synthesized narratively. Results: Forty‐eight studies met the inclusion criteria. Mental health outcomes showed mixed patterns both across and within diagnostic groups, with individual studies reporting symptom increase, stability and improvements. Evidence on psychiatric healthcare utilization was more limited and suggested different patterns between service use and psychotropic medication use. Compared to boys, girls were more likely to experience COVID‐related distress and increases in psychiatric service use during the pandemic. Age‐related findings varied across developmental stages and outcome domains. Most studies ( n = 40; 83.3%) had a moderate overall risk of bias (RoB), while seven (14.6%) had a high overall RoB. Conclusion: Mental health outcomes among youth with pre‐existing conditions during the COVID‐19 pandemic varied both within and across diagnostic groups. Outcomes were also associated with individual, developmental, contextual and service‐related factors. These findings suggest the importance of considering such factors alongside diagnosis when identifying clinical needs and planning support during large‐scale societal disruptions. Evidence on psychiatric healthcare utilization remains limited. More methodologically robust research is needed to clarify mental health and healthcare‐use patterns during major public health emergencies.

Background: Young people not in employment, education, or training (NEET) are a major concern presenting extensive societal and personal costs. Adverse childhood experiences (ACEs) can have longstanding harmful effects on health, education and employment participation. This study examined if ACEs are associated with NEET status among young Icelandic women, and whether perceived coping ability and social support moderate this relationship. Methods: Using data from 6 101 women aged 18–29 in the Stress-And-Gene-Analysis cohort, NEET status was self-reported, ACEs were assessed with the ACE-International Questionnaire (13 items), current perceived coping ability with the Connor-Davidson Resilience Scale and social support with the Multidimensional Scale of Perceived Social Support. Logistic regression estimated associations between ACEs (total score, categorical score, and individual subtypes) and NEET status. Moderation by perceived coping ability and social support was assessed using interaction models, with effects evaluated on the absolute scale using predicted probabilities and differences in predicted NEET probability across ACE levels. Multiple imputation addressed missing data. Results: After adjustment for sociodemographic factors, ACEs were strongly associated with NEET in a dose-dependent manner. Compared with women having 0 ACEs, women with ≥ 5 ACEs had almost sixfold higher odds of NEET (OR 5.62 [95% CI 3.60–8.78]), and each additional ACE increased odds by 23% (OR 1.23 [1.18–1.29]). When examined separately, all ACE subtypes—especially emotional neglect, emotional abuse, mental illness in the household and bullying—were associated with NEET. Analyses of predictive probabilities indicated that the association between ACEs and NEET was stronger among women with low coping ability, whereas social support did not modify this association. Conclusions: ACEs are strongly associated with NEET status among young women with low coping ability exacerbating the association, while social support showed no modifying effect. This suggests deep-rooted impacts of childhood adversity may depend more on internal adaptive capacity than on external social resources, highlighting coping capacity as potential target for intervention.

Although cancer patients have a high burden of mental illness, it is less clear whether patients with mental illness experience a higher-than-expected cancer risk. This systematic review investigated the associations between a wide range of types of mental illness and subsequent cancer risk. Five electronic databases were searched for articles published from database initiation to October 24, 2024. Studies using nationwide Nordic register data to conduct a prospective analysis of the association between mental illness diagnosis and cancer incidence were included. When data from three or more countries were available for a given type of mental illness, random effects meta-analyses were performed; otherwise, narrative syntheses were conducted. A total of 7,767 non-duplicate articles were screened, of which 20 were included. Meta-analyses showed no association between schizophrenia diagnosis and overall cancer risk; however, a high level of heterogeneity was detected between studies. Individuals with schizophrenia appeared to have a higher risk of breast cancer (pooled standardized incidence ratio [SIR]: 1.28, 95% confidence interval [CI]: 1.08-1.52), and lower risks of rectal cancer (pooled SIR: 0.75, 95% CI: 0.59-0.95) and prostate cancer (pooled SIR: 0.53, 95% CI: 0.48-0.59), compared to individuals in the general population. A higher risk of overall cancer was observed for mood, anxiety, and stress-related disorders, as well as autism and intellectual disability, in multiple studies; however, the results differed by cancer types and sex. In summary, these findings suggest an altered risk of cancer among individuals with mental illness living in Nordic countries. Further research is needed to enable the development of targeted cancer prevention strategies to reduce mental health disparities in cancer protection.

Understanding whether and how shared genetic factors contribute to the comorbidity between stress-related disorders (SRDs) and cardiovascular disease (CVD) is important for integrated prevention and treatment, but current evidence remains limited. To address this gap, we integrated Swedish national registers (n = 4,123,631), UK Biobank (n = 502,291), and genome-wide association study summary statistics to explore shared genetic liability between SRDs and six CVD subtypes and to nominate pleiotropic loci, genes, and enriched pathways. Familial coaggregation analyses showed that the SRDs–CVD association attenuated with decreasing genetic relatedness among relatives, supporting the existence of shared genetic influences. Polygenic risk scores for SRDs significantly predicted a higher risk of any CVD and all subtypes (odds ratios = 1.05–1.09), and all SRDs–CVD pairs showed positive genetic correlations (rg = 0.09–0.35), whereas Mendelian randomization (MR) analyses did not support strong causal effects in either direction. Genome-wide cross-trait analyses identified 17 putative pleiotropic loci, and consensus-based gene mapping prioritized 16 putative pleiotropic genes. Enrichment analyses indicated that pleiotropic signals were enriched in processes related to hemostasis and coagulation, circulatory system development, and telomere maintenance. In validation analyses focusing on post-traumatic stress disorder (PTSD), we observed a similar pattern of genetic overlap with CVD and replicated a subset of loci, genes, and pathways. These findings support a genetic comorbidity framework in which shared genetic liability, largely driven by pleiotropic loci, contributes to the co-occurrence of SRDs and CVD and highlight candidate genes and biological processes for future experimental studies.

Background: Pre-existing psychiatric disorders have been associated with the severity of acute respiratory infections, including COVID-19, particularly in hospitalized populations. However, the underlying mechanisms, especially in community-based populations, remain unknown, limiting preparedness for future pandemics. We investigated the role of genetic liability for psychiatric disorders and related traits in COVID-19 and other respiratory infection severity among individuals reporting SARS-CoV-2 testing and available respiratory symptom data. Methods: We included population-based cohort data from Denmark, Estonia, Iceland, Norway, and the United Kingdom (N = 78,507; 62% female; 41% SARS-CoV-2-positive; May 2020—March 2023). Respiratory infection severity was defined by self-reported days bedridden and an eleven-symptom composite score during the acute illness phase. Polygenic scores (PGSs) for eight psychiatric disorders and the personality trait neuroticism indexed genetic liability. Meta-analysed estimates from stepwise-adjusted regression analyses controlling for education, lifestyle, and psychiatric and somatic diagnosis history were used to assess associations between PGSs and acute respiratory infection severity, stratified by COVID-19 status. Results: Higher genetic liability to insomnia, major depression (MD), and neuroticism was consistently associated with longer time bedridden (relative risk ratios per 1 SD change in PGS: 1.07–1.14, 95% confidence intervals [CIs]: 1.03–1.21) and more symptoms (incident rate ratios [IRRs]: 1.02–1.04, 95% CIs: 1.01–1.05) due to COVID-19. PGSs for insomnia, MD, neuroticism, anxiety disorder, bipolar disorder, and schizophrenia were also linked to higher non-COVID-19 symptom count (IRRs: 1.01–1.05, 95% CIs: 1.00–1.07). These associations remained robust after adjustment for lifestyle, education and medical comorbidities. Individuals in the highest MD PGS decile reported 20% more symptoms in non-COVID-19 illness and 10% more in COVID-19 compared with the bottom decile. No consistent associations were detected with attention-deficit/hyperactivity disorder, alcohol dependence and post-traumatic stress disorder. No genetic link was observed with ischaemic heart disease or type 2 diabetes. Conclusions: Shared genetics may contribute to the link between psychiatric conditions and respiratory infection severity in community settings. Our results underscore the role of psychiatric genetic liability, beyond diagnosed psychiatric disorders, in contributing to both COVID-19 and other respiratory infection severity. These findings provide insights that may improve future risk stratification and public health strategies targeting respiratory viruses.

Background: Trauma-associated sleep disorder is a proposed sleep disorder characterized by trauma-related nightmares, hyperarousal during sleep, and disruptive nocturnal behaviors following exposure to a traumatic event. Sleep problems are common after trauma, yet little is known about their prevalence among women in the general population. We aimed to estimate the prevalence of trauma-associated sleep disturbances (TASD) and identify associated factors in a large nationally representative cohort. Methods: We used data from a population-based cohort of Icelandic women aged 18 to 69 years. Of the 30,403 women who provided informed consent, 27,938 women were included in the analysis. Participants completed assessments of trauma history, TASD, and other mental health outcomes. Past month TASD were identified using established symptom criteria. Prevalence ratios were estimated using modified Poisson regression adjusted for demographic, socioeconomic, behavioral, and trauma-related factors. Results: Here we show that 6.9% of women in the cohort report TASD. Prevalence was highest among young women and those exposed to physical or sexual violence. Experiencing the worst life stressor more than once and close temporal proximity to the worst life stressor was also associated with higher TASD prevalence. TASD are strongly associated with symptoms of posttraumatic stress disorder (PTSD), depression, anxiety, and general sleep problems. Conclusions: Results indicate that TASD affect a substantial number of women in the general population and are most prevalent among women exposed to interpersonal violence and among those with repeated or recent traumatic experiences. These findings underscore the importance of early identification of TASD and targeted interventions in healthcare.

Background: There is a need for scalable and simple interventions for trauma-exposed people. In this case series, we built on our previous case study and case series findings and further explored the use and potential effectiveness of a brief novel intervention to reduce the number of past intrusive memories of trauma. The imagery competing task intervention consists of a memory reminder and the visuospatial task Tetris played with mental rotation, targeting 1 intrusive memory at a time. Here, we test remote delivery of the intervention, including guidance from researchers without specialist mental health training, in a sample of women in Iceland with current intrusive memories from trauma. Objective: In a case series of trauma-exposed women, we aimed to explore whether this brief novel intervention reduces the number of established intrusive memories (primary outcome) and improves general functioning and symptom reduction in posttraumatic stress, depression, and anxiety (secondary outcomes). The acceptability of the intervention along with adaptations, that is, delivery by psychology students without specialist mental health training and digital delivery, was explored. Methods: Participants (N=8) monitored the number of intrusive memories from an index trauma (occurring 3‐16 years previously) in a daily diary at baseline, during the intervention, and postintervention at 1-month and 3-month follow-ups. The intervention was delivered digitally with guidance from clinical psychologists or psychology students. A repeated AB design was used (“A”: preintervention baseline, “B”: intervention phase). Intrusions were targeted one by one, creating repetitions of an AB design (ie, length of baseline “A” and intervention “B” varied for each memory). Results: The number of intrusive memories reduced for all participants from the baseline phase compared with the intervention phase, although the reduction was minimal for 2 participants (6.3%‐93%). The number of intrusive memories continued to reduce for 6 out of 8 participants (58%‐100% reduction at 1-month follow-up; 72%‐100% reduction at 3-month follow-up). Symptoms of posttraumatic stress, depression, and anxiety were reduced for most participants postintervention and continued to decrease during the follow-up periods. Functioning was improved for 7 of the 8 participants from baseline to postintervention and continued to improve at the follow-up assessments for 3 participants. The intervention delivered digitally and partly by students was perceived to be an acceptable way to reduce the frequency of intrusive memories by all participants (mean rating 9.5 out of 10). Conclusions: Data from this case series of traumatized women provide preliminary evidence for the effectiveness of this novel brief intervention in reducing intrusive memories of trauma occurring several years ago and in improving functioning and reducing core symptom burden. This study will inform a randomized controlled trial of this novel intervention, which may have considerable implications for large-scale clinical management of traumatized populations.

Background: Cognitive dysfunction (“brain fog”) is a commonly reported post-COVID-19 symptom. Leveraging data from five general population cohorts across four European countries (Estonia, Iceland, Norway, and Sweden), we assessed long-term prevalence of impaired subjective cognitive function among individuals diagnosed with COVID-19 by acute illness severity. Methods: The included cohorts consisted of adult participants recruited from March 2020 and followed with self-report measures of cognitive function and past COVID-19 infection (except one cohort consisting of clinically confirmed COVID-19 cases) through February 2023. In a cross-sectional analysis we contrasted the prevalence of impaired cognitive function among individuals with and without a COVID-19 diagnosis, overall and by illness severity up to 32 months post-diagnosis. We adjusted for age, gender, education, relationship status, binge drinking, body mass index, previous psychiatric diagnosis, number of chronic medical conditions, and response period. In a longitudinal analysis, we assessed potential changes in cognitive function scores before and after COVID-19 diagnosis. Results: The study population consisted of 153,841 participants (71% women), with 31,359 (20.4%) reporting a positive COVID-19 test. Overall, a COVID-19 diagnosis was not statistically significantly associated with increased prevalence ratio (PR) of impaired cognitive function (PR 1.30 [95% CI: 0.98–1.71]). Individuals bedridden due to COVID-19 for 1–6 days (PR 1.38 [95% CI 0.96–1.99]) or ≥ 7 days (2.59 [1.55–4.33]) had higher prevalence of impaired cognitive function compared to those never diagnosed, while individuals never bedridden had a lower prevalence to those never diagnosed with COVID-19 (0.89 [0.80–1.00]). These findings were corroborated in the longitudinal analysis where a pre- to post diagnosis decline in cognitive function was observed among individuals bedridden due to COVID-19 ( p < 0.0001). Conclusions: The data indicates that a severe COVID-19 acute illness course is associated with impaired cognitive function up to 18–32 months after COVID-19 diagnosis.