Incidence rates of treated mental disorders before and during the COVID-19 pandemic - a nationwide study comparing trends in the period 2015 to 2021 (preprint)

Background: There is a concern that exposure to psychosocial stressors during the COVID-19 pandemic may have led to a higher incidence of mental disorders. Thus, this study aimed to compare trends in incidence rates of depressive disorder, anxiety disorders, obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), and eating disorders in primary- and specialist health care before (2015-2019) and during the COVID-19 pandemic (2020-2021). Methods: We used aggregated population registry data to calculate incidence rates of mental disorders from primary (The Norwegian Control and Payment of Health Reimbursement Registry (KUHR)) and specialist (The Norwegian Patient Registry (NPR)) health care. The analyses included all Norwegian residents aged 18-65 during the study period. Incident cases were defined as having no previous registration with the same mental disorder in KUHR (from 2006) or NPR (from 2008). We used linear prediction models and mean models to compare incidence rates and test trends before and during the pandemic. Results: During the pandemic, the incidence rates among women were higher or as predicted for OCD in specialist care and for eating disorders in both primary and specialist care. Incidence rates for depression and phobia/OCD among both genders in primary care and phobic anxiety disorders among both genders in specialist care were lower or as predicted. Conclusion: The COVID-19 pandemic may have led to more women needing treatment for OCD and eating disorders in the Norwegian population. The decreased incidence rates for some disorders might indicate that some individuals either avoided seeking help or had improved mental health during the pandemic.

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 (preprint)

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. Objective: 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 Reimbursement register. 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.

Prevalence of Mental Disorders, Suicidal Ideation and Suicides in the General Population Before and During the COVID-19 Pandemic in Norway. A Population-Based Repeated Cross-Sectional Analysis from the HUNT Study and the Norwegian Cause of Death Registry (preprint)

Background: Self-report data indicate a deterioration of population mental health in many countries during the COVID-19 pandemic. A Norwegian epidemiological diagnostic psychiatric interview survey was conducted from January to September 2020, allowing for comparison of current prevalence of mental disorders from before through different pandemic phases. Prevalence of suicide deaths were compared between 2020 and 2014-2018.Methods: Participants from the Trøndelag Health Study (HUNT) in Trondheim were recruited through repeated probability sampling. Using the Composite International Diagnostic Interview (CIDI 5.0) (n=2,154), current prevalence of mental disorders was examined in repeated cross-sectional analyses. Data on suicide was retrieved from the Norwegian Cause of Death Registry and compared for the first phase of the pandemic with the same months 2014-2018. Findings: Prevalence of mental disorders decreased significantly from the pre-pandemic phase (January 28th to March 11th 2020; 15·3% [95% CI 12·4-18·8]) to the first pandemic phase (March 12th – May 31st ; 8·7% [6·8-11·0]) and was fairly stable through the interim phase (June 1st July 31st ; 14·2% [11·4-17·5]) and the second phase (August 1st -September 18th ; 11·9% [9·0-15·6]). Suicidal ideation was non-significantly (n.s) increased during the pandemic. Suicide deaths were 15% lower (n.s) in March-May 2020 (n=140) compared with the same months pooled over 2014-2018 (n=165). Interpretation: We found no increase in mental disorders or suicides during the COVID-19 pandemic up through early autumn 2020. COVID-19 related mortality, transmission rates, intensity and implementation of measures and lockdowns have been less severe in Norway than many other countries and could account for these results.Funding: NoneDeclaration of Interests: Dr. Hotopf reports grants from European Commission IMI/EFPIA, grants from National Institute of Health Research, grants from Medical Research Council, and grants from Economic and Social Research Council outside the submitted work. In the past 3 years, Dr. Kessler was a consultant for Datastat, Inc., Sage Pharmaceuticals, and Takeda. The authors Dr. Knudsen, Dr. Gustavson, Dr. Krokstad, Dr. Skogen, Dr. Stene-Larsen, Dr. Øverland and Dr. Reneflot report no conflict of interest.Ethics Approval Statement: The survey was a collaboration between the Norwegian Institute of Public Health (NIPH) and the HUNT Research Centre and approved by the Regional Committee for Medical Research Ethics (2017/28/REK midt).