People with unmedicated mental illness are less likely to be vaccinated against COVID-19

Vaccination coverage for COVID-19 is high in both people with and without mental illness, according to a large multinational study led by researchers at Karolinska Institutet and published in Nature Communications. However, Swedish registry data revealed that individuals with unmedicated mental illness have lower vaccination levels.

The researchers analysed data from seven studies in five countries (Sweden, Norway, Iceland, Estonia, and Scotland) as part of the COVIDMENT consortium, totalling just over 325,000 individuals, and registry data from Sweden including over 8 million individuals.

The pooled analysis from the COVIDMENT cohort showed that 85 per cent of individuals were vaccinated with the first dose of the COVID-19 vaccine (until September 30, 2021). There was no statistically significant difference in vaccination levels in people with or without a mental illness diagnosis, or with or without anxiety or depressive symptoms.

“The high vaccination coverage among most individuals with mental illness shows that the COVID-19 vaccination campaign has been successful,” says lead author Mary Barker, postdoctoral researcher at the Institute of Environmental Medicine, Karolinska Institutet.

However, Swedish registry data revealed that individuals diagnosed with a mental illness who did not have any dispensed prescription of medication for their mental illness were 9 per cent less likely to receive the first dose of the vaccine. Moreover, individuals with substance use disorder were 16 per cent less likely to be vaccinated.

“More research is needed to explore the reasons behind these associations in order to improve current and future vaccination strategies and ultimately ensure equitable protection against infectious diseases,” says Mary Barker. “As individuals with mental illness are at higher risk of severe COVID-19 outcomes, high vaccination coverage is especially important in this group.”

The research was financed by NordForsk, EU’s Horizon 2020 program, the Swedish Research Council for Health, Working Life and Welfare, the Swedish Research Council, the Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning, the Estonian Research Council, and the Research Council of Norway. Some of the authors have listed potential conflicts of interest, including honoraria from and shareholdings in pharmaceutical companies. See the scientific article for more information.

Publication: “Mental illness and COVID-19 vaccination: a multinational investigation of observational & register-based data”, Mary M. Barker, Kadri Kõiv, Ingibjörg Magnúsdóttir, Hannah Milbourn, Bin Wang, Xinkai Du, Gillian Murphy, Eva Herweijer, Elísabet U. Gísladóttir, Huiqi Li, Anikó Lovik, Anna K. Kähler, Archie Campbell, Maria Feychting, Arna Hauksdóttir, Emily E. Joyce, Edda Bjork Thordardottir, Emma M. Frans, Asle Hoffart, Reedik Mägi, Gunnar Tómasson, Kristjana Ásbjörnsdóttir, Jóhanna Jakobsdóttir, Ole A. Andreassen, Patrick F. Sullivan, Sverre Urnes Johnson, Thor Aspelund, Ragnhild Eek Brandlistuen, Helga Ask, Daniel L. McCartney, Omid V. Ebrahimi, Kelli Lehto, Unnur A. Valdimarsdóttir, Fredrik Nyberg & Fang Fang, Nature Communications, online 26 September 2024, doi: 10.1038/s41467-024-52342-1.