Tuomas Laine-Frigren specialises in the history of childhood, migration and mental health. His latest book, Sotalasten monet elämät (2024), examines the experiences of the 70,000 Finnish children evacuated to other Nordic countries during the Second World War. This book is due to be published in Swedish in January 2027. His other areas of interest include the history of psychology, the history of Cold War Hungary, disability studies, and the political history (and weaponisation of) antisemitism. Laine-Frigren is the editor-in-chief of Lähihistoria (Finnish Journal of Contemporary History).