Trajectories of sleep problems from adolescence to adulthood. Linking two population-based studies from Norway Mari Hysing, Allison G. Harvey, Tormod Bøe, Ove Heradstveit, Øystein Vedaa, Børge Sivertsen November 2020 PDF Cite DOI "Adolescence" "Insomnia" "Sleep duration" "Sleep problems" "Young adults"