highly significantp < 0.001
The effect of time was highly significant ( F (1.77, 529.13) = 54.54, p < 0.001, η p 2 = 0.15) and is described by a significant rise in strain from pre to peak pandemic ( t (306) = 7.07, p < 0.001, d = 0.40 [0.29; 0.52]), which was followed by an even sharper decline from peak to downturn ( t (306) = − 16.23, p < 0.001, d = − 0.93 [− 1.06; − 0.79]) that resulted in values even below the pre-pandemic baseline ( t (306) = − 7.73, p < 0.001, d = − 0.44 [− 0.56; − 0.32]).