Here's a summary of a post from Lars Svensson at Vox EU:
The Riksbank is wrong about the debt: Higher policy rates increase rather than decrease the household-debt ratio, by Lars E.O. Svensson, Vox EU: The Riksbank maintains high policy rates since it fears that a lower rate would increase the household-debt ratio. This column argues that a higher rate in fact leads to a higher debt ratio, not a lower one. The higher rate reduces nominal housing prices and new mortgages, but since the new mortgages are such a small share of total mortgages, the total nominal debt falls very slowly. Yet nominal GDP falls much faster, so the debt-to-GDP ratio rises.