Data from the IMF says European households hold a similar level of debt if not more (especially the case in northern Europe):
https://en.wikipedia.org/wiki/List_of_countries_by_household...
The US used to be an outlier in this regard if you look back to 2000, but over the past 25+ years American households have stayed pretty much the same while their European counterparts have grown debt substantially.
It is almost entirely mortgage debt backed by the collateral of housing.