He made his literary debut as poet with Gjennom stillheten en natt (1960).
After graduating from secondary school in 1953, Mehren studied philosophy at the University of Oslo for several years.
[3] He made his literary debut with the poetry collection Gjennom stillheten en natt in 1960.
He has written two plays, Narren og hans hertug (1968, staged at Nationaltheatret), and Den store søndagsfrokosten (1976).
[3] Mehren received the Norwegian Critics Prize for Literature and the Mads Wiel Nygaards Endowment in 1963 for Mot en verden av lys.