In a randomized, double blind, placebo controlled trial, 44 patients with moderate to severe obsessive compulsive disorder (OCD) were given either L-carnosine or placebo daily in addition to fluvoxamine. After 10 weeks of treatment there were significant reductions in obsessive compulsive symptoms in the group given L-carnosine compared to placebo.
Arabzadeh S, Shahhossenie M, Mesgarpour B, et al. (2017). L-carnosine as an adjuvant to fluvoxamine in treatment of obsessive compulsive disorder: A randomized double-blind study. Hum Psychopharmacol. 32(4) ces: