NOS2 knockout mice as a model of trichotillomania.

Description of the phenotype observed in mice lacking the nitric oxide synthase 2 (inducible NOS; iNOS; NOS2). The evolution of excessive barbering behavior (hair/whisker trimming) observed in these animals was counteracted by treatment with clomipramine or memantine. Both drugs are effective in the therapy for trichotillomania, a psychiatric condition where patients pull or trim the hair of many body areas.