Professor Ivan Dimitrijevic, a psychiatrist at Belgrade's Medical School, notes that those who torture and kill animals belong to the group of deranged persons with a severe psychotic disorder:
El profesor Ivan Dimitrijevic, psiquiatra de la Escuela Médica de Belgrado, anota que los que torturan y matan animales pertenecen al grupo de personas perturbadas con un severo desorden psicótico: