Antipsychotic drugs are currently used in clinical practice for a variety of mental disorders. Clozapine is the most effective medication for treatment-resistant schizophrenia, in controlling aggression and suicidal behavior in psychosis. Although clozapine is associated with a low likelihood of extrapyramidal symptoms and other neurological side effects, weight gain and metabolic side effects are well known in clinical practice exposing the patient to a greater risk of cardiovascular disorders, premature death, as well as psychosocial issues leading to non-adherence. The mechanisms underlying this pharmacologically activated disorders are still controversial. Based on our in vitro results, we have characterized in vivo the effects of the selective PKCβ inhibitor, Ruboxistaurin (LY-333531) on a preclinical model of long-term clozapine-induced weight gain. Cell biology, biochemistry and psychomotor tests have been performed on wild type and PKCβ (-/-) mutant mice to investigate the contribution of endogenous PKCβ and its pharmacological inhibitor on the neuroleptic effect of clozapine. Lastly, we also shed light on a novel aspect of the mechanism underlying of clozapine-induced weight gain, demonstrating that the clozapine-dependent PKCβ activation promote the inhibition of the lipid droplet-selective autophagy process, opening the way to new therapeutic intervention approach.