Problems with obesity in the normal population are reviewed, and antipsychotic-induced weight gain is discussed. The data about quetiapine-induced weight changes are analyzed in more detail. Available data from controlled and uncontrolled studies indicate that quetiapine could have a „normalizing“ effect on weight. This is supported also by the positive influence of clozapine and quetiapine combination on the weight and severity of diabetes in patients with clozapine-induced overweight. Considering these results and the fact, that clozapine has a similar pharmacological profile to olanzapine, a trial with a combination of olanzapine and quetiapine in patients with olanzapine-induced overweight was performed.

        Key words: overweight, atypical antipsychotic combination of antipsychotics, quetiapine.