This is an observational, multicenter, open and prospective study. The primary objective is to evaluate safety of risperidone in patients who are overweight and/or obese. It is expected to enroll 1500 patients with Schizophrenia or Schizoaffective disorder, in which physicians considered the use of risperidone as treatment under clinical practice with a BMI (Body Mass Index) >25, or for patients that have increased their body weight >7% in the last year with the previous treatment (even with a BMI< 25), and for patients that have shown intolerance to a previous antipsychotic treatment. The study drug is risperidone, 3-6 mg per day, orally, during the study period (6 months). All data collected will be prospective and will include the following: demographic data, psychiatric history and comorbidities, concomitant treatment, body weight, treatment history , other illness related to obesity ( such as diabetes mellitus I & II, hypertension and hypercholesterolemia) and adverse events. Observational Study: Risperidone, 3-6 mg per day, orally, during the study period (6 months).