Hello thanks for asking from HCM for your health related queries I can understand your concern. Sizodon is Risperidon and the drug is an antipsychotic drug. The drug causes sedation, increased appetite, drowsiness and weight gain as side effects. The symptoms like weakness, drowsiness, feelings like energy has been drained etc are occurring most probably due to the side effects of the drug though the doses he is taking are not very high. In my opinion if the symptoms are intolerable then I d advise you to take him to his psychiatrist and discuss about some other antipsychotic drug. Drugs like Aripiprazole, Paliperidone etc are relatively better tolerated and have efficacy almost similar to Sizodon. You can discuss with his psychiatrist for these drugs. Thanks, Hope this helps you. Take care Dr. Seikhoo Bishnoi, Psychiatrist