WASHINGTON -- Government inspectors told lawmakers Wednesday that Medicare officials need to do more to stop doctors from prescribing powerful psychiatric drugs to nursing home patients with dementia, an unapproved practice that has flourished despite repeated government warnings.So-called antipsychotic drugs are designed to help control hallucinations, delusions and other abnormal behavior in people suffering from schizophrenia and bipolar disorder, but they're also given to hundreds of thousands of elderly nursing home patients in the U.S.