Patients admitted to the study will be treated with risperidone at doses of physicians' discretion beginning with 2 mg daily on days 1 and 2. On days 3 and 4 the risperidone dose could be increased to a maximum of 4 mg daily or decreased to 1mg daily. On days 5 to study end the dose could be increased to a maximum of 6 mg daily or decreased to a minimum of 1mg (see ref #18). Dose of risperidone will be a secondary outcome measure (see reference #15 & #16). No washout from previous medication is required but patients who received depot neuroleptics within the past 2 weeks or more than 300 mg of chlorpromazine equivalents in the past three days will be excluded. Trihexyphenidyl (up to 4 mg daily) will be available as necessary for extrapyramidal symptoms and benzodiazepines for sleep. Valnoctamide or placebo will be begun at doses of 600 mg per day (200 mg three times daily) and increased to 1200 mg (400 mg three times daily) after four days. This dose is based on relative anticonvulsant effects of valproate and valnoctamide in animal studies (1, 6, 10).