Thirty-six healthy patients with schizophrenia or psychotic disorders, each of whom will be drug-free at study initiation, will be admitted to the hospital and will each receive two doses of ACP-104, and one dose of placebo, orally every 3-5 days over a two-week period. The patients will be divided into six groups of up to six and minimum of 3 patients each. Group 1 will consist of six patients who will receive single 25mg and 50mg doses of ACP-104 and placebo in random, but rising dose, order over a two-week period. Data from group one will be collected to determine ACP-104's safety, tolerability, and pharmacokinetics. Group 2 will be enrolled in the study once study data from Group 1 has demonstrated the safety of ACP-104. Group 2 will receive a 25mg pre-conditioning dose of ACP-104. Following the pre-conditioning dose, 75mg and 100mg single doses of ACP-104 will be administered in random, but rising dose, order, over a two-week period. Group 3 will be enrolled in the study once study data from Group 2 has demonstrated the safety of ACP-104. Group 3 will receive a 25mg pre-conditioning dose of ACP-104. Following the pre-conditioning dose, 125mg and 150mg single doses of ACP-104 will be administered in random, but rising dose, order, over a two-week period. Group 4 will be enrolled in the study once study data from Group 3 has demonstrated the safety of ACP-104. Group 4 will receive a 25mg pre-conditioning dose of ACP-104. Following the pre-conditioning dose, 175mg and 200mg single doses of ACP-104 will be administered in random, but rising dose, order, over a two-week period. Group 5 will be enrolled in the study once study data from Group 4 has demonstrated the safety of ACP-104. Group 5 will receive a 25mg pre-conditioning dose of ACP-104. Following the pre-conditioning dose, 225mg and 250mg single doses of ACP-104 will be administered in random, but rising dose, order, over a two week period. Group 6 will be enrolled in the study once study data from Group 5 has demonstrated the safety of ACP-104. Group 6 will receive a 25mg pre-conditioning dose of ACP-104. Following the pre-conditioning dose, 275mg and 300mg single doses of ACP-104 will be administered in random, but rising dose, order, over a two-week period. Groups 1-6 will be monitored closely and safety procedures and evaluations will be performed on all medication days. Safety assessments will include: physical examinations, vital signs (3-positional blood pressure and pulse rate, respiration rate, and oral body temperature), clinical laboratory tests, ECGs (Electrocardiogram), coordination tests, questions about symptoms and side effects. Once all medication days have been completed, the condition of the patient will be assessed, and, at that time, it will be determined whether the patient's condition is suitable for release from the hospital or whether further monitoring of the patient's condition as an inpatient is needed.
