This report is a comparative study of the relative effeots of sodium amobarbital and thorazine on performance during a brief series of psychomotor and psychological efficiency tests. The experimental subjects constituted a sub-sample of patients drawn from a larger group undergoing study to ascertain the effects of massive doses of thorazine. 1 The dosage of sodium amobarbital was 38i gr., administered intravenously. This was selected because it is a clinical dosage frequently used in practice to allay tension and the symptoms of emotional disturbance. The dosage of thorazine was a massive one, 800 rag. daily by mouth.