1. Thirty patients with peptic ulcer were interviewed concerning psychoneurotic, psychosomatic, and behavioral symptoms before and after hospital treatment.2. Many of the patients (21 of 30) showed changes, some profound and some very subtle, ranging from acute hysterical reactions to chronic neurotic invalidism. Unfocussed anxiety occurred in some and some acquired other psychosomatic diseases.3. The specific changes seem to depend somehow more on the individual's basic conflict and the way in which he has worked the symptom into his pattern of defense rather than on the specific type of medical or surgical treatment, though the dramatic neurotic breakdowns seem to occur mainly after surgery.4. Cases followed over long periods show that the basic neurotic conflict of the individual determines what will happen in regard to specific symptoms. The outcome of medical or surgical treatment can be predicted only if this basic dynamic unit is known.Abstract Teaser