Effects of perceived treatment on quality of life and medical outcomes in a double-blind placebo surgery trial.

CONTEXT: This study was part of a large double-blind sham surgery-controlled trial designed to determine the effectiveness of transplantation of human embryonic dopamine neurons into the brains of persons with advanced Parkinson's disease. This portion of the study investigated the quality of life (QOL) of participants during the 1 year of double-blind follow-up. OBJECTIVES: To determine whether QOL improved more in the transplant group than in the sham surgery group and to investigate outcomes at 1 year based on perceived treatment (the type of surgery patients thought they received). DESIGN: Participants were randomly assigned to receive either the transplant or sham surgery. Reported results are from the 1-year double-blind period. SETTING: Participants were recruited from across the United States and Canada. Assessment and surgery were conducted at 2 separate university medical centers. PARTICIPANTS: A volunteer sample of 40 persons with idiopathic Parkinson's disease participated in the transplant ("parent") study, and 30 agreed to participate in the related QOL study: 12 received the transplant and 18 received sham surgery. INTERVENTIONS: Interventions in the parent study were transplantation and sham brain surgery. Assessments of QOL were made at baseline and 4, 8, and 12 months after surgery. MAIN OUTCOME MEASURES: Comparison of the actual transplant and sham surgery groups and the perceived treatment groups on QOL and medical outcomes. We also investigated change over time. RESULTS: There were 2 differences or changes over time in the transplant and sham surgery groups. Based on perceived treatment, or treatment patients thought they received, there were numerous differences and changes over time. In all cases, those who thought they received the transplant reported better scores. Blind ratings by medical staff showed similar results. CONCLUSIONS: The placebo effect was very strong in this study, demonstrating the value of placebo-controlled surgical trials.

Does personality change as a result of fetal tissue transplantation in the brain?

This study examined the effects on personality of transplantation of fetal tissue into the brains of participants in a double-blind placebo control trial for the treatment of Parkinson's disease (PD). Thirty persons with PD (equal numbers of males and females) participated in a larger study investigating the efficacy of transplantation of fetal neural tissue versus placebo surgery. Participants were randomly assigned to receive either the fetal transplant or placebo surgery. The blind was lifted for all patients approximately 13 months after surgery, at which time individuals who had received the placebo surgery could choose to receive the transplant surgery. In this study 12 persons originally received the transplant and 18 received placebo surgery. The NEO Five-Factor Inventory (NEO-FFI), a commonly used measure of personality characteristics, was administered to participants at baseline, 12, and 24 months after surgery. Scores at baseline for the Openness and Agreeableness scales were significantly higher for this sample of PD patients than scores for the normative group. There were no changes on any of the five scales from baseline to 12 months for the total group. The only significant change in the original transplant group was a decrease in Conscientiousness from baseline to 24 months. There were no changes over time among the group who had placebo surgery first and then the transplant. Results indicate that personality, as measured by the NEO-FFI, basically remained stable during the two-year follow-up period of this study. In this case, no change is regarded as a positive outcome.