Do negative or positive emotions differentially impact mortality after adult stem cell transplant?

Multiple diverse biomedical variables have been shown to affect outcome after hematopoietic stem cell transplantation (HSCT). Whether psychosocial variables should be added to the list is controversial. Some empirical reports have fueled skepticism about the relationship between behavioral variables and HSCT survival. Most of these reports have methodological shortcomings. Their samples were small in size and included heterogeneous patient populations with different malignant disease and disease stages. Most data analyses did not control adequately for biomedical factors using multivariate analyses. The pre-transplant evaluations differed from study to study, making cross-study generalizations difficult. Nevertheless, a few recently published studies challenge this skepticism, and provide evidence for deleterious effects of depressive symptomatology on HSCT outcome. This mini review integrates the new data with previously reviewed data, focusing on the differential impact of negative and positive emotional profiles on survival. Pre-transplant negative emotional profiles are associated with worse survival in the long term, whereas pre-transplant optimism about transplant appears to affect survival in the short term. These data have practical implications for transplant teams. Pre-transplant psychological evaluation should assess for specific adverse behavioral risk factors, particularly higher levels of depression and lower levels of optimistic expectations about transplant. Transplant centers should develop collaborative studies to further test the effects of these adverse behavioral risk factors, and run multicenter hypothesis-driven clinical trials of psychological intervention protocols. Such studies should aim to better define pragmatics of assessment and intervention (timing, assessment tools, personnel), and evaluate their contribution to improving outcome after transplant.