OUTLINE: This is a multicenter study. Pediatric hematopoietic stem cell transplantation (HSCT) recipients (ages 2 months-18 years) and accompanying parents are asked to complete a baseline assessment battery by the start of transplant conditioning (the 'run-in' period). If either member of the participating dyad fails to complete all study measures* during this time period, the dyad is withdrawn from the study. The dyads are randomized into 1 of 2 intervention arms.