Introduction: novel therapies in developmental disabilities--hope, reason, and evidence.

Complementary and alternative medicine (CAM) is used both alongside (complementary) and as a substitute for (alternative) conventional therapies. Although CAM use is reported to be high among children with typical development, reported rates for CAM use to address symptoms of children with developmental disabilities may be higher. Increased use in this population may relate to hope for amelioration of symptoms, concerns regarding side effects of conventional treatments, and a need on the part of families to participate in decision making regarding their child's care. Primary health care providers may find that the child's needs are best served when they maintain a dialogue with families to evaluate the evidence supporting novel therapies. Interventions need to be assessed in an evidence based fashion whether or not they are initially preceived as CAM. This issue of Mental Retardation and Developmental Disabilities Research Reviews contains reviews of CAM used to treat several developmental disabilities as well as some broader discussions related to the determinants of CAM use, current efforts to evaluate novel therapies, and how to consider the possibility of placebo effects. Copyright 2005 Wiley-Liss, Inc.