for this article. Author's note. This research was supported by a National Institute of Mental Health (NIMH) Research Scientist Award (MH00331), NIMH Research Grant MH46586, and funding from Johnson and Johnson. I thank the parents, infants, and children who participated in these studies and the colleagues who collaborated on the research. Correspondence concerning this article should be addressed to Tiffany M. Field, Touch Research Institute, University of Miami School of Medicine, P.O. Box 016820, Miami, FL 33101. 1270 December 1998 • American Psychologist Copyright 1998 by the American Psychological Association, Inc. 0003-066X/98/$2.00 Vol. 53, No. 12, 1270 1281 Tiffany M. Field that their parents could also benefit from providing the massage at no monetary expense to themselves. The studies are grouped thematically by the primary objective of treatment, for example, facilitating growth or reducing pain. They are organized in a sequence that may seem arbitrary but one that seems to capture the longitudinal progression from primary agendas early in life to those later in life as, for example, focusing on facilitating growth in premature infants for the early life agenda to enhancing immune function, a more primary agenda for later in life. An attempt was made throughout to address potential underlying mechanisms that are unique to the different conditions as well as to discuss an overarching potential mechanism for massage therapy across conditions. Thus, the order selected is facilitating growth; reducing pain; increasing alertness; diminishing stress, anxiety, and depression; and enhancing immune function. Enhancing Growth Animal Models Data from research on rat and monkey models support the use of touch as therapy. In a recent model developed by Saul Schanberg and colleagues, rat pups were first removed from their mother to investigate touch deprivation (Schanberg, 1994). Then, the mother's behavior was simulated to restore the physiology and biochemistry of the rat pups to normal. In several studies, a decrease was noted in growth hormone (ornithine decarboxylase) when the pups were removed from their mother. This decrease was observed in all body organs including heart, liver, and brain and in all parts of the brain including the cerebrum, cerebellum, and brain stem. These values returned to normal when the pups were stimulated using techniques approximating the mother's behavior. A graduate student observed rat mothers' noctumal behavior and noted that they frequently tongue lick, pinch, and carry around the rat pups. When the researchers tried each of these maneuvers, only the tongue licking (simulated by a paintbrush dipped in water and briskly stroked all over the body of the rat pup) restored the growth hormone values to their normal level. Because thermo-regulation might also be a factor, the same study was conducted with an anesthetized mother rat (Schanberg, 1994). The pups could still suckle and maintain their body temperature by continuous contact with the mother rat but were not being tongue licked. The pups experienced similar decreases in growth hormone. More recently, Schanberg and his colleagues discovered a near immediate gene underlying protein synthesis that responds to tactile stimulation, suggesting genetic origins of this touch-growth relationship (Schanberg, 1994). Related studies by Meaney et al. (1990) suggest a long-term impact of handling on the modulation of cortisol (stress hormone) production. Rats who were handled more as pups showed less corticosteroid production, more elaborate dendritic arborization in the hippocampal region, and better maze performance (memory function) in the aging rat. It is, of course, also possible that increased cortisol or increased stress could accelerate development, as in some animal models, and it is also possible that the enhanced hippocampal development may be mediated by some third element, for example, another neurotransmitter or neurohormone. For example, increased serotonin might account for both effects. Parallels in the decreased cortisol-increased hippocampal development relationship have already been noted in human infants at the Hammersmith Hospital in London. Research by Modi and Glover (1995) provided similar documentation of lower cortisol levels in massaged preterm infants, and they currently are examining magnetic resonance imaging (MRI) data for examples of faster development of the hippocampal region in those infants. In a sample of very premature (29 weeks median gestational age) and very low birthweight (Mdn = 980 g), neonates' cortisol concentrations decreased consistently after massage. Modi and Glover are using a computerized subtraction method to document hippocampal development across MRIs taken before and after the massage treatment period. The rat model developed by Meaney et al. for decreased cortisol leading to hippocampal development may have good parallels in the Modi and Glover preterminfant model just as the Schanberg (1994) rat model for stimulation-induced growth has been a good model for massage-induced weight gain in the preterm infant. Greater weight gain has been reported in several studies on preterm infants, including those who are cocaine-exposed and HIV-exposed. In the