The early years of infancy are the critical developmental building blocks from which all later development occurs. Infant physical and mental or behavioral health are closely tied because an infant's brain is developing the basic wiring (i.e., synaptic connections) for its future based on genetics and early experiences. ^{(31), (32)}   The long period of physical vulnerability and dependence of an infant on a caregiver is nature's way of preparing him/her intellectually, socially, and emotionally. The density of synaptic connections within the brain of infants is related to the appropriateness of the stimulation they receive. Researchers are learning the impact of various environmental stimuli on development and the importance of critical periods of development. Infants learn to trust and love themselves and others through a complex intimate bond between themselves and their caregivers.(33) The sounds they hear become the patterns for their speech and grammar. Breastfeeding optimizes their immune system and stimulates their cognition.(34) The varieties of lights and objects they see organize their visual mechanisms and their visual understanding of the world. Infants who suffer severe social deprivation can “wilt” and die or survive with developmental, mental and behavioral health problems for a lifetime. ^{(35, 36)}

Infants require a dramatic lifestyle change for the adults who care for them and demand almost sheer unselfish devotion. The highest rates of reported abuse and neglect are in infants and preschool children. All families with infants need a social support system, however those who are in stressful life situations — single parents, families of infants with special health care needs, young parents, homeless families, and families where a primary caregiver is ill — need their community's support the most.

Infant mortality is one of the measures most often used to express the quality of a nation's health care system. The United States was 27th (in 1997) among nations in infant mortality. Though the U.S. has a higher infant mortality rate than other industrialized nations, amazing progress has been made. Between 1900 and 1999, U.S. infant mortality dropped from 150 to 7.1 per 1,000 live births. The death rate is higher for infants than for any age group, until age 65. Infant deaths are most likely to occur within the first month of life from birth related events, early birth, and congenital abnormalities. Sudden infant death syndrome (SIDS) is a major risk factor for infants throughout the first year of life. While progress has been made in reducing infant mortality, rates of low birth weight (less than 2,500 grams) increased from 7.4 percent of live births in 1990 to 8.2 percent in 2001. Very low birth weight births (less than 1500 grams) have remained steady or slightly increased through the decade from 1.5 percent of live births in 1990 to 1.6 percent in 2001. Today, more infants survive due to medical progress and advances in technology, but many will also need specialized health and educational interventions throughout their lives. Catastrophic health care costs pose a challenge for private and publicly funded insurance carriers. Florida's public health entity, Children's Medical Services (CMS), was created to support children's with special health care needs. CMS has been given the responsibility for ensuring appropriate family centered early intervention for high-risk infants. Early educational interventions and therapeutic services can make an important difference in the health and well-being of vulnerable high-risk infants.