"Infant mental health" (I-ECMH) refers to how well a child develops socially and emotionally from birth to three.

Infant-early childhood mental health, sometimes referred to as social and emotional health, is the developing capacity of the child from birth to 5 years of age to form close and secure adult and peer relationships; experience, manage, and express a full range of emotions; and explore the environment and learn—all in the context of family, community, and culture. Strategies to improve I-ECMH fall along a promotion, prevention and treatment continuum.

Read the source article at ZERO TO THREE