The essence of early intervention is that it can correct developmental delays and deficits triggered by premature birth, birth injuries, and dysfunctions occurring in the early weeks or months of life, as soon as possible. A thorough and accurate diagnosis of the infant, covering multiple areas of development, must precede the initiation of therapy. Teamwork is vital to the diagnostic process which is based on monitoring the infant. 

Combined perspective of the psychological and speech therapy background of selective mutism. Terminology, etiology and symptomatology. Comparing classification systems.