Developmental Delays

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The formal definition of developmentally delayed encompasses all of the cognitive and physical conditions that impair a child’s ability to master developmental milestones on the timeline given for neurotypical children. Medical and mental health practitioners define the term according to the following criteria and guidelines:

Evaluation and Diagnostic Criteria

When a child is accessed to determine if a developmental delay is present, the evaluator will often ask the parents questions about the child’s development and will also gather their own data through interacting and playing with the child. Common types of developmental delays include:

--motor delays, which may affect an infant with poor muscle tone or a young toddler who is not yet crawling or pulling up to stand by 12 months of age. Parents may also be concerned about this type of delay if their child is not yet walking once he or she reaches 18 months of age.

--speech and language delays, which may be present in a toddler who is not yet able to speak single words or form 2-3 word sentences after reaching 3 years of age. Though the typical range for speech development is quite broad (some children begin to use words between 12-18 months of age while others reach this milestone after age 2), parents may want to request an evaluation for non-verbal children over 3.

--communication delays, which may be suspected in a toddler who has not transitioned into the “tantruming” stage or a preschooler who shows no interest in playing and conversing with other children.

Once a diagnosis is made, children with delays can receive support and therapeutic help from a number of sources, such as pediatric neurologists, developmental psychologists, early intervention programs, and public school special education systems.


The prognosis for children with developmental delays depends on both the severity of a particular condition and the age at which a child receives a diagnosis. Children with mild to moderate delays who receive treatment early in life are likely to develop on par with their peers by their school years. Those who are diagnosed later in childhood may take longer to catch up with other children, though support services and therapies are still highly beneficial at this stage. Most children with delays grow to enjoy an independent and functional adult life.

Severe developmental delays often involve greater challenges throughout childhood and adulthood, and people with these conditions may need part or full-time professional support and personal assistance in their daily lives.

Though some parents may initially be unclear on the definition of developmentally delayed, they can easily seek guidance and clarification from medical personnel and psychiatric professionals. The types of developmental disabilities differ, but assistance is available to children regardless of their specific delays.


(1) Encyclopedia of Children’s Health–

(2) University of Michigan Health System–

(3) My Child Without Limits–