Presentation of developmental delay and disability
Developmental delays are suspected if a child fails to achieve key developmental milestones by the usual age, after allowing for normal variation1. The delay may affect one (specific) or more (global) developmental domains, and can vary from mild to severe or profound. Once it becomes apparent that a child is unlikely to ‘catch up’ to their peers (eg by 5 years of age), it is preferable to use the term ‘disability’ rather than ‘delay’ in discussions with parents.
Manifestations of developmental delay or disability warrant referral for specialist developmental assessment (eg by a paediatrician) after initial health assessment by the general practitioner (GP); see Initial assessment in general practice.
In children, parental concerns about behaviour or learning are often an early indicator of developmental disability. Alerting features in an adolescent or adult include a history of delayed milestones, attending special school, illiteracy or behavioural problems. Consider also how much support the person requires in order to participate in daily life and their community.
Comorbidity is common in people with developmental disability; for example, up to 38% of young people with intellectual disability experience mental health problems.
|
Age |
Skills attained |
|---|---|
|
6 months |
alert and responsive, smile and laugh appropriately responsive vocalisation using a variety of vowel sounds visually fix on an object and follow it through 180 degrees pick up objects with a palmar grasp and pass from hand to hand sit momentarily with a straight back and hold the head steady |
|
12 months |
indicate their wants through sound and simple gesture (eg pointing) say at least 2 words with meaning and imitate a range of speech sounds pick up small objects with a thumb–finger grasp and put in and out of a container sit independently, crawl and pull themselves up starting to enjoy cause and effect of play |
|
2 years |
growing sense of independence which may manifest as oppositional behaviours eat with a spoon, remove some clothes, and start to develop make-believe play and imitate their parents’ activities speech includes two-word phrases scribble and build a tower of 4 blocks walk well, run and manage steps enjoy playing alongside other children |
|
3.5 years |
increasingly independent in their personal care—brush their own teeth with little help, put on some items of clothing sociable and can name a friend speak in short sentences and point to pictures and name them imitate drawing a vertical line on paper and build a tower of 8 blocks kick and throw a ball interact with other children during play, mimic adult activities and mannerisms, play imaginary and creative games |
|
5 years |
dress and undress independently with little assistance speak clearly in sentences, understand some prepositions and name colours copy a circle and cross, draw a primitive person good motor skills—can run, climb, hop, pedal a tricycle play well-developed imaginary games, play simple board and card games, has good conversational skills in play |
|
Area of development affected |
Manifestation |
Possible neurodevelopmental diagnoses |
|---|---|---|
|
global |
delays in more than one area of development |
intellectual disability, global developmental delay |
|
motor |
persistent primitive reflexes, motor delay, late walking |
cerebral palsy, neuromuscular disorder |
|
speech and language |
speech delay, limited understanding, unusual or inappropriate use of language |
specific language disorder, hearing impairment, autism, intellectual disability |
|
social and behavioural |
excessive irritability, reduced or increased activity, aggression, sleep disturbance, odd or obsessive behaviour, narrow or unusual play patterns, interpersonal difficulties, social isolation |
autism, attention deficit hyperactivity disorder, intellectual disability |
|
cognitive |
difficulty with planning shopping, managing banking and catching public transport |
intellectual disability |
|
sensory |
not responding to sounds, objects or pictures |
hearing or vision impairment |