Intellectual Development Disorder  

Sometimes called intellectual disability, this type of developmental disorder originates prior to the age of 18 and is characterized by limitations in both intellectual functioning and adaptive behaviors.

Limitations to intellectual functioning are often identified through the use of IQ tests, with an IQ score under 70 often indicating the presence of a limitation. Adaptive behaviors are those that involve practical, everyday skills such as self-care, social interaction, and living skills.

Global Developmental Delay 

This diagnosis is for developmental disabilities in children who are under the age of five. Such delays relate to cognition, social functioning, speech, language, and motor skills.

It is generally seen as a temporary diagnosis applying to kids who are still too young to take standardized IQ tests. Once children reach the age where they are able to take a standardized intelligence test, they may be diagnosed with an intellectual development disorder.

Communication Disorders

These disorders are those that impact the ability to use, understand, or detect language and speech. The DSM-5 identifies four different subtypes of communication disorders: language disorder, speech sound disorder, childhood-onset fluency disorder (stuttering), and social (pragmatic) communication disorder.

Autism Spectrum Disorder 

Autism is characterized by persistent deficits in social interaction and communication in multiple life areas as well as restricted and repetitive patterns of behaviors.

The DSM specifies that symptoms of autism spectrum disorder must be present during the early developmental period and that these symptoms must cause significant impairment in important areas of life including social and occupational functioning.

Attention-Deficit Hyperactivity Disorder (ADHD)

ADHD is characterized by a persistent pattern of hyperactivity and impulsivity and/or inattention that interferes with functioning and presents itself in two or more settings such as at home, work, school, and social situations.⁵

The DSM-5 specifies that several of the symptoms must have been present prior to the age of 12 and that these symptoms must have a negative impact on social, occupational, or academic functioning.