It is not uncommon for intellectual disabilities (ID) and developmental disabilities (DD) to be used interchangeably. However, although there are similarities between the two, experts understand there are also significant differences. It is essential to understand the distinction so individuals can receive the most appropriate services and support.
Intellectual disability is a disability characterized by significant limitations in intellectual functioning and adaptive behavior, which covers a range of everyday social and practical skills. This disability originates before the age of 18.
There are five main types of intellectual disabilities:
This type of intellectual disability is caused by damage to the brain before, during, or shortly after birth. Examples include fetal alcohol syndrome, genetic disorders such as Down syndrome, and acquired brain injuries sustained during infancy or childhood.
Non-organic intellectual disability is not caused by damage to the brain. Instead, it results from social factors such as poverty or poor educational opportunities. It can also be caused by medical conditions such as malnutrition.
Mild intellectual disability is characterized by significant intellectual functioning and adaptive behavior limitations. Individuals with mild ID have an IQ score of 50-70. They are often able to live independently and hold down a job.
Moderate intellectual disability is characterized by significant intellectual functioning and adaptive behavior limitations. Individuals with mild ID have an IQ score of 35-50. They may need help with daily living activities and employment.
Severe intellectual disability is characterized by significant intellectual functioning and adaptive behavior limitations. Individuals with powerful ID have an IQ score of 20-35. They typically require substantial support for daily living activities and employment.
Developmental disabilities are a group of neurological or other impairments that develop before adulthood (usually before age 18), last a person’s lifetime, and result in substantial limitations in three or more major life activities. Many people with developmental disabilities also have co-occurring mental health conditions or other challenges.
The most common developmental disabilities include cerebral palsy, autism spectrum disorder, Down syndrome, Fragile X syndrome, and Fetal Alcohol Spectrum Disorder (FASD).
Cerebral palsy is a neurological disorder that affects muscle coordination and body movement. It is caused by damage to the brain, typically before or during childbirth.
Autism spectrum disorder (ASD) is a neurological disorder that affects social interaction, communication, and behavior. ASD can range from mild to severe.
Down syndrome is a genetic disorder caused by the presence of an extra chromosome 21. It is the most common form of intellectual disability.
Fragile X syndrome is a genetic disorder that causes intellectual disability, behavioral problems, and physical abnormalities. It is the most common inherited form of intellectual disability.
Fetal alcohol spectrum disorder (FASD) is a group of conditions that can occur in individuals whose mothers drank alcohol during pregnancy. FASD is the leading cause of preventable intellectual disability in the United States.
It is important to note that not all intellectual disabilities are developmental disabilities, and vice versa. Developmental disabilities must have onset before adulthood, while intellectual disabilities can develop at any age. In addition, developmental disabilities always involve limitations in three or more major life activities, while intellectual disabilities may or may not. Finally, intellectual disabilities can be caused by damage to the brain (organic), while developmental disabilities cannot.
There is no single cause of intellectual disability. Instead, it is a result of a variety of factors. These include genetic abnormalities, prenatal exposure to toxins such as alcohol or lead, or complications during delivery.
Intellectual disability can vary significantly in terms of severity and symptoms. Some individuals with mild ID may only have difficulty with specific academic skills, while others with severe ID may need help with basic activities of daily living.
There is no single cause of developmental disabilities. Instead, they result from a combination of genetic and environmental factors. Developmental disabilities can range from mild to severe, and symptoms can vary significantly from one individual to the next.
The goal of treatment for intellectual disability is to maximize the individual’s functional abilities and quality of life. Treatment typically includes special education, behavioral therapy, and medication.
Special education is designed to meet the unique needs of individuals with ID. It can be delivered in various settings, such as public schools, private schools, or home-based instruction.
Behavioral therapy is a type of psychotherapy that aims to help individuals with ID develop skills and coping mechanisms to deal with everyday challenges.
Medication can be used to treat co-occurring mental health conditions, such as anxiety or depression. Medication can also manage specific symptoms, such as hyperactivity or impulsivity.
Intellectual disability is a neurological disorder that affects cognitive functioning and skills. Developmental disabilities are a group of conditions that can occur in individuals whose development is impaired. Intellectual disabilities can be mild, moderate, or severe, and symptoms can vary significantly from one individual to the next. Treatment for intellectual disability typically includes special education, behavioral therapy, and medication.