People with intellectual disabilities can present with such a vast variety of impairments,  that you would be surprised to learn they share the same diagnosis. That's because "intellectual disability" is a broad term covering a wide range of symptoms.

So, what is an intellectual disability? Here's a quick overview of the condition, including signs of intellectual disability, how it's diagnosed, and available interventions.

Diagnosis of Intellectual Disability

To be diagnosed with an intellectual disability, a person must meet these three criteria:

1. They have “sub-average intellectual functioning.”
2. They have significant limitations in adaptive behavior in one or more of the following areas: conceptual, social, or practical skills.
3. The condition is apparent before the age of 22.

Let’s explore this in detail.

An IQ test is just one piece of this puzzle, but an important one. (A below-average IQ score may indicate impaired intellectual functioning.) However, someone with impaired intellectual functioning may also struggle with:

• Language processing and problem-solving
• Reading, comprehending, and critical thinking
• Making multi-step plans
• Reasoning and applying logic

Although IQ tests are a useful objective measure of general intelligence, they're not 100% reliable. Some people may struggle to focus during the test or lack the life experience needed to answer certain knowledge-based questions, resulting in below-average scores. Therefore, it's crucial that those administering the test use their clinical judgment when interpreting results.

Someone with impaired adaptive behaviors may struggle with social or practical skills needed to live independently such as:

• Understanding social cues
• Maintaining healthy, normative relationships
• Having difficulty with basic self-care tasks or chores
• Struggling with daily activities, like preparing food or getting ready for bed

Adaptive skills are often assessed by speaking with parents, teachers, and others who interact with the child. Parents, teachers, or healthcare providers will often flag their concerns based on missed milestones or developmental screenings. Adaptive skills may also be evaluated using a standardized test like the Adaptive Behavior Assessment System (ABAS). 

To summarize, a diagnosis of an intellectual disorder requires deficits in general intelligence and life skills, which typically become evident during childhood.

Types of Intellectual Disabilities

Intellectual disability levels vary widely. To better understand each child’s unique needs, the diagnosis is usually categorized into four levels:

• Mild intellectual disability: Individuals with mild intellectual disabilities often face challenges in school and may need additional support. With appropriate guidance, they can usually learn practical life skills and maintain independence. Someone with a mild intellectual disability typically has an IQ between 50 and 70. About 85% of people diagnosed with an intellectual disability fall into this category.
• Moderate intellectual disability: Moderate intellectual disabilities can affect language development, often requiring ongoing support in daily activities and social interactions. With proper intervention, individuals can acquire basic communication and self-care skills. An IQ score between 35 and 50 is typical for this level.
• Severe intellectual disability: Individuals with severe intellectual disabilities face significant challenges in communication, learning, and daily tasks. They often require substantial assistance and benefit from a structured and supportive environment. Someone with a severe intellectual disability typically has an IQ between 20 and 35.
• Profound intellectual disability: This level is rare, affecting only about 1.5% of individuals diagnosed with intellectual disabilities. Most people with profound intellectual disabilities have co-occurring medical conditions or disabilities. Their severe cognitive impairments often result in limited or no communication abilities, and they require constant support for basic needs like mobility and daily living activities. An IQ score below 20 is typical for this level.

Co-occurring Conditions

Individuals with intellectual disabilities often have other co-occurring conditions, most commonly the following:

• Autism Spectrum Disorder (ASD): Some individuals with intellectual disabilities also fall within the autism spectrum.
• Attention-Deficit/Hyperactivity Disorder (ADHD): ADHD commonly coexists with intellectual disabilities.
• Epilepsy: Seizure disorders, like epilepsy, can frequently accompany intellectual disabilities.
• Sensory processing disorders: Heightened or diminished sensitivity to sensory stimulation, such as touch, sound, or light, is common among those with intellectual disabilities.
• Mental health conditions: Conditions like anxiety, depression, or mood disorders can co-occur with intellectual disabilities. These conditions can be challenging to diagnose, especially if the individual has limited verbal capabilities.

Living With an Intellectual Disability

Intellectual disabilities are a lifelong condition. However, with early diagnosis of intellectual disability and appropriate interventions, individuals with the condition can achieve many, if not all, significant milestones and live rich, fulfilling lives. 

Interventions can include:

• Early intervention services: Depending on your state of residence, your child may be eligible to receive early interventions, like speech or occupational therapies.
• Special education: This may include modified lesson plans, individualized instruction, and support services. Your child may also be eligible for an Individualized Education Plan (IEP).
• Behavioral and therapeutic approaches: Behavioral therapies address the adaptive behaviors mentioned above, like social skills and emotional regulation. These interventions often involve working with psychologists, ABA therapists, or other mental health professionals.
• Vocational training: As individuals with intellectual disabilities transition into adulthood, vocational training and support for independent living become essential. This may include skill-building programs, job coaching, and assistance in securing employment.

Parenting in general is no simple task, and parenting a child with intellectual disabilities is even more challenging. It is important to accept the support available to you — be it from government programs, supportive friends, or the broader community. With a strong support system and a lot of patience, you and your child can live a life of growth, connection, and meaningful accomplishments.