Assessment typically includes:
* Intelligence testing: Standardized tests like the Stanford-Binet Intelligence Scales or the Wechsler Intelligence Scales (WISC for children, WAIS for adults) measure cognitive abilities, including verbal comprehension, perceptual reasoning, working memory, and processing speed. A significantly low score on these tests is one component of the diagnosis, but not the only one.
* Adaptive behavior assessment: This assesses how well a person can cope with everyday demands in various life areas, such as communication, self-care, social skills, and independent living. Standardized scales are used to measure adaptive behavior, considering the individual's age and cultural background. Examples include the Adaptive Behavior Assessment System (ABAS) and the Vineland Adaptive Behavior Scales.
* Medical evaluation: This may involve a physical exam, genetic testing, or neuroimaging to rule out underlying medical conditions that could contribute to intellectual disability.
Important Considerations:
* Age: Intellectual disability is diagnosed in childhood, but assessment methods and interpretations vary depending on the child's developmental stage.
* Cultural factors: Test results must be interpreted cautiously, considering the individual's cultural background and language proficiency. A test designed for one culture may not accurately reflect the abilities of someone from a different culture.
* Multiple professionals: Diagnosis usually involves a team of professionals, including psychologists, educators, and sometimes medical doctors.
It's crucial to remember that intellectual disability is a broad spectrum, and individuals with intellectual disability have diverse abilities and needs. The severity is determined by the level of support required to function in daily life. A proper diagnosis is made by qualified professionals through a thorough and multi-faceted evaluation.