Final answer:
Intellectual Disability is diagnosed with an IQ below 70 and includes challenges in personal independence and social skills. Individuals face difficulties in adaptive functioning that were present before 18. There are four levels of severity, all of which affect conceptual, social, and practical functioning.
Step-by-step explanation:
Intellectual Development Disorder, now referred to as Intellectual Disability (ID), is typically identified with an IQ score below 70. Individuals with such a diagnosis may face challenges related to personal independence and social skills. An intellectual disability involves difficulties in adaptive functioning such as conceptual, social, and practical skills that were present before the age of 18.
For example, individuals with ID might struggle with learning basic academic skills, understanding abstract concepts, or adapting to new situations. They may also have obstacles in social interactions, interpreting social cues, and developing friendships. These challenges may cause difficulties in personal care and daily life tasks that require a degree of independence.
Intellectual Disability has four subtypes: mild, moderate, severe, and profound. The key criteria for diagnosis include a lower IQ score, major deficits in adaptive functioning, and manifestation of these before the age of 18, in accordance with criteria from the Diagnostic and Statistical Manual of Psychological Disorders (DSM-5).