Pursuant to the DSM-5, or most current edition, a diagnosis of Intellectual Developmental Disorder requires consideration of both clinical assessment and standardized testing of intellectual and adaptive functions. Individual cognitive profiles based on neuropsychological testing as well as cross-battery intellectual assessment using multiple IQ or cognitive tests to create a profile will also be considered when making a determination of eligibility. Specifically, an individual must meet the following three (3) criteria in order to receive a diagnosis:
To meet this criterion, individuals must have a valid IQ score of approximately 70 or below, including a margin of measurement error of +/- 5, establishing a range of eligibility from 65-75. Instruments must be normed for the individual's sociocultural background and native language. When multiple tests have been conducted for an individual, a clinical assessment of the validity of the results and other related factors (i.e., statistically significant splits between scores) of each singular test will occur as to provide the appropriate clinical judgment of an individual's score.
To meet this criterion, individuals must have one domain in adaptive functioning-conceptual, social, or practical-sufficiently impaired as to necessitate ongoing support in order to have the individual perform adequately at school, at work, at home, or in the community. For the purposes of this Criterion B, the conceptual (academic) domain involves competence in memory, language, reading, writing, math reasoning, acquisition of practical knowledge, problem solving, and judgment in novel situations, among others. The social domain involves awareness of others' thoughts, feelings, and experiences; empathy; interpersonal communication skills; friendship abilities; and social judgment, among others. The practical domain involves learning and self-management across life settings, including personal care, job responsibilities; money management, recreation, self-management of behavior, and school and work task organization, among others.
Adaptive functioning is evaluated by using both clinical evaluation and individualized, culturally appropriate, psychometrically sound measures. Standardized measures are used with knowledgeable informants (e.g., parent or other family members; teacher; counselor; care provider) and the individual to the extent possible. Additional sources of information include educational, developmental, medical and mental health evaluations. In situations where standardized testing is difficult or impossible (e.g., sensory impairment, severe problem behavior), the individual may be diagnosed with unspecified intellectual development disorder. Intellectual capacity, education, motivation, socialization, personality features, vocational opportunity, cultural experience, and coexisting other medical conditions or mental disorders influence adaptive functioning.
To meet this criterion, a comprehensive evaluation is required. A comprehensive evaluation includes an assessment of intellectual capacity and adaptive functioning; identification of genetic and non-genetic etiologies; evaluation for associated medical conditions (e.g., cerebral palsy, seizure disorder); and evaluation for cooccurring mental, emotional, and behavioral disorders. Components of the evaluation may include basic pre-and perinatal medical history, three-generational family pedigree, physical examination, genetic evaluation, and metabolic screening and neuroimaging assessment.
S.C. Code Regs. 88-515