70 Neurodevelopmental Disorders
Finally, the learning difficulty may be restricted to one academic skill or domain (e.g., read-
ing single words, retrieving or  calculating number facts).
Comprehensive assessment is required. Specifi c learning disorder can only be diagnosed
after formal education starts bu t can be diagnosed at any point afterward in children, adoles-
cents, or adults, providing there is evidence of onset during the years of formal schooling (i.e.,
the developmental period). No sing le data source is sufficient fo r a diagnosis of specific learn-
ing disorder. Rather, specific learning disorder is a clinical diagnosis based on a synthesis of
the individual’s medical, develo pmental, educational, and family  history; the history of the
learning difficulty, including it s previous and current manifestat ion; the impact of the diffi-
culty on academic, occupational, or social functioning; previo us or current school reports;
portfolios of work requiring academic skills; curriculum-based assessments; and previous or
current scores from individual standardized test s of academic achievemen t. If an intellectual,
sensory, neurological, or motor disorder is susp ected, then the clinical assessment for specific
learning disorder should also include methods appropriate for these disorders. Thus, compre-
hensive assessment will involve professionals with expertise in specific learning disorder and
psychological/cognitive assessment. Since specific  learning disorder typically persists into
adulthood, reassessment is rarely necessary, un less indicated by marked changes in the learn-
ing difficulties (amelioration or worsenin g) or requested for specific purposes.
Associated Features Supporting Diagnosis
Specific learning disorder is frequently but not invariably preceded, in preschool years, by
delays in attention, language, or motor skills that may pers ist and co-occur with specific
learning disorder. An uneven profile of abilities is common , such as above-average abili-