learning disorder. An uneven profile of abilities is common , such as above-average abili-
ties in drawing, design, and other visuospatial  abilities, but slow, effortful, and inaccurate
reading and poor reading comprehension and written expression. Individuals with spe-
cific learning disorder typica lly (but not invariably) exhibit poor performance on psycho-
logical tests of cognitive processing. However,  it remains unclear whether these cognitive
abnormalities are the caus e, correlate, or consequence of th e learning difficulties. Also, al-
though cognitive deficits associated with diff iculties learning to read words are well doc-
umented, those associated with other manifestations of specific learning disorder (e.g.,
reading comprehension, arithmetic computat ion, written expression) are underspecified
or unknown. Moreover, individu als with similar behavioral sy mptoms or test scores are
found to have a variety of cognitive deficits, and many of these processing deficits are also
found in other neurodevelopmental disorders (e.g., attention-deficit/hyperactivity disor-
der [ADHD], autistic spectrum  disorder, communication diso rders, developmental coor-
dination disorder). Thus, asses sment of cognitive processing deficits is not required for
diagnostic assessment. Specific le arning disorder is associated  with increased risk for sui-
cidal ideation and suicide attempts in  children, adolescents, and adults.
There are no known biological markers of spec ific learning disorder. As a group, indi-
viduals with the disorder show circumscribe d alterations in cognitive processing and
brain structure and func tion. Genetic differences are also evident at the group level. But
cognitive testing, neuroimaging, or genetic test ing are not useful for diagnosis at this time.
Prevalence
The prevalence of specific learning disorder across the academic domains of reading, writ-