Cognitive function in congenital adrenal hyperplasia.

Cognition in patients with CAH has not been as well studied as other aspects of psychologic function. Nevertheless, it is possible to make some conclusions and to offer a number of hypotheses for further study (Table 1). First, patients with CAH do not seem to have an overall intellectual advantage as a direct consequence of the disease. The high IQs reported in some groups of patients with CAH are also reported in their siblings and probably reflect sampling bias. Second, it is possible that, on average, patients with salt-wasting CAH have lower overall ability than patients with the simple-virilizing form, but both groups are well within the normal range, and there is considerable variability among both groups. Third, the evidence to date does not confirm that patients with CAH are more likely to have diagnosable learning disabilities when compared with their unaffected relatives, but this issue has not been well studied with the appropriate psychoeducational assessments. It is unlikely that patients with CAH are at substantially increased risk for frank learning disabilities, but they may be likely to have problems in specific areas. Fourth, females with CAH seem to have enhanced spatial ability as a result of exposure to high levels of androgens early in development. The neural substrate of this advantage is unknown but a subject of active research. It is unclear whether when compared with their unaffected siblings, females with CAH are better in other abilities that are typically performed best by males or worse in abilities typically performed best by females. Fifth, it is likely that patients with CAH have other cognitive changes as a consequence of disease characteristics (besides androgens) and of the treatment of the disease. Some evidence suggests that patients with CAH are more likely to have white-matter brain changes produced by the disease and its treatment. This has not been well studied but should be because of the potential clinical implications. It is reasonable to hypothesize that there will be cognitive changes that reflect effects of undertreatment (e.g., ACTH effects on attention) and other changes that reflect effects of overtreatment (e.g., glucocorticoid effects on memory). Some of these effects may be transient, reflecting acute brain changes, whereas others may become chronic as a result of permanent brain changes with repeated exposure. There is need for continuing study of cognition in patients with CAH. Such studies will provide basic information about hormonal effects on cognition and the neural mechanisms that mediate those effects. They will also provide important clinical information to guide psychologic and medical treatment of patients.