Children diagnosed with sickle cell disease (SCD) struggle with executive functions (EF); however, there is a paucity of research on neuropsychological outcomes in adults with SCD. This study aimed to examine differences in EF between adults with SCD and healthy controls. Thirty- one patients with SCD and 34 healthy controls (ages 18-45) participating in an IRB-approved Children’s Hospital Los Angeles (CHLA) study of cerebral blood flow underwent neuropsychological evaluation using the Delis–Kaplan Executive Function System (D-KEFS) Trail Making and Color Word Interference Tests and the Wechsler Adult Intelligence Scale - Fourth Edition (WAIS-IV) Digit Span subtest to assess various aspects of EF. The Wechsler Abbreviated Scale of Intelligence - Second Edition (WASI-II) was administered to estimate general intellectual ability. There were no significant differences between groups related to age, gender, race, parental education, or general intellectual ability; however, the control group was estimated to have significantly higher current combined annual family income as compared to patients with SCD, x2 (6, N = 65) = 10.87, p = .02. Therefore, income was statistically controlled for during analyses. Both groups performed in the solidly average range across EF measures and no significant differences were noted between groups in working memory, F(1) = .009, p = .93, ηp2 = .000; inhibition, F(1) = .156, p = .03, ηp2 = .03; or cognitive flexibility, F(1) = 3.11, p = .08, ηp2 = .06. Adults with SCD in this study performed comparably to healthy controls. Early treatment with hydroxyurea to the maximum tolerated dose may improve prognosis and serve as a protective factor against EF deficits in adults with SCD. However, additional research is needed to better understand how treatment protocols influence neuropsychological outcomes in this population.

Library of Congress Subject Headings

Sickle cell anemia -- Psychology; Executive functions (Neuropsychology) -- Testing; Neuropsychology -- Research

Date of Award


School Affiliation

Graduate School of Education and Psychology



Degree Type


Degree Name


Faculty Advisor

Shelly Harrell