By adulthood, 25%- 30% of individuals with 22q11.2 deletion syndrome (22qDS) develop a psychotic disorder, often schizophrenia, and it is not understood why. Given the known genetic etiology of this disorder and the greatly elevated risk for development of schizophrenia, this group offers the possibility of defining a seemingly homogenous maturational pathway to psychosis. Neurocognitive deficits have been increasingly recognized as an important dimension of schizophrenia, particularly in the executive domain. Thus, we assessed multiple aspects of executive cognition in 22qDS, in order to: 1) characterize performance across this domain as compared to age-matched healthy controls; and 2) determine whether executive function performance is significantly predictive of positive and negative psychotic symptoms in 22qDS above and beyond non-verbal functioning. We assessed psychomotor speed and mental flexibility (Trails-B), working memory (Letter-Number Sequencing: LNS) and D-KEFS verbal fluency. Psychotic symptomatology was measured using scores obtained from the Structured Interview for Prodromal Syndromes (SIPS). 22qDS patients (N= 48, mean age: 15.23) showed impairment relative to healthy controls (N= 37, mean age: 14.97) on all measures of executive functioning. Regression analysis revealed that executive deficits are predictive of positive psychological symptomatology above and beyond non-verbal deficits. Specifically, D-KEFS verbal fluency added meaningfully to the prediction of positive psychiatric symptoms. Given this significant prediction it is suggested that executive function may be an important domain for providing information about the development of psychosis.

LLU Discipline

Clinical Psychology




School of Behavioral Health

First Advisor

Hartman, Richard E.

Second Advisor

Bearden, Carrie E.

Third Advisor

Jenkins, Louis E.

Fourth Advisor

Vermeersch, David

Degree Name

Doctor of Philosophy (PhD)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Psychotic Disorders; Schizophrenia; Regression Analysis

Subject - Local

22qDS; Deletion Syndrome; Genetic Etiology; Structured Interview for Prodromal Syndromes



Page Count


Digital Format


Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Electronic Theses and Dissertations

Collection Website



Loma Linda University. Del E. Webb Memorial Library. University Archives