A prospective study of the association among impaired executive functioning, childhood attentional problems, and the development of bipolar disorder
Studies of adults who have been diagnosed with, and treated for, bipolar disorder have shown that these patients exhibit impairment on measures of executive functioning. However, it is unclear whether executive dysfunction precedes the diagnosis of bipolar illness, or develops subsequent to its onset. Moreover, investigators have failed to control for the effects of premorbid attentional problems on cognitive performance in these patients. The present authors explored these questions using data from a longitudinal prospective study of individuals at risk for major mood disorder. Results revealed that 67% of participants who met criteria for bipolar disorder in young adulthood showed impairment on the Wisconsin Card Sorting Test (WCST) when they were assessed during adolescence, as compared with 17% of individuals with no major mood diagnosis, and 19% with unipolar depression. This association between performance on the WCST and bipolar illness was not accounted for by high rates of premorbid attentional disturbance. In fact, among participants with early attentional problems, only those who ultimately developed bipolar disorder exhibited impairment on the WCST. Early attentional problems that preceded unipolar depression or no mood disorder were not associated with executive dysfunction. a
c1 Address correspondence and reprint requests to: Stephanie E. Meyer, PhD, UCLA-NPI, 760 Westwood Plaza, Room 48-241, Los Angeles, CA 90024; E-mail: firstname.lastname@example.org.
a The findings presented in this paper come from the doctoral dissertation of the first author, which was funded by an NIMH Intramural Research Training Award. The authors are enormously grateful to Roger E. Meyer for his comments on earlier drafts of this paper and to Anne Mayfield, without whom this project would not have been possible. We are deeply indebted to Ann S. Masten, W. Andrew Collins, L. Alan Sroufe, Monica Luciana, and Carrie Borchardt, who provided invaluable guidance throughout all stages of this project, as well as Robert Asarnow, who was an important mentor during the review process. In addition, we acknowledge the contributions of Gail Inoff–Germain, who administered diagnostic interviews and neuropsychological measures at adolescent follow-up; Rula B. Garside, who undertook the painstaking job of establishing interrater reliability; Erika Sundstrom, who devoted many hours to data organization and quality assurance; and Sara Avery Torvik and Patricia Kasdan, whose combined gifts of organization and warmth created a comfortable atmosphere for study participants. Finally, we thank the extraordinary research participants of the NIMH Childrearing Study, who have shown enormous bravery and dedication by sharing with us 23 years of their lives.