Prechter Fund research associates, Bethany Pester and Amanda Baker presented posters at the International Neuropsychological Society 42nd Annual Meeting, which took place this February in Seattle.
Clinical and Cognitive Predictors of Work Performance in Bipolar Disorder
Bethany D. Pester, B.A., Amanda M. Baker, B.S., Philip M. Presnell, B.S., Kaley A. Angers, B.S., David F. Marshall, Ph.D., Deborah M. Stringer, Ph.D., Scott A. Langenecker, Ph.D., Masoud Kamali, M.D., Katie Lavin, M.S.W., M.P.H., Melvin G. McInnis, M.D., & Kelly A. Ryan, Ph.D.
Objective: Despite high unemployment and absenteeism in Bipolar Disorder (BD), factors related to work performance are under studied. Our prior work showed that emotion processing and executive functioning predict work status in BD. This study examined whether these same factors predict actual work functioning or if there is a subset of other cognitive/clinical factors that predict work performance.
Participants and Methods: A subsample of employed BD participants from the Prechter Longitudinal Study completed clinical, neuropsychological, and personality evaluations at baseline and a Life Functioning Questionnaire (LFQ) and mood measures at one year. The total work functioning score from the LFQ was used to categorize participants as good (n=26) or poor (n=18) work functioning based on a healthy control comparison group. Subscales assessed included degree of difficulty at work in terms of time spent at work, amount of conflict, satisfaction, and quality of work performance. Groups were compared using eight factor scores previously derived from a factor analysis of neuropsychological tests.
Results: Those with poor functioning had higher one-year depression scores compared to the good functioning group. After controlling for depression, the poor functioning group exhibited significantly worse performance on measures of inhibitory control compared to the good functioning group and had higher neuroticism/extroversion scores. Further, those with worse performance, high conflict with others, and less satisfaction, performed worse on tasks of inhibitory control compared to those with better performance, little conflict, and higher satisfaction. There were no differences between work functioning groups on any of the baseline clinical indices.
Conclusions: Inhibitory control, beyond current depression and history of important clinical indicators, appears to be a strong predictor of work performance, conflict with others, and work satisfaction. Treatments aimed at targeting inhibitory control could lead to better work recovery.
Subjective sleep problems not related to cognitive performance in a large sample of patients with bipolar disorder.
Amanda Baker, BS, Bethany Pester, BA, Philip Presnell, BS, Kaley Angers, BS, Erika Saunders, MD, David Marshall, PhD, Deborah Stringer, PhD, Melvin Mcinnis, MD, Masoud Kamali, MD, Scott Langenecker, PhD, & Kelly Ryan, PhD
Background: Adverse effects of sleep on cognitive functioning have been clearly demonstrated in healthy and ill populations, even when using subjective reports of sleep. However, this relationship in patients with Bipolar Disorder (BD) has not been thoroughly investigated, despite both being pervasive problems, and sleep difficulties contributing to relapse and quality of life. We predict that those who report poorer sleep quality/greater insomnia will perform worse on cognitive tests compared to those who report better sleep.
Method: BD participants (n=260) who were enrolled in the Prechter Longitudinal Study completed a clinical evaluation and a self-report measure of their sleep (Pittsburgh Sleep Quality Index). Current medications were coded based on prior literature. The Hamilton Depression Rating Scale-17 total excluded sleep items. Eight cognitive factors were used to represent memory, executive functioning, emotion processing, and fine motor dexterity.
Results: Controlling for mood, which was significantly related to sleep and all cognitive factors, there was no significant relationship between subjective sleep quality/duration and performance across the cognitive areas (p>.05). As expected, use of sleep inducing medications was significantly related to 7 out of 8 cognitive factors, and to sleep variables; those on sleep inducing medications (n= 187) had worse cognitive performance and sleep quality/duration than those not taking medications. Analyses excluding those on medications continued to show no relationship between sleep and cognitive performance when controlling for mood.
Conclusion: Poor subjective sleep quality was not a predictor of cognitive performance in our BD sample, questioning the reliability of self-report of sleep disturbance in BD. Further studies should investigate the accuracy of self-report measures, use objective sleep measures, or consider other contributors that explain the lack of relationship. Sleep medications are a confounding variable in sleep and cognition research