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Does Functioning Differ Before and After Daylight Savings Time Changes Among Patients with Bipolar Disorder?

Douglas, Erika L. (2007) Does Functioning Differ Before and After Daylight Savings Time Changes Among Patients with Bipolar Disorder? Master's Thesis, University of Pittsburgh. (Unpublished)

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Longitudinal studies, which are characterized by repeated measures taken on individual subjects, play a major role in the field of public health. One area of research that has been particularly impacted by longitudinal studies is bipolar disorder. Patients afflicted with this illness often suffer from occupational as well as social disruptions in their normal functioning, not to mention the burden this disease creates on both families of bipolar patients as well as the nation's economy. One factor believed to be involved in the pathogenesis of bipolar disorder is circadian abnormalities, such as disturbances in sleep and appetite patterns. One such source of circadian rhythm disruption is brought about by the semi-annual occurrence of daylight savings time (DST). While research has shown that DST may have detrimental, though temporary, effects on circadian functioning in normal populations, little has been done to investigate the effects of DST in patients with bipolar disorder. Due to the high cost and disturbance in daily functioning that bipolar patients frequently experience, it is of public health importance to further investigate this disorder so that more effective ways to manage it may be discovered. A population-averaged approach was taken using GEE modeling on the Global Assessment of Functioning (GAF) outcome, and multinomial logistic regression modeling on the Clinical Global Impressions (CGI). This thesis reviews the literature on methods for analyzing longitudinal data in bipolar research, including both GEE and multinomial regression modeling; also reviewed are two commonly used mental illness rating scales: the GAF and the CGI. A subset of data from a bipolar disorder treatment and maintenance trial (7,315 repeated observations on 1175 patients) was used to conduct the present investigation. The results indicate that while DST changes are significantly associated with changes in clinical symptom severity, the magnitude of these differences is relatively small.


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Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
Douglas, Erika
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairStone, Roslyn A.roslyn@pitt.eduROSLYN
Committee MemberMazumdar, Satimaz1@pitt.eduMAZ1
Committee MemberNimgaonkar, Vishwajitvishwajitnl@upmc.eduNIMGA
Date: 25 September 2007
Date Type: Completion
Defense Date: 11 June 2007
Approval Date: 25 September 2007
Submission Date: 14 June 2007
Access Restriction: No restriction; Release the ETD for access worldwide immediately.
Institution: University of Pittsburgh
Schools and Programs: School of Public Health > Biostatistics
Degree: MS - Master of Science
Thesis Type: Master's Thesis
Refereed: Yes
Uncontrolled Keywords: bipolar disorder; circadian functioning; Clinical Global Impressions; daylight savings time; GEE; Global Assessment of Functioning; multinomial logistic regression; ordinal logistic regression
Other ID:, etd-06142007-104749
Date Deposited: 10 Nov 2011 19:47
Last Modified: 19 Dec 2016 14:36


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