Date of Graduation


Document Type


Degree Type



Eberly College of Arts and Sciences



Committee Chair

Amy Fiske

Committee Co-Chair

Barry Edelstein

Committee Member

Barry Edelstein

Committee Member

Nicholas Turiano

Committee Member

Ian Rockett

Committee Member

Chandra Reynolds


Suicide is a significant public health problem among older adults in the United States and around the world. There has been little research to date on longitudinal change in functional disability and depressive symptoms, both of which have been posited to be associated with suicide risk among middle-aged and older adults, and their association with death by suicide. The aims of this study were to 1) characterize longitudinal change in functional disability and depressive symptoms separately; 2) characterize the directional associations between functional disability and depressive symptoms in bivariate models; and 3) determine how different patterns of change among these variables are associated with risk for death by suicide. The study used two larger population-based longitudinal datasets, the Health and Retirement Study (HRS) in the United States, and the Swedish Twin Registry (STR). Results from HRS indicated that change in functional disability and depressive symptoms is characterized by a complex system of effects, including both systematic, linear change effects and proportional change based on the level of each variable at each wave. Functional disability generally increased across time and depressive symptoms remained relatively stable, with some slight increases. A bivariate model where level of disability was associated with subsequent change in depressive symptoms was supported by the data, and latent class membership representing group differences in patterns of change within this model predicted risk for death by suicide. Cognitive impairment was significantly associated with lower risk for death by suicide, and appeared to have a suppressor effect on the association of class membership with death by suicide. In STR, functional disability did not predict risk for death by suicide. Further research is needed to characterize the complex longitudinal associations between disability and depression and their effects on suicide risk, taking into account cognitive status.