Date of Award

Fall 2019

Document Type

Open Access Dissertation


Epidemiology and Biostatistics

First Advisor

Angela Liese


Type 1 diabetes (T1D) is one of the most frequently diagnosed chronic illnesses among youth, and has many long-term complications, including retinopathy, neuropathy, and cardiovascular disease. The risk of these complications may be reduced through maintaining glycemic control and one potential risk factor for failure to achieve optimal glycemic control is elevated depressive symptoms among youth and young adults (YYA) with T1D. YYA with T1D are at increased risk of depression, which has been associated with adverse outcomes such as poor adherence to self-management and poor glycemic control. Although a robust body of research exists on the association between comorbid depression and glycemic control among persons with T1D, little research has been conducted on the change in depressive symptoms over time among YYA with T1D. Of interest in the current investigation is whether there are subgroups of individuals among YYA with T1D who demonstrate distinct trajectories of depressive symptoms over time, whether there are baseline predictors of these trajectory groups, and whether trajectory groups predict two health outcomes: glycemic control and arterial stiffness, a precursor to cardiovascular disease.

Using data from YYA recently diagnosed with T1D who were enrolled in the SEARCH for Diabetes in Youth Study between 2002-2005, we identified five depressive symptom trajectories with group-based trajectory modeling based on Center for Epidemiologic Studies - Depression (CES-D) scores collected at up to four timepoints

over a five-year period. Most of the sample reported little to no or minimal depressive symptoms at any timepoint, whereas a small proportion of the sample reported potentially clinically significant symptoms – either decreasing from mild to minimal, increasing from mild to moderate, or chronic, moderate symptoms. The baseline predictors that differentiated between those who report little to no symptoms and those who report clinically significant symptoms include female sex, experiencing at least one severe hypoglycemic and/or diabetic ketoacidosis episode, living in a single-parent home, using psychiatric medications, and cigarette use. We found that depressive symptom trajectory groups were associated with glycemic control, such that those who report stable minimal and decreasing mild to minimal depressive symptoms were more likely to demonstrate high-risk glycemic control compared to those who reported little to no depressive symptoms. There were no significant differences in arterial stiffness among the depressive symptom trajectory groups.

This dissertation has implications for improving the understanding of the course, predictors, and health outcomes of depressive symptoms among YYA with T1D. We found that most YYA with T1D do not experience clinically significant depressive symptoms during the first five years following diabetes diagnosis; however, around 8% reported either increasing mild to moderate symptoms or chronic moderate symptoms during this timeframe. Therefore, it is important that YYA with T1D are screened for depression during visits with their health provider and that appropriate resources are available to treat depression in this population. Further research is needed to clarify the association between depressive symptom trajectories and health outcomes, as our results

showed that high-risk glycemic control and arterial stiffness were not elevated among those with the greatest burden of depressive symptoms.

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Epidemiology Commons