Measuring apathy in a neuropsychological patient sample : factor structure and clinical correlates

Recommended Citation Calamia, Matthew. "Measuring apathy in a neuropsychological patient sample : factor structure and clinical correlates." PhD (Doctor of Philosophy) thesis, ii To my family iii ACKNOWLEDGMENTS First, I would like to thank my advisors, Dan Tranel and Kristian Markon. Dan gave me the freedom to pursue my own research interests throughout my time at Iowa, helped me through the ups and downs of graduate school, and taught me how to shuck corn. Kristian was a constant source of support and guidance and always encouraged me to go a little further on research projects rather that settling for the easiest solution. Both were generous with their knowledge and time. Thanks also to the members of my dissertation committee, past and current: support and encouragement. Apparently sticker charts are motivating for both children and PhD students. Also, thanks to Sara Stasik for providing that same support and encouragement during internship. Finally, I would like to thank my parents and sister for their love and support. After 7 years of weekly video chats and occasional visits, I'm so excited to finally be able to move out of the cornfields and back to the swamp. iv ABSTRACT Apathy, defined as a decrease in purposeful or goal-directed behavior, is common in many neurological disorders. The assessment of apathy in these disorders is important as apathy is associated with differential engagement and response to treatment and future cognitive and functional decline. Although apathy is often described as including three separate symptom dimensions, reflecting diminished interest, action, and emotional expression, investigations of the factor structure of apathy symptoms have been limited by the use of scales which do not comprehensively assess all of three of the proposed dimensions. The current study aimed to develop a novel informant report measure of apathy symptoms, investigate the factor structure of apathy symptoms, and examine the relationship of different types of apathy symptoms to several clinically relevant variables. Participants included 249 informants who reported on an individual with (n=210) or without (n=39) a neurological or psychiatric condition. Results showed the best fitting model of apathy symptoms was a bifactor model in which apathy could be represented as a global dimension with three separate, specific symptom factors reflecting diminished interest and initiative, asociality, and diminished emotional and verbal expression. In general, apathy was associated with poorer cognitive functioning, greater functional impairment, and higher caregiver distress. The specific symptom factors differed …