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Date of Award


Degree Type

Dissertation (On-Campus Access Only)

Degree Name

Doctor of Psychology (PsyD)

Committee Chair

Linda Krug Porzelius, PhD

Second Advisor

Jay Thomas, PhD, ABPP


This study cancer patients examined relationships among illusions, mental health and treatment choices in order to determine whether cancer patients benefit from an illusory belief style. Participants were 87 Stage One and Stage Two cancer patients recruited from local medical centers and the internet. An illusory belief style consists of three main components: an unrealistically positive self-view, distorted beliefs of personal control, and overly optimistic future beliefs. Pearson correlations and independent-samples t-tests were utilized. Findings indicated that illusions were negatively associated with levels of depression and anxiety, and positively related to efforts to seek and understand medical information about cancer and treatment. Levels of depression and anxiety were negatively correlated with efforts to seek and understand medical information. No support was found for relationships between illusory beliefs and participation in alternative treatments. Results suggested that illusory beliefs are adaptive to mental health. Illusory beliefs were related to an increased ability to participate in cancer treatment decisions. Depression and anxiety were related to participation in cancer treatment decisions. Findings indicate that health care professionals need to routinely screen for and treat psychological distress in cancer patients, to improve quality of life and promote optimal participation in cancer treatment. An illusory belief style may benefit early-stage cancer patients.