Barry Eye

Date Approved


Degree Type

Open Access Dissertation

Degree Name

Doctor of Philosophy (PhD)



Committee Member

Ellen Koch

Committee Member

Tamara Loverich

Committee Member

Thomas Waltz

Committee Member

Katherine Porter


More than one billion humans currently suffer from one or more mental health difficulties, the leading cause of disability in the world. Psychotherapy is well-established as efficacious and cost effective in the treatment of mental health difficulties, particularly the widely-used family of cognitive behavioral therapies (CBT). The most prominent, new CBT–acceptance and commitment therapy (ACT)–has shown efficacy equal to or better than traditional CBT across a range of such difficulties. ACT’s novel approach to language, defusion (the opposite of fusion), can help improve mental health by changing one’s relationship with their thoughts. Efforts to better understand this mechanism of ACT has been hampered by the absence of a robust fusion measure until recently, with the creation of the Cognitive Fusion Questionnaire (CFQ). The present study sought to confirm the psychometrics of the CFQ with a large adult undergraduate student sample from the U.S. and to further expand our empirical understanding of the relationship between fusion and other important clinical constructs. Results showed that the CFQ exhibited strong internal consistency reliability; a unidimensional factor structure; and construct, concurrent criterion, and incremental validity in relation to a number of other important clinical scales as predicted. However, the results also showed that the factor structure of the CFQ was shared with the predominant measure of the central ACT construct of psychological flexibility, implying the two are measuring the same underlying construct. These results, limitations of the present study and the CFQ, and future research directions are discussed.

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Psychology Commons