The Effect of Personality Traits on Cognitive Behavioral Therapy Outcomes in Student Pharmacists with Rat Phobia: A Randomized Clinical Trial.

Background: Little is known about which personality traits determine the effectiveness of various types of cognitive-behavioral therapy (CBT) on animal phobia. The objective of the present study was to investigate a possible association between personality traits and the outcome of single- and multi-session CBT.

Methods: The present randomized clinical trial was conducted from November 2018 to May 2019 in Shiraz, Iran. Forty female students with rat phobia, who met the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) criteria, were systematically allocated into a single- and a multi-session therapy group (odd numbers one-session treatment, even numbers multi-session treatment). In both groups, the students were gradually exposed to rats as part of the treatment. Psychological measures (state-anxiety, rat phobia, and disgust questionnaires) were used to compare pre- and post-intervention outcomes. Multivariate analysis of covariance was used to assess which personality traits influenced the intervention outcome. The statistical analysis was performed using SPSS (version 20.0) and P values<0.05 were considered statistically significant.

Results: Rat phobia was positively and significantly affected by conscientiousness (P=0.001) and agreeableness (P=0.003). Of these personality traits, only a higher degree of conscientiousness resulted in a further reduction of state anxiety after the intervention (P=0.005). There were no significant differences between the pre- and post-intervention outcomes.

Conclusion: The outcome of single- and multi-session rat phobia therapies was associated with specific personality traits of the participants, namely conscientiousness and agreeableness. Both intervention methods had an equal effect on reducing rat phobia.