Background: The literature speculates that there may be a relationship between cognitive capacities and levels of fatigue in people with multiple sclerosis (MS), which has been under reported. This study has investigated one aspect of cognition by evaluating the association between Problem-solving ability and the severity of fatigue. Methods: A cross-sectional, descriptive study was used to investigate the association between levels of Problem-solving ability and degrees of fatigue severity. Eighty-five participants living in the city of Shiraz, Iran, completed Cassidy Problem-solving Inventory (PSI) and the Fatigue Severity Scale (FSS). Pearson’ s Product Moment Correlation Coefficient was used to analyze the data. Results: Problem-solving was inversely associated with fatigue (r =-0. 381, P = 0. 009), whereby higher levels of Problem-solving ability were associated with lower degrees of fatigue. Conclusion: The results of this study contributed to the ongoing debate about the linkage between cognition and fatigue in people with MS, suggesting an association between Problem-solving ability and fatigue severity. A possible implication would be the importance of Problem-solving training for people with MS.

Introduction: Generalized Anxiety Disorder (GAD) is one of the most common anxiety disorders, and its treatment is very important. Cognitive-Behavioral Therapy (CBT) based on Dugas' model focuses on the causative agents of this disorder. Therefore, this study aimed to investigate the effectiveness of CBT based on Dugas' model on negative problem orientation and Problem-solving in patients with generalized anxiety disorder. Materials and Methods: In this study in 2020, 30 patients with GAD diagnosis were selected by multi-stage cluster method from psychological clinics in Isfahan, Iran. They were randomly divided into experimental and control groups. The experimental group received 12 sessions of 90-minute CBT based on Dugas' model. Due to the drop in sample, 24 subjects in the pre-test and post-test stages fulfilled Generalized Anxiety Disorder Scale (GAD-7), Negative Problem Orientation Questionnaire (NPOQ), and Heppner Problem Solving Inventory (PSI). Finally, the results were analyzed using the SPSS-21 and multivariate analysis of covariance (MANCOVA). Results: The results of MANCOVA showed that there was generally a significant difference between the experimental and control groups in the variables of negative problem orientation and Problem-solving (P< 0. 01). Conclusion: Cognitive-behavioral therapy based on the Dugas' model, is effective in improving negative problem orientation and Problem-solving in patients with generalized anxiety disorder.