Background: Students with a generalized anxiety disorder (GAD) are so worried about potential events in the future that they cannot easily live at the moment and are unable to experience and enjoy positive and pleasant ongoing events. Objectives: This study aimed to investigate the effects of mode deactivation therapy (MDT) and Hofmann’s cognitive behavioral therapy (CBT) on anxiety and self-concept clarity in students with GAD. Methods: This quasi-experimental research adopted a pretest-posttest design with a control group. The statistical population included all high school students with GAD in Bushehr (Iran) in 2021. The convenience sampling method was employed to select 45 students as the sample, who were then randomly assigned to the MDT, CBT, and control groups (15 participants per group). The participants completed the state-trait anxiety inventory and the Self-concept Clarity Scale in two stages, pretest and posttest. The first experimental group received twelve weekly 120-minute sessions of an MDT program, whereas the second experimental group received twelve weekly 120-minute sessions of a CBT program. The analysis of covariance and the Bonferroni test was used for data analysis in SPSS-26. Results: The mean ± SD of the posttest score of state anxiety in MDT and CBT and control groups was 41.53 ± 3.33, 47.67 ± 5.39, and 58.67 ± 6.23, respectively. Moreover, the mean ± SD of the posttest score of trait anxiety in MDT and CBT and control groups was 43.80 ± 5.60, 48.47 ± 5.57, and 56.47 ± 4.04, respectively. Results indicated significant differences between the posttests of groups (P < 0.001). According to the results, both interventions alleviated anxiety and enhanced self-concept clarity in the experimental groups compared with the control group. Furthermore, MDT outperformed CBT in anxiety alleviation and self-concept clarity improvement. Conclusions: In conclusion, MDT was more effective in treating patients with different needs and complications due to its personalized nature, whereas CBT was less efficient in treating non-anxiety disorders due to focusing mainly on social anxiety disorder.