Numerous studies have demonstrated that existential therapy is effective in promoting mental health and improving individuals’ quality of life. Existential therapy encourages individuals to reflect on their lives and existence, drawing on personal strength and willpower to pursue life’s highest goals, while seeking to create meaning in human life. The present study aimed to examine the effectiveness of existential therapy in reducing depression. The research hypotheses were tested using a single-case experimental design with a stepwise multiple baseline approach. The intervention consisted of eight 45-minute sessions conducted with three patients, along with one- and three-month follow-up assessments. Data collection tools included the Beck Depression Inventory and the Rumination Questionnaire. Data were analyzed using recovery percentage, effect size, and graphical analysis methods. The results indicated that existential therapy produced significant changes in participants’ scores and led to noticeable improvements in their conditions. In conclusion, existential therapy appears to be an effective approach for reducing depression and rumination in patients with depressive disorders.
