Depression is one of the most common psychological disorders, to which psychologists have paid special attention. In recent years, many methods have been employed for treating depression. According to research findings, the family has an important role in the development, maintenance and treatment of the depression syndrome. Research findings also reveal that Cognitive-Behavior Therapy (CBT) is effective in the treatment of depression. Therefore, family therapy, with an emphasis on the cognitive behavioral approach, is suggested as an effective approach in treating depression. Based on these grounds, the main purpose of this study was to examine the effects of family therapy as an effective treatment for depression. This research was a case study and data were obtained through clinical interviews and psychological tests. In this study, a severely depressed 17 years-old participant was successfully treated by using a combination of cognitive-behavioral techniques, emphasizing on family therapy. Results show the effectiveness of these methods in treating depression. Finally, consistency and inconsistency of the findings with the result of other studies in discussed.