This essay examines the application of two prominent counseling theories, Behaviorism and Cognitive Behavioral Therapy (CBT), in the treatment of major depressive disorder. It begins by defining depression and its impact, then delves into the core principles of behaviorism, including the contributions of Skinner, Bandura, and Lazarus, and how it uses classical and operant conditioning to modify behaviors. The essay then explores CBT, highlighting the work of Ellis, Beck, and Meichenbaum, focusing on how it addresses dysfunctional thoughts and beliefs. A comparative analysis is provided, contrasting the approaches and discussing their respective strengths and limitations in treating depression, supported by relevant literature and research. The essay concludes by offering a critical evaluation of both theories, considering their applicability and effectiveness in the context of reactive depression and other related factors.