Social workers are committed to the protection and empowerment of weak populations, of those people who are least powerful. Gradually, social work started to rely more on problem-solving methods, client-focused therapy, family theories, and, more recently, cognitive behavior theories, constructivist theories, and positive psychology developments. Clinical social work today operates in a variety of settings in the statutory, voluntary, and private sectors. Clinical social workers have always been interested in helping clients change effectively. The importance of empirical study, valid information, and intervention effectiveness has always been accentuated by the social work field’s central objectives of increasing accountability, maintaining exemplary ethics and norms, and establishing clear definitions and goals. Cognitive behavior theory emphasizes several components. First and foremost, human learning involves cognitive mediational processes. Social workers need to look for effective methods for change, and CBT methods are very promising in this respect.