The branch of psychology concerned with the treatment of abnormal mentation and behavior WordNet 3.0 & Open English WordNet

Clinical psychology is an integration of human science, behavioral science, theory, and clinical knowledge for the purpose of understanding, preventing, and relieving psychologically-based distress or dysfunction and to promote subjective well-being and personal development. Wikipedia

A field of psychology that focuses on diagnosis and treatment of psychological disorders. OmegaWiki

A branch of psychology with the purpose of understanding, preventing, and relieving psychologically based distress or dysfunction and to promote subjective well-being and personal development. Wiktionary

Branch of psychology. Wiktionary (translation)