Clinical psychology is a branch of psychology that specializes in the research, assessment, diagnosis, evaluation, prevention, and treatment of emotional and behavioral disorders. By extension, occupational clinical psychology (OCP) may be understood as the emergent specialty in psychology concerned with emotional and behavioral disorders in occupational settings and organizations. "Occupational clinical psychology" is a term first coined by James S.J. Manuso in 1975; Manuso (1983) then elaborated on this term in his edited volume Occupational Clinical Psychology. He gave primary credit for the early development of the fiend to Harry Levinson (1983), who wrote the first chapter in the 1983 book titled Clinical Psychology in Organizational Practice. There is now extensive application of clinical psychology to occupational settings and organizational practice.