Theories of Dissociation

Definition of the Concept

The standard dictionary defines dissociation as “the splitting off of certain mental processes from the main body of consciousness, with varying degrees of autonomy resulting.” The word probably owes its origin to the nineteenth-century physician Benjamin Rush, who presented lectures on cases typified by difficulties in speech and rapidity of body movements (Carlson et al. 1981). He later incorporated these lectures (with some changes) on “physiological psychology” into his classical textbook, Medical Inquiries upon the Diseases of the Mind (Rush 1812). He devoted a chapter to what he called “dissociation,” which may be the earliest medical use of the term. Rush applied the term to people who were mentally deranged and who had “an association of unrelated perceptions or ideas, or the inability of the mind to perform the operations of judgment and reason.” In other words, Rush was using the term only to refer to pathological behavior whereas, as I shall show,...