Dichotomy

Dichotomy refers to the division of one whole idea, thought, or concept into two separate and unrelated ideas. Although the word has different meanings in different disciplines, in psychology it is used in the diagnosis of mental disorders to differentiate a diagnosis based on criteria of client, length of occurrence, severity of occurrence, etc. For instance, a therapist will use DSM-IV criteria to examine the dichotomy between what constitutes moderate depression from severe depression.