Mental disorders often do not fit within a single diagnostic category.

Evidence

Although DSM-5 remains a categorical classification of separate disorders, we recognize that mental disorders do not always fit completely within the boundaries of a single disorder. Some symptom domains, such as depression and anxiety, involve multiple diagnostic categories and may reflect common underlying vulnerabilities for a larger group of disorders. — Gary Goertz, Social Science Concepts and Measurement, 1245

Categorization

• DEFINE: Explains the categorical structure of DSM-5 and its acknowledged limitation that disorders cross category boundaries.
• ADDENDUM: Could support an essay on how classification systems fail when phenomena refuse to stay in one box — parallels the immodesty moral-panic piece’s theme of categories enforcing order on messy reality.