APA Style Blog: Headings

Title Case

Title case is used to capitalize the following types of titles and headings in APA Style:

Titles of references (e.g., book titles, article titles) when they appear in the text of a paper,

Titles of inventories or tests,

Headings at Levels 1 and 2,

The title of your own paper and of named sections within it (e.g., the Discussion section), and

Titles of periodicals—journals, magazines, or newspapers—which are also italicized (e.g., Journal of Counseling Psychology, The New York Times).

via APA Style Blog: Headings.