If you do use an abbreviation in a running head, you can use it straightaway without definition.
Retain these abbreviations because the reader will need them to retrieve the source (you also do not need to define them—just present them as-is).
See more about this in our post on cite what you see.
by Chelsea Lee This post will address how to use abbreviations in APA Style—specifically, how to use acronyms, which are abbreviations made up of the first letters of each word in a phrase. You can find abbreviations discussed in the The first time you use an abbreviation in the text, present both the spelled-out version and the short form.
When the spelled-out version first appears in the narrative of the sentence, put the abbreviation in parentheses after it: If your reference has a group author, the name of the group can sometimes be abbreviated—for example, American Psychological Association can be abbreviated to APA.
You are not obligated to abbreviate the name of a group author, but you can if the abbreviation would help avoid cumbersome repetition and will appear more than three times in the paper.
As with other abbreviations, spell out the name of the group upon first mention in the text and then provide the abbreviation.
If the name of the group first appears in the narrative, put the abbreviation, a comma, and the year for the citation in parentheses after it.
If you have several references by the same group author, you only need to abbreviate the name once (see here for how to handle references with the same author and date).
If the spelled-out version of the term appears in the narrative for the first time, put the abbreviation and the author–date citation in parentheses after it, separated by a semicolon. There is no official guidance on whether to use abbreviations in the running head.We recommend that you avoid them, unless the abbreviation is well-known and there is no alternative running head that would be better.