Primary Care Coding Alert

Question: The physician diagnosed a teen patient with mixed anxiety and depressive disorder, but I’m confused about how to code that. Can I code them together?

Florida subscriber

Answer: This is tricky and will likely require you to query the physician to see whether they’ve determined a specific link between the two conditions. Per the AHA ICD-10-CM Coding Clinic (2021, Volume 8, Number 1), you should assign F32.9 (Major depressive disorder, single episode, unspecified) and F41.9 (Anxiety disorder, unspecified) “when the documentation has not established a linkage between the depression and the anxiety.” You might alternatively assign F41.8 (Other specified anxiety disorders), which is a code that “includes anxiety depression (mild or not persistent) and mixed anxiety and depressive disorder” and identifies “a distinct clinical diagnosis” known as “mixed anxiety and depressive disorder, also known as MADD.”

Another code choice, F34.1 (Dysthymic disorder), may also come into play, as one of the synonyms for this condition is “persistent anxiety depression.” Here, though, the key term is “persistent,” as the condition is not episodic, like depression, but continuously experienced for a period of at least a year in childhood or adolescence (see, for example, www.nami.org/Blogs/NAMI-Blog/ January-2018/Understanding-Dysthymia). Note that F41.8 is in an Excludes2 note under F34.1, so if the physician diagnoses the patient with dysthymic disorder and some “other specified anxiety disorder,” you will report both diagnoses rather than F34.1 alone.