What does the cryptic crossword clue "People badly affected by anxiety changed 5 down (9)" mean?

The definition is "People badly affected by anxiety". The wordplay uses an anagram. anagram of COUNTRIES = NEUROTICS The answer is NEUROTICS.

People badly affected by anxiety changed 5 down (9)

Guardian Cryptic #29104 | 10 Across | 2023-06-23 flower