Correction to Mattes

When the letter “Ketamine After Two Antidepressants?” by Jeffrey A. Mattes, M.D. (doi: 10.1176/appi.ajp.2021.21060576) was published in the December 2021 issue, three words (“and augmenting agents”) were missing from a portion of the first sentence, which should have read “there is considerable data (2) indicating that other antidepressants (either alone or combined), and augmenting agents such as lithium, thyroxine, etc., can help patients who have not responded to prior antidepressants.” The letter was reposted online on January 28, 2022, with the words added.