Erratum to Conference Abstract: “Validation and Comparison of a Digital Digit Symbol Substitution (DSST) Task Performed on Smart Phones With a Traditional Paper-Pencil Version,” by Allen et al. (Biol Psychiatry 2021; (9S):S132–S133); The authors identified an error in the last sentence of the Background, where “CANTAB-DST” should instead have been “Cognition Kit DSST.” In full, the corrected sentence reads: “In collaboration with Adams Clinical, participants with major depressive disorder (MDD) underwent both digital and paper-pencil versions of the DSST offering a unique opportunity to inform usability, as well as compare and validate the smart phone delivered DSST; Cognition Kit DSST.” The abstract has been corrected.