Research impact is assessed partly by how the research has made demonstrable contributions to academia and society at large. Most funding agencies rely on journal metrics to judge research impact and guide funding decisions, yet these metrics can be a poor measure of individual article impact. While citation numbers of individual articles have emerged as a surrogate measure, these can take time to accrue. Consequently, article-level research impact is not known until well after publication. Web-based alternative metrics—commonly known as altmetrics—collect data on the frequency of online mentions of a publication from web-based services and can be applied to gauge almost immediate research impact. Various social media platforms provide the bulk of altmetric data, with Twitter yielding the richest data set. As research has yet to evaluate the role of Twitter in assessing research impact in psychiatry, we investigated this association in a 2-year sample of publications from the American Journal of Psychiatry.