Kratom (Mitragyna speciosa Korth.) use has increased substantially over the past decade outside of its indigenous regions, especially for the self-treatment of psychiatric conditions. An anonymous, cross-sectional, online survey was completed by 4,945 people who use kratom (PWUK) between July 2019 and July 2020. A total of 2,296 respondents completed an extended survey that included clinical scales for measuring attention deficit hyperactivity disorder (ADHD), posttraumatic stress disorder (PTSD), depressive and anxiety disorders. PWUK and met criteria for ADHD, PTSD, depressive or anxiety disorders were primarily middle-aged (31-50 years), employed, college-level educated, and reported greater concurrent or prior use of kratom with cannabis, cannabidiol, and benzodiazepines. For all psychiatric conditions, PWUK reported decreased depressive and anxious moods than before kratom use. Based on this self-report study, observational and other clinical studies are warranted for kratom. (PsycInfo Database Record (c) 2023 APA, all rights reserved).