IntroductionSince 2007, kratom use in the United States has increased, centered around nonmedical self-treatment of pain, psychiatric, and substance use disorder symptoms. Reports of kratom withdrawal have emerged amidst description of therapeutic effects, yet we know little about disordered use. Our objective was to assess Diagnostic and Statistical Manual-5 substance use disorder for kratom (“kratom use disorder,” KUD) and examine kratom withdrawal symptoms among those who ever used regularly. We also sought to identify clinical characteristics of respondents who qualified for current, remitted, or never KUD.MethodsBetween April and May 2021, we re-recruited online respondents who reported lifetime kratom use on an unrelated survey into our cross-sectional kratom survey study, permitting a diverse sample of current and former kratom-using persons.ResultsA total of 129/289 (44.6%) evaluable surveys were obtained. Over half (52.7%) of respondents never met KUD diagnostic criteria; 17.8% were assessed remitted, and 29.5% met current (past-year) KUD threshold. For past-year KUD, severity was: 14.0% mild, 7.0% moderate, and 8.5% severe. Pain, psychiatric symptoms, and polydrug use were found across all groups. KUD symptoms reflected increased use, tolerance, withdrawal, unsuccessful quit attempts, and craving; 9.3% reported decreases in important social, occupational, or recreational activities because of use. Withdrawal symptoms were moderate and included gastrointestinal upset, restlessness, anxiety, irritability, fatigue/low energy, and craving.ConclusionsAs assessed here, tolerance and withdrawal are primary KUD features rather than psychosocial impairments. As kratomis often used among persons with a myriad of health conditions, clinicians should be aware of and assess for kratom use and withdrawal.