Tremendous growth in opioid prescribing over two decades in the USA has correlated with proportional increases in diversion, addiction, and overdose deaths. Pseudoaddiction, a concept coined in 1989, has frequently been cited to indicate that under-treatment of pain, rather than addiction, is the more pressing and authentic clinical problem in opioid-seeking patients. This investigative review searched Medline articles containing the term “pseudoaddiction” to determine its footprint in the literature with a focus on how it has been characterized and empirically validated. By 2014, pseudoaddiction was discussed in 224 articles. Only 18 of these articles contributed to or questioned pseudoaddiction from an anecdotal or theoretical standpoint, and none empirically tested or confirmed its existence. Twelve of these articles, including all four that acknowledged pharmaceutical funding, were proponents of pseudoaddiction. These papers described pseudoaddiction as an iatrogenic disease resulting from withholding opioids for pain that can be diagnosed, prevented, and treated with more aggressive opioid treatment. In contrast, six articles, none with pharmaceutical support, questioned pseudoaddiction as a clinical construct. Empirical evidence supporting pseudoaddiction as a diagnosis distinct from addiction has not emerged. Nevertheless, the term has been accepted and proliferated in the literature as a justification for opioid therapy for non-terminal pain in patients who may appear to be addicted but should not, from the perspective of pseudoaddiction, be diagnosed with addiction. Future studies should examine whether acceptance of pseudoaddiction has complicated accurate pain assessment and treatment, and whether it has contributed to or reflected medical-cultural shifts that produced the iatrogenic opioid addiction epidemic.