The policies and guidelines which have shaped the attitude and practice relating to the use of opioids for the treatment of chronic pain have undergone remarkable changes. Recent decades have witnessed a surge, followed by a decline, and near prohibition, in the use of opioids. Cognitive biases appeared to be play an important role in how the scientific data upon which policy and guidelines are based is presented, and interpreted. These biases may have had a greater influence on policymakers than the data itself. This paper reviews data from four key areas identified as relating to the use of opioids, and the creation of guidelines including (a) the surge and decline in opioid prescribing, (b) sham distinctions, (c) reliance on the numerical pain rating (NPR) and (d) the consequences associated with the use/discontinuation of opioids. Published studies, commentaries, and guidelines were selected based on their ability to illustrate a particular bias and/or to highlight discrepancies in the scientific literature. Discrepancies and inconsistences in the presentation and interpretation of data in these areas were identified. Focused illusion, linguistic uncertainty, and heuristic failure were found to be prevalent cognitive biases. Cognitive biases appear to be influential in the making of policy and guidelines related to the sue of opioids. Overlooking these biases may result in decisions that negatively impact clinical practice and patient safety.