The study presented here has several important, take-home messages. First, based on the results of this study, withdrawal from opioid and/or benzodiazepine therapy does not result in a measurable change in neurocognitive functioning measured by DS or DSST. Second, a relationship of Pain Intensity to level of functionality has been shown. This is well known, and its finding here reinforces the validity of the methods used herein. Third, there is confirmation that mood greatly effects functioning both physically – as indicated by the BDI/PDI relationship alluded to by the correlational analyses, and psychologically – as borne out by the Δ BDI/ Δ DSST relationship found in both the correlational and hierarchical linear regression analyses. Again, the relationship of mood to functionality, like that of pain intensity to functionality, is well established and its presence in these results reinforces the validity of the methods used. Fourth, changes in mood were found to be the most significant predictor of changes in DSST Scaled score. Fifth, Interdisciplinary treatment of chronic pain provides measurable benefit to all individuals regardless of pre-treatment medication status.