We evaluated the incremental effect of opioids on chronic back pain patients (CBP) by comparing 50 CBP on opioid therapy (CBP+O; opioid duration >= 3months) to pain intensity-, pain duration-, age-, and sex- matched CBP who were not on opioids (CBP-O). Participants completed the NIH Toolbox's cognitive, affective, sensory, and motor components. Several emotional domains were negatively impacted by opioid usage, and we did not observe any dose- or duration-response relationships within the opioid group. Finally, several domains were similarly disrupted in CBP+O and CBP-O compared to normative data, highlighting the need for CBP-O control groups when studying CBP+O.

The authors have declared no competing interest.

This work is funded by the National Institute of Drug Abuse at National Institutes of Health (1P50DA044121) and the National Institute Of Neurological Disorders And Stroke of the National Institutes of Health under Award Number F31NS126012. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. In addition, this material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1324585.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

Northwestern University Institutional Review Board gave ethical approval for this work.

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.

Yes