**1. Introduction**

The medical community was called to action by The Centers for Disease Control and Prevention (CDC) 2016 guidelines to decrease exposure to full mu agonist long-term opioid therapy (LTOT) for chronic, non-cancer pain (CNCP) in an effort to stem the resulting sequelae of the increasing incidence of opioid overdose [1]. Less severe, but still disturbing, adverse full mu agonist opioid medication effects are numerous and well documented, ranging from immediate (cognitive impairment, dry mucous membranes, slowed intestinal motility) [2] to long-term and insidious (hypogonadism [3], immune compromise [4], and hyperalgesia) [5,6]. Associations between opioid use and declining mood states have also been well documented, such as a decline in patient-perceived quality of life [7], and increased measures of depression [8–11], catastrophizing [10,12,13], fear avoidance [14], and anxiety [10,12,15,16]. However, unforeseen complications regarding efforts to reduce or discontinue opioid dosing within the patient population that utilizes LTOT are becoming apparent [17,18], with recent reports documenting associated overdose and suicide [19–21]. Improved understanding of psychological features associated with a cohort of patients who successfully ceased LTOT may offer useful directives for how to proceed effectively when LTOT cessation is desired.

One potential alternative to LTOT is buprenorphine. Buprenorphine is an opioid drug with partial mu agonist properties [22]. It can be a safer option than full mu agonist opioids for some patients [23,24], as the dangers of respiratory depression and overdoserelated death associated with opioid use are thought to be conferred by full mu receptor

**Citation:** Silva, M.J.; Coffee, Z.; Yu, C.H.A.; Hu, J. Changes in Psychological Outcomes after Cessation of Full Mu Agonist Long-Term Opioid Therapy for Chronic Pain. *J. Clin. Med.* **2023**, *12*, 1354. https://doi.org/10.3390/ jcm12041354

Academic Editors: Carmen María Galvez Sánchez, Casandra I. Montoro Aguilar, Markus W. Hollmann and Tomoyuki Kawamata

Received: 3 December 2022 Revised: 20 January 2023 Accepted: 2 February 2023 Published: 8 February 2023

**Copyright:** © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

<sup>1</sup> The Focus on Opioid Transitions (FOOT Steps) Program, IPM Medical Group, Walnut Creek, CA 94598, USA

agonism [24,25]. However, partial mu agonism, in the case of buprenorphine, confers potent analgesia [26–29].

The primary aim of this study was to identify changes between psychological assessment questionnaires, pre and post LTOT cessation, for patients with CNCP. We present findings from a retrospective analysis in a cohort of patients with CNCP who were successfully able to cease LTOT through participation in a group, multidisciplinary program [14,30] that offered therapeutic options that included buprenorphine. This study took place prior to reports of declining clinical outcomes after LTOT cessation, which notably did not include the option of buprenorphine in care planning [2–6]. Informed by multiple reports of declining mood with opioid initiation [8–16], the researchers hypothesized that LTOT cessation would result in improved mood outcomes.

#### **2. Materials and Methods**

#### *2.1. Study Design*

De-identified data were collected via a retrospective review of electronic medical records (EMR) from October 2017 to December 2019, comparing the pre- and post-psychological assessment questionnaire scores of 98 patients with CNCP who successfully ceased LTOT use through participation in a previously described, group multidisciplinary program [14,30]. Questionnaires were given to each patient at orientation and at graduation. Pre- and post-LTOT cessation scores were paired and used for analysis in this study.

#### *2.2. Intervention*

The multidisciplinary program [14,30,31] operated as a stand-alone intervention within a larger, multi-center, private practice specializing in CNCP in Northern California. Two centers and clinical teams participated in program administration under one medical director. Patients in the program met for approximately six hours once a week for ten weeks. The standardized curriculum entailed group cognitive behavioral therapy, group home exercise training utilizing complimentary care activities, and individualized medication management. Buprenorphine was offered to each patient as an alternative to LTOT. Extended panel urine drug screening was mandated at each meeting to corroborate participant compliance.
