The International Association for the Study of Pain (IASP) defines pain "as an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage" (IASP Task Force on Taxonomy, 1994). As an emotional experience, pain usually negatively impacts patients' daily lives, not only because of physical impairment but also because of the appearance of neuropsychiatric comorbidities such as depression, anxiety, or even addiction. Because of this complex situation, treating pain and its associated neuropsychiatric pathologies becomes a difficult task for the health-care personnel.Pain and reward are opposed responses processed by interconnected brain areas that keep an adequate cognitive and emotional function (i.e., anterior cingulate cortex, dorsal striatum, and amygdala). Furthermore, pain can modify reward processing by decreasing dopamine (DA) release in nucleus accumbens (NAc), which leads to anhedonia or a negative affect state (Elman, Borsook, & Volkow, 2013;Massaly et al., 2019). Thereby, pain can be an important factor affecting addiction, especially in people with a previous history of drug abuse. In fact, inflammatory pain produces mu opioid receptor (MOR) desensitization and/or a reduction in its levels in the mesocorticolimbic system (MCLS;Ozaki et al., 2002;Zubieta et al., 2001). Interestingly, rats presenting inflammatory pain needed higher doses of heroin to