Table 1.

Recommendations to advance research on the positive affective/reward mechanisms of psychosocial interventions for chronic pain and opioid misuse.

Recommendation	Detail
Dismantle effects of various techniques	Studies should optimize the next generation of psychosocial pain therapies by using micro RCTs and factorial designs (e.g., multiphase optimization strategy) to determine the independent and interactive effects of an array of techniques for stimulating the reward system.
Quantify the phenomenological and physiological experience of pleasure as a mediator of treatment outcomes	Studies should quantify and examine interoceptive awareness of pleasure elicited by psychosocial interventions as a mediator of treatment outcomes.
Employ biobehavioral measures of reward processing	Studies should employ behavioral (e.g., eye-tracking) and neuroimaging (e.g., fMRI) measures to assess effects of psychosocial intervention on reward processing of exteroceptive stimuli, and whether increased reward responsiveness predicts reduced pain and opioid (mis)use.
Decipher intervention-induced dynamics of change	Studies should employ high-density ecological momentary assessments (EMA) of positive emotions, savoring, reappraisal, and other processes to analyze complex chains of causes and effects that synergistically emerge during chronic pain treatment.
Use placebo controls	Studies should use sham intervention arms (e.g., sham mindfulness [112]) to parse effects of expectancy and social desirability from mechanisms of action.
Determine the duration of effects on reward system function	Studies should collect longitudinal data to ascertain the duration of psychosocial intervention effects on reward-related mechanisms, and to determine whether such interventions can overcome the hedonic treadmill effect [12] to produce trait-like changes in the propensity towards positive affective states.
Experimentally stimulate meaning and self-transcendence	With the re-emergence of psychedelic research, pharmacological probes to reliably stimulate meaning and self-transcendent states are becoming available [49]. Studies with psychedelics, alone or in combination with psychosocial interventions like MBIs, may test whether self-transcendent experiences produce relief of pain and opioid craving by modulating reward system function.