RecruitingDrug trialLow-Dose Naltrexone for the Treatment of Complex Regional Pain SyndromeThe investigators are testing treatment with low-dose naltrexone (LDN) for symptom relief of complex regional pain syndrome (CRPS). Study participants will be randomly assigned to receive either LDN or placebo for a period of several weeks. During this period participants will be asked to attend either in-person or virtual study visits and complete questionnaires.