Naltrexone for Prolonged Grief Disorder

Inclusion Criteria: * 18 years of age or older. * Lives within a reasonable distance from NYPH for convenient clinic visits. * Can speak, read, and write English proficiently. * Meet diagnostic criteria for PGD based on the DSM guidelines * If a female patient, must agree to use a method of contraception and be willing and able to continue contraception during the first 8 weeks of the study while she is taking the study drug. Female patients who are planning to use oral hormonal contraception during this time must have initiated it at least 2 months prior to the baseline visit. * If a male patient, must agree to use a method of contraception and be willing and able to continue contraception during the first 8 weeks of the study while he is taking the study drug. Exclusion Criteria: • Having recently started taking/prescribed medications for any psychiatric illness (e.g. SSRIs for MDD) within the past 3 months; participants who have been taking this medication for longer than 3 months can be included. * Having recently started psychotherapy for any psychiatric illness within the past 3 months; participants who have been receiving psychotherapy for longer than 3 months can be included. * Prior history of recently active (e.g. within the past 3 months) opioid dependence. * Current prescription, non-prescription, or illicit opioid use, (i.e., acute use within the past 14 days or chronic use within the last 30 days), including opioid antagonists for alcohol or opioid dependen…