Although 85% of inpatients with Borderline Personality Disorder (BPD) receive psychotropic drug treatment, no drug is approved for this indication so far. A dysregulation of the endogenous opioid system (EOS) has been posed to underly the neurobiology of BPD. Accordingly, the opioid antagonist naltrexone might be helpful to treat symptoms of BPD. Two small studies showed limited differences of naltrexone vs. placebo on dissociation, which were not significant, perhaps due to the low power of the studies:

Naltrexone was administered in treatment-refractory patients with BPD in a university department of psychiatry. This study aimed to assess the relative contribution of naltrexone and other psychopharmacological drugs to the improvement of overall symptomatology in patients with BPD.

A retrospective analysis of the charts of inpatients (n=161) with BPD was performed. Patients were classified as either treatment responders or non-responders. As all patients received multiple psychopharmacological treatments, stepwise logistic regression analysis was performed to detect, which drug contributed most to improvement of symptomatology.

None of the drugs applied contributed significantly to improvement, with the exception of naltrexone (odds ratio, p=2,9) Patients treated with naltrexone (n=55, 34,16%) recovered significantly more often and faster and, in particular, showed highly significant reduction of self-harm and suicidal thoughts. Higher doses of naltrexone treatment were more effective than low-dose treatment; however, the latter was still better than any other treatment.

Large-scale double-blind studies are warranted to examine the efficacy of opioid antagonists (naltrexone, nalmefene) in BPD.