High dose naloxone in depression

The behavioral effects of a 2 mg/kg iv bolus infusion of naloxone were compared with a placebo infusion using a double-blind design in a small group of inpatient depressives (n = 6) and normals (n = 8). Naloxone produced consistent and significant worsening in the rated signs and subjective symptoms of depression in the patients. In the normals, lesser changes in Hamilton depression and BPRS total scores were observed while none of the subjective scales were significantly altered. The data suggest that depressives manifest a more marked and subjectively more intense response to naloxone compared to normals. Further studies are required to confirm this preliminary finding and to clarify its relationship to the pathogenesis of depression.