RAPID AND SUSTAINED IMPROVEMENT OF RESIDUAL ANHEDONIA SYMPTOMS IN PATIENTS WITH DEPRESSION USING ANALGESIC AGENT - DEZOCINE

Abstract Background Studies suggest anhedonia afflicts 50-80% of depressive cases, correlating with exacerbated morbidity and elevated suicidality. While monoaminergic antidepressants are the first-line treatment of choice for MDD, their impact on anhedonia is limited, underscoring the absence of efficacious, rapid interventions targeting this symptomatology. Accumulating research suggests that opioid drugs may alleviate symptoms of depression and anhedonia. Dezocine, a synthetic opioid akin to benzomorphan opioids like pentazocine, is a partial agonist/antagonist at μ- and κ-opioid receptors. Additionally, dezocine acts as an inhibitor of both the norepinephrine transporter (NET) and the serotonin transporter (SERT), curtailing the reuptake of respective neurotransmitters. Despite its established analgesic use, dezocine’ s antidepressant possibilities have been minimally investigated. Objectives This study aims to discuss the antidepressant effects of dezocine, as well as its potential for ameliorating symptoms of anhedonia, through the integration of a case report. Method Without altering the patient’ s original treatment regimen (continued administration of sustained-release bupropion 150 mg, once daily, and clonazepam 15 mg, once nightly), a single low dose (0.1 mg/kg, administered over 30 minutes) of dezocine was intravenously infused. A baseline assessment of the patient was conducted one week prior to receiving dezocine, followed by a 4-week follow-up. The Hamilton Depression Rating Scale (HAMD-17), Montgomery-Asberg Depression Rating Scale (MADRS), as well as the self-rating scales, the Patient Health Questionnaire-9 (PHQ-9) and Dimensional Anhedonia Rating Scale (DARS) were utilized for evaluation. Results One week prior to the administration of dezocine, the patient scored 4 and 5 on item 8 of MADRS and item 7 of HAMD-17, respectively. The score on item 1 of PHQ-9 was 3. The scores on the various dimensions of DARS were 3, 4, 4, and 6, with a total score of 17, indicating mild anhedonia symptoms. Following dezocine infusion, the patient exhibited significant improvement in anhedonia symptoms at the end of the 1st, 2nd, and 3rd weeks (DARS total scores of 52, 49, and 35, respectively). By the end of the 4th week post-infusion, the patient’ s anhedonia symptoms gradually became more prominent, but still showed improvement compared to the baseline (DARS total score of 29). Discussion and Conclusion The antidepressant and anhedonia- improving effects of dezocine may be related to its mechanism of action, although the possibility of a placebo effect cannot be ruled out. Currently, it is still unclear whether dezocine exerts an adjunctive therapeutic effect or has inherent therapeutic properties. High-quality clinical and basic research is needed to further explore this. Nevertheless, regardless of these factors, the potential role of dezocine in the treatment of depression should be emphasized based on its pharmacological mechanism of action.