Investigating the Effect of Zinc Supplementation on Probability of Relapse and Mental Health in Patients with Substance Abuse Disorder Undergoing Methadone Maintenance Treatment

Background: Considering different factors such as high withdrawal rates in methadone maintenance treatment (MMT) programs alongside mental health (MH) problems appearing in patients with substance abuse disorder and the lack of prior research on the effect of zinc supplementation in this respect, the present study aimed to investigate the effect of zinc supplementation on probability of relapse (PoR) and MH problems in patients with substance abuse disorder undergoing MMT. Methods: For this purpose, a randomized controlled trial with a clinical basis was fulfilled on a total of 68 patients with substance abuse disorder receiving MMT, allocated to two groups, viz. intervention and control (each one consisting of 34 individuals). Then, the participants in the intervention group were given zinc supplements combined with methadone for three months and the controls only took methadone, according to the treatment plan. The data were collected using the Relapse Prediction Scale (RPS) and the Depression, Anxiety and Stress Scale 21 (DASS-21) before, one month after, and at the end of the intervention program. Findings: Compared to the control group, PoR (p=0.01), drug craving (p=0.002), and the RPS total score (p=0.002) in the intervention group were significantly lower. Moreover, the results revealed a significant decreasing trend in depression (p=0.01), anxiety (p<0.001), stress (p = 0.001), and the DASS-21 total score (p=0.001) in the intervention. Compared to the control group, the DASS-21 total score (p<0.001) in the intervention group were significantly lower. Conclusion: Accordingly, it was concluded that zinc supplementation could reduce the PoR and improve MH problems in patients with substance abuse disorder experiencing MMT. However, further research is recommended to fill the gaps. Trial Registration The research protocol has been also listed on the Iranian Registry of Clinical Trials (IRCT) with the code no. IRCT2020050904736N1