en Cellular and molecular Neuroscience Cellular and molecular Neuroscience Original Original <strong>Introduction: </strong>Addiction to opioids is a serious problem and concern in any nation today.&nbsp; Unfortunately, the rate of taking these drugs and addiction to them has drastically increased. This research aimed at the study of the degree of the BDNF serum level, reducing depression, stress and also studied the diminishing the craving by means of transcranial direct current stimulation (tDCS) in opioid abusing patients.<br> <strong>Method: </strong>The research method was a quasi-experimental design with a pre-post test administered on three groups. The statistical population included all addicted people to opioids in Zanjan. A sample of 30 patients was selected based on the DSM-5 diagnosing criteria through available sampling and then they were randomly placed into three groups of 10 people. After all the participants knowingly filled out the consent forms before performing an intervention, they were evaluated by ELISA technique to measure the serum level of BDNF, then a desires for drugs questionnaire (DDQ), depression, anxiety and stress scale (DASS) were administered. Then, for 10 sessions of 20 minutes, tDCS for the three groups, namely Group A (L-DLPFC) anodal left/catodal right, group B( R-DLPFC) anodal right/cathodal left, and group C (sham-tDCS) were administered. After the treatment, all the participants were reevaluated and then the data were analyzed by Kolmogorov- Smirnov test, one-way analysis of variance (ANOVA) and the Bonfreoni test.<br> <strong>Results</strong>: The results showed that stimulating the DLPFC led to a significant change in growing the level of BDNF (P= .031) and lowering the degree of depression (p= .018), anxiety (p= .001), stress (p= .012) and decreased the level of craving (p= .001) in opioid addicted patients. Moreover, the pair comparison indicated that group B showed a significant improvement versus group C.<br> <strong>Conclusion:</strong> The findings of this research suggest that TDCS is an effective and a complementary treatment, beside the common treatments of opioid abusing patients. Transcranial direct current stimulation, Craving, Opioid, Brain-derived neurotrophic factor, Depression dorsolateral prefrontal cortex, Anxiety 641 650 http://bcn.iums.ac.ir/browse.php?a_code=A-10-1710-1&slc_lang=en&sid=1 Zakaria Eskandari 13700319475328460026988 13700319475328460026988 No Department of Clinical Psychology and Addiction Studies, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran. Mohsen Dadashi psy.mohsen@gmail.com 13700319475328460026989 13700319475328460026989 Yes Department of Clinical Psychology, Social Determinants of Health Research Center, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran. Hossin Mostafavi 13700319475328460026990 13700319475328460026990 No Department of Physiology, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran. Alireza Armani Kia 13700319475328460026991 13700319475328460026991 No Department of Psychiatry, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran. Reza Pirzeh 13700319475328460026992 13700319475328460026992 No Department of Psychiatry, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran.