Search

Introduction: Drug craving is a major problem in addiction treatment. Neuroimaging research has revealed various areas for drug craving, among which two key areas are the Dorsolateral Prefrontal Cortex (DLPFC) and the cerebellum. The DLPFC is involved in different cognitive tasks, such as inhibitory control over seductive options that promise an immediate reward. The cerebellum is related to cognition and memory and activated by drug-related cues. Therefore, we decided to study the effect of Transcranial Direct Current Stimulation (tDCS) on six different protocols in reducing drug craving and increasing cognitive functions in methamphetamine addicts. Methods: The present study is quasi-experimental, with a pre-test-post-test design and a control group. Based on a simple sampling method, 15 male methamphetamine addicts were recruited from two rehabilitation centers in Tehran City, Iran. The participants were aged 18-65 years with a minimum of 12-month history of methamphetamine dependence. The Visual Analog Scale (VAS), the go/no-go task and the n-back task were administered before and after a single session of tDCS. The tDCS was applied on six protocols: 1) the right DLPFC anodal and the left DLPFC cathodal stimulation, 2) the right DLPFC cathodal and the left DLPFC anodal stimulation, 3) the right DLPFC anodal and the right arm cathodal stimulation, 4) the left DLPFC anodal and the left arm cathodal stimulation, 5) the right cerebellar hemisphere (O2) anodal and the left cerebellar hemisphere (O1) cathodal stimulation, and 6) the right cerebellar hemisphere (O2) cathodal and the left cerebellar hemisphere (O1) anodal stimulation. The data were analyzed by covariance method using SPSS software v. 22. Results: Study results indicated that while single-session tDCS effects on craving were not significant, it increased cognitive inhibition, especially in protocol 2: the right DLPFC cathodal and the left DLPFC anodal stimulation. Conclusion: Single-session tDCS affects craving insignificantly, but it can increase cognitive inhibition significantly. These findings support the results of previous studies on the effects of brain stimulation on reducing drug craving in other drug-type settings. [ABSTRACT FROM AUTHOR]

Obsessive-Compulsive Disorder (OCD) is one disabling psychiatric condition. Investigations reported the effectiveness of trans-cranial direct current stimulation (tDCS) in regulating orbito-fronto-striato-pallido-thalamic network activity in OCD patients. In these patients, hypo- or hyper-activity of different brain areas including orbitofrontal cortex (OFC), pre-supplementary motor area (pre-SMA), cingulate gyrus, putamen, thalamus, parietal cortex and cerebellum have been reported.The purpose of this study is determination the efficacy of three different tDCS protocols and finding the best one to mitigate OCD symptoms. This study was a quasi-experimental research with pre-test-post-test and a one-month follow-up. Of the patients that referred to Brain and Cognitive Clinic in Tehran, 40 OCD subjects were randomly selected and assigned into four groups (three experimental groups and one control group). Of the mentioned patients, those who scored 16 or above on the Yale-Brown obsessive-compulsive scale were chosen. tDCS was delivered over a period of 5 days at an intensity of 2 mA for 15 minutes twice a day. In the three intervention groups, tDCS was delivered in one of the following electrode montages: (i) anode over the right cerebellum (O2) and cathode over the supplementary motor area (pre-SMA; c3/c4); (ii) anode over O2 and cathode over the left OFC (FP1); or (iii) anode over O2 and cathode over the left cerebellum (O1). The control group received sham stimulation (anode over O2 and cathode over the left FP1). Analysis of covariance (ANCOVA) was used to evaluate the results. The results showed that two of the tDCS protocols reduced OCD symptoms (P < 0.001). Data also revealed that the effect of the anodal stimulation of the O2 led to better outputs as compared to O1.. [ABSTRACT FROM AUTHOR]

Objective: Stuttering is a neurodevelopmental condition affecting 5% of children. Developmental stuttering disrupts the smooth flow of speech, resulting in characteristic speech disfluencies. Anxiety is one of the most widely observed and extensively studied psychological concomitants of stuttering. Recently, it has been shown that noninvasive brain stimulation may be useful in enhancing the results of fluency interventions in people who stutter. The present study aimed to examine whether the severity of stuttering and anxiety was affected by transcranial direct current stimulation in children who stutter Methods: This study is a clinical trial study in which the statistical community includes schoolaged children in Tehran who were referred to psychological clinics for treatment. Twentytwo children with stuttering were randomly assigned in two groups. Eleven children in the experimental group would receive real transcranial direct current stimulation, and 11 children in the control group were exposed to sham stimulation. The experimental group received 20 min of 2-mA anodal stimulation in 15 sessions in three weeks. The severity of stuttering and anxiety was assessed before and after the last session and then 1 and 6 weeks after the intervention. Results: The severity of stuttering and anxiety in both groups were similar before the intervention (P>0.05). A significant decrease in the severity of stuttering and anxiety at the end of the intervention and 1 and 6 weeks after the intervention occurred in the experimental group (P<0.05), while the control group did not show any significant change. Conclusion: The results indicated that stuttering severity and anxiety were ameliorated by transcranial direct current stimulation immediately after the intervention and at 1 and 6 weeks follow-up. [ABSTRACT FROM AUTHOR]