Psychological intervention combined with direct electrical brain stimulation (PIN-CODES) for treating major depression: A pre-test, post-test, follow-up pilot study

Transcranial direct current stimulation alters the process of reward processing in children with ADHD: Evidence from cognitive modeling

BACKGROUND

The ventromedial prefrontal cortex (vmPFC) and dorsolateral prefrontal cortex (dlPFC) are the neural underpinnings of reward processing, which is impaired in individuals with attention deficit hyperactivity disorder (ADHD). In the present study, we aimed to explore the impact of the vmPFC and the dlPFC regulation on reward processing.

METHODS

Twenty-six children with ADHD performed the balloon analogue risk-taking task (BART) and chocolate delay discounting task (CDDT) during five different sessions of transcranial direct current stimulation (tDCS), separated by a one-week interval: anodal left dlPFC/cathodal right vmPFC, the reversed electrode positioning, anodal left dlPFC stimulation with extracranial return electrode, anodal right vmPFC stimulation with extracranial return electrodes, and sham stimulation. Four-parameter and constant-sensitivity models were used to model the data.

RESULTS

In the BART, anodal dlPFC/cathodal vmPFC stimulation facilitated conservative decision making, anodal tDCS over dlPFC with extracranial return electrode increased positive beliefs about the explosion of a balloon, and anodal vmPFC/cathodal dlPFC stimulation reduced ongoing learning in the process of decision making. In the CDDT, anodal vmPFC stimulation with extracranial return electrode decreased impatience in the process of the task.

CONCLUSION

These results suggest a role of the left dlPFC and right vmPFC in the outcome of decision making and the process of risky decision making and delay discounting.

A transdiagnostic meta-analysis of acute augmentations to psychological therapy

At least half of all patients with mental health disorders do not respond adequately to psychological therapy. Acutely enhancing particular biological or psychological processes during psychological therapy may improve treatment outcomes. However, previous studies are confined to specific augmentation approaches, typically assessed within single diagnostic categories. Our objective was to assess to what degree acute augmentations of psychological therapy reduce psychiatric symptoms and estimate effect sizes of augmentation types (for example, brain stimulation or psychedelics). We searched Medline, PsycINFO and Embase for controlled studies published between database inception and 25 May 2022. We conducted a preregistered random-effects meta-analysis (PROSPERO CRD42021236403). We identified 108 studies (N = 5,889). Acute augmentation significantly reduced the severity of mental health problems (Hedges' g = -0.27, 95% CI: [-0.36, -0.18]; P < 0.0001), particularly for the transdiagnostic dimensions 'Fear' and 'Distress'. This result survived a trim-and-fill analysis to account for publication bias. Subgroup analyses revealed that pharmacological, psychological and somatic augmentations were effective, but to varying degrees. Acute augmentation approaches are a promising route to improve outcomes from psychological therapy.

Improved Executive Functions and Reduced Craving in Youths with Methamphetamine Addiction: Evidence from Combined Transcranial Direct Current Stimulation with Mindfulness Treatment

Objective

Transcranial direct current stimulation (tDCS) and mindfulness practices have been proposed as a potential approach to improve executive functions (EFs) and reduce craving in persons with substance use disorders. Based on the neural mechanisms of action of each of these interventions, the combination of both non-pharmacological interventions might have additive effects. In the current study, the effects of tDCS combined with mindfulness-based substance abuse treatment (MBSAT) to improve EFs and reduce craving were investigated in early abstinent methamphetamine abuse.

Methods

Eighty (youths aged between 18 and 21) early-abstinent methamphetamine users were randomly assigned to the research groups (tDCS group [n = 20], mindfulness group [n = 20], combined mindfulness-tDCS group [n = 20], and sham group [n = 20]). Active tDCS (1.5 mA,20 min, 12 sessions) or sham tDCS was appliedover the left dorsolateral prefrontal cortex and the MBSAT protocol was used over twelve 50-min sessions.

Results

Both in the post-test phase (immediately after the intervention) and follow-up phase (one month after the intervention), performance in most EFs tasks significantly improved in the combination group which received real tDCS ＋ MBSAT, as compared to baseline values and sham stimulation group. Similarly, a significant reduction in craving was observed after intervention inall treatment groups, but not the sham stimulation group. Interestingly, the increase in EFs and the reduction in craving post versus pre tDCS ＋ MBSAT intervention were correlated.

Conclusion

Findings from the current study provide initial support for the clinical effectiveness of combination tDCS ＋ MBSAT, possibly influencing cognitive/affective processes.

The effect of transcranial direct stimulation as an add-on treatment to conventional physical therapy on pain intensity and functional ability in individuals with knee osteoarthritis: A randomized controlled trial

OBJECTIVE

To investigate the effect of adding transcranial direct current stimulation (tDCS) to conventional physiotherapy treatment (PT) on pain and performance of individuals with knee osteoarthritis (KOA).

METHODS

Eighty people suffering from chronic KOA participated in this study. They were randomly divided into four treatment groups, including PT combined with tDCS over the primary motor cortex (M1), PT combined with tDCS over the primary sensory cortex (S1), PT combined with tDCS over the dorsolateral prefrontal cortex (DLPFC), and PT combined with sham tDCS. A visual analog scale (VAS) for pain intensity, the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire for knee-related disability, and several performance tests (stepping 15 s, chair stand test in 30 s, and walking 4 × 10 m) were used for assessment following 10 sessions of tDCS (T1), and one month after the last session of tDCS (T2).

RESULTS

Differential effects on pain intensity, knee-related disability, and performance were found between groups. Compared to sham tDCS: (i) tDCS over M1 improved VAS pain score, KOOS disability score, and performance tests at T1 and T2; (ii) tDCS over S1 improved VAS pain score at T1 and T2 and KOOS disability score and performance tests at T2; (iii) tDCS over the DLPFC improved VAS pain score at T1 and performance tests at T1 and T2.

CONCLUSION

tDCS could be a beneficial add-on treatment to conventional PT for pain relief, disability reduction and functional improvement in patients with KOA.

The role of dorsolateral and ventromedial prefrontal cortex in the processing of emotional dimensions

The ventromedial and dorsolateral prefrontal cortex are two major prefrontal regions that usually interact in serving different cognitive functions. On the other hand, these regions are also involved in cognitive processing of emotions but their contribution to emotional processing is not well-studied. In the present study, we investigated the role of these regions in three dimensions (valence, arousal and dominance) of emotional processing of stimuli via ratings of visual stimuli performed by the study participants on these dimensions. Twenty- two healthy adult participants (mean age 25.21 ± 3.84 years) were recruited and received anodal and sham transcranial direct current stimulation (tDCS) (1.5 mA, 15 min) over the dorsolateral prefrontal cortex (dlPFC) and and ventromedial prefrontal cortex (vmPFC) in three separate sessions with an at least 72-h interval. During stimulation, participants underwent an emotional task in each stimulation condition. The task included 100 visual stimuli and participants were asked to rate them with respect to valence, arousal, and dominance. Results show a significant effect of stimulation condition on different aspects of emotional processing. Specifically, anodal tDCS over the dlPFC significantly reduced valence attribution for positive pictures. In contrast, anodal tDCS over the vmPFC significantly reduced arousal ratings. Dominance ratings were not affected by the intervention. Our results suggest that the dlPFC is involved in control and regulation of valence of emotional experiences, while the vmPFC might be involved in the extinction of arousal caused by emotional stimuli. Our findings implicate dimension-specific processing of emotions by different prefrontal areas which has implications for disorders characterized by emotional disturbances such as anxiety or mood disorders.

Bifrontal high-frequency transcranial random noise stimulation is not effective as an add-on treatment in depression

BACKGROUND

Depressive disorders are linked to dysfunction in prefrontal cortical areas. Hence, non-invasive neurostimulation of the prefrontal cortex has demonstrated antidepressant efficacy. In the present study, we investigated the efficacy of high frequency transcranial random noise stimulation (hf-tRNS) as an add-on treatment for depression in a sham-controlled randomized trial.

METHODS

Forty in-patients with depression were randomized and treated with real or sham hf-tRNS (100-650 Hz) with 0 mA offset. The electrodes were mounted over the left and right dorsolateral prefrontal cortex. The Hamilton Depression Rating Scale (primary outcome), the Major Depression Inventory, the Clinical Global Impression scale and the Global Assessment of Functioning scale were used for assessment at baseline, after 3 weeks of intervention (end of treatment), and 9 weeks after intervention. Safety parameters included cognitive functioning and reported side-effects.

RESULTS

Comparison of real and sham treatment at the planned interim analysis showed an amelioration of symptoms in both groups for all outcomes with numeric but not statistically significant superiority of the sham arm for the primary outcome. Thus, the study was terminated prematurely after an interim analysis. There were no systematic differences with respect to safety parameters.

LIMITATIONS

The negative finding might be related to the specific stimulation parameters used in this study.

CONCLUSIONS

Our study suggests that prefrontal hf-tRNS is safe but not effective as an add-on treatment of depression. The challenge for future studies employing transcranial electric stimulation remains to identify effective stimulation parameters for the treatment of depression.

Transcranial Direct Current Stimulation Improves Executive Dysfunctions in ADHD: Implications for Inhibitory Control, Interference Control, Working Memory, and Cognitive Flexibility

Objective: This study examined effects of transcranial direct current stimulation (tDCS) over the dorsolateral prefrontal cortex (DLPFC) and orbitofrontal cortex (OFC) on major executive functions (EFs), including response inhibition, executive control, working memory (WM), and cognitive flexibility/task switching in ADHD. Method: ADHD children received (a) left anodal/right cathodal DLPFC tDCS and (b) sham stimulation in Experiment 1 and (a) left anodal DLPFC/right cathodal OFC tDCS, (b) left cathodal DLPFC/right anodal OFC tDCS, and (c) sham stimulation in Experiment 2. The current intensity was 1 mA for 15 min with a 72-hr interval between sessions. Participants underwent Go/No-Go task, N-back test, Wisconsin Card Sorting Test (WCST), and Stroop task after each tDCS condition. Results: Anodal left DLPFC tDCS most clearly affected executive control functions (e.g., WM, interference inhibition), while cathodal left DLPFC tDCS improved inhibitory control. Cognitive flexibility/task switching benefited from combined DLPFC-OFC, but not DLPFC stimulation alone. Conclusion: Task-specific stimulation protocols can improve EFs in ADHD.

Transcranial Direct Current Stimulation in ADHD: A Systematic Review of Efficacy, Safety, and Protocol-induced Electrical Field Modeling Results

Transcranial direct current stimulation (tDCS) is a promising method for altering cortical excitability with clinical implications. It has been increasingly used in neurodevelopmental disorders, especially attention-deficit hyperactivity disorder (ADHD), but its efficacy (based on effect size calculations), safety, and stimulation parameters have not been systematically examined. In this systematic review, we aimed to (1) explore the effectiveness of tDCS on the clinical symptoms and neuropsychological deficits of ADHD patients, (2) evaluate the safety of tDCS application, especially in children with ADHD, (3) model the electrical field intensity in the target regions based on the commonly-applied and effective versus less-effective protocols, and (4) discuss and propose advanced tDCS parameters. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses approach, a literature search identified 14 empirical experiments investigating tDCS effects in ADHD. Partial improving effects of tDCS on cognitive deficits (response inhibition, working memory, attention, and cognitive flexibility) or clinical symptoms (e.g., impulsivity and inattention) are reported in 10 studies. No serious adverse effects are reported in 747 sessions of tDCS. The left and right dorsolateral prefrontal cortex are the regions most often targeted, and anodal tDCS the protocol most often applied. An intensity of 2 mA induced stronger electrical fields than 1 mA in adults with ADHD and was associated with significant behavioral changes. In ADHD children, however, the electrical field induced by 1 mA, which is likely larger than the electrical field induced by 1 mA in adults due to the smaller head size of children, was sufficient to result in significant behavioral change. Overall, tDCS seems to be a promising method for improving ADHD deficits. However, the clinical utility of tDCS in ADHD cannot yet be concluded and requires further systematic investigation in larger sample sizes. Cortical regions involved in ADHD pathophysiology, stimulation parameters (e.g. intensity, duration, polarity, and electrode size), and types of symptom/deficit are potential determinants of tDCS efficacy in ADHD. Developmental aspects of tDCS in childhood ADHD should be considered as well.

Transcranial direct current stimulation in attention-deficit hyperactivity disorder: A meta-analysis of neuropsychological deficits

Transcranial direct current stimulation (tDCS) is a promising method for altering cortical excitability with clinical implications in neuropsychiatric diseases. Its application in neurodevelopmental disorders especially attention-deficit hyperactivity disorder (ADHD), is in early stage and promising but its effectiveness has not been systematically examined yet. We conducted a meta-analysis on the effectiveness of tDCS on the most studied neuropsychological symptoms of ADHD, which is the first reported meta-analysis of tDCS studies on ADHD. Data from 10 randomized controlled studies (including 11 separate experiments) targeting inhibitory control, and/or working memory (WM) in ADHD were included. Results show that overall tDCS significantly improved inhibitory control. Sub-analyses further show that dorsolateral prefrontal cortex (dlPFC) (but not right inferior frontal gyrus) tDCS and anodal (but not cathodal) tDCS significantly improved inhibitory control with a small effect size. Anodal dlPFC-tDCS had the largest significant effect on inhibitory control with a small-to-medium effect size. Additionally, a significant improving effect of tDCS on inhibitory control accuracy (but not response time) and WM speed (but not accuracy) were found. Overall, this meta-analysis supports a beneficial effect of tDCS on inhibitory control and WM in ADHD with a small-to-medium effect size. TDCS seems to be a promising method for improving neuropsychological and cognitive deficits in ADHD. However, there might be a dissociation between neuropsychological deficits and clinical symptoms of ADHD and therefore, the significance of this meta-analysis for clinical purposes is limited. Future studies should systematically evaluate the role of inter-individual factors (i.e., ADHD subtype, types of the deficit) and stimulation parameters (i.e., site, polarity, intensity, duration, repetition rate) on tDCS efficacy in ADHD population and examine whether benefits are long-term.

Cognitive training for modifying interpretation and attention bias in depression: Relevance to mood improvement and implications for cognitive intervention in depression

Depressed individuals interpret ambiguous information more negatively and this has been suggested a central component in cognitive models of depression. In this study we investigated the effectiveness of the interpretation modification training on modifying interpretation bias in depression and its association with symptoms reduction. In a double-blind, randomized controlled design, twenty-two depressed individuals (mean age = 19.86, SD = 1.16) were randomly assigned to the experimental and control groups. They completed 10 sessions of cognitive training with the Ambiguous Hallmark Program (AHP) over 5 weeks. Participants' interpretation bias and their depressive scores were assessed and compared before and after the intervention. Results showed that the AHP significantly decreased negative interpretation in the experimental group. Additionally, a significant decrease in the depressive scores was also observed in the intervention group compared to the control group. We also observed the transfer of learning from the AHP training to another interpretation bias task. The AHP can significantly modify negative interpretations and symptoms in depression providing preliminary supporting evidence for its clinical application especially in mild-to-moderate depression. Improved cognitive control over emotional information and unbiased attention to them could explain effects of the Interpretation modification paradigm. Further studies need to examine the efficacy of the AHP as a potential cognitive intervention in depression.

Sleep-deprivation and autobiographical memory: evidence from sleep-deprived nurses

Negative effects of sleep deprivation on different types of memory are well documented, but the specific effects on autobiographical memory performance are not well studied. In this study, we investigated performance on the autobiographical memory test in a group of sleep-deprived and well-rested nurses. One-hundred participants divided into sleep-deprived (N = 50, 25 females) and well-rested (N = 50, 25 females) groups took part in the study. The sleep-deprived group included night-shift nurses with 8-12 hr sleep deprivation, while the well-rested group had the usual night sleep before performance assessment. All participants were matched for gender, age, education and employment status. They completed depression and anxiety inventories, and underwent the autobiographical memory test, which included 18 cue words with positive, negative and neutral valence. The sleep-deprived group scored significantly higher in depression scores. Analysis of covariance (ANCOVA) results showed that sleep-deprived participants had a significantly poorer autobiographical memory compared with the well-rested group. Additionally, specific memories were significantly declined in the sleep-deprived group. This group remembered significantly less positive and more negative memories. Findings implicate that sleep deprivation has detrimental effects on autobiographical memory specificity and valence, and is associated with mood dysregulation.

Clinical and demographic predictors of response to rTMS treatment in unipolar and bipolar depressive disorders

OBJECTIVE

Previous studies investigated predictors of repetitive transcranial magnetic stimulation (rTMS) response in depressive disorders but there is still limited knowledge about clinical predictors. Moreover, predictors of rTMS response in bipolar depression (BDD) are less studied than unipolar depression (UDD).

METHODS

We performed a binary logistic regression analysis in 248 patients with depressive disorders (unipolar N=102, bipolar N=146) who received 20 sessions of DLPFC rTMS (High-frequency rTMS, low-frequency rTMS, bilateral rTMS) to investigate significant clinical and demographic predictors of rTMS response. We also investigated effects of depression type, response (yes, no) and time on reducing somatic and cognitive-affective symptoms of patients.

RESULTS

Depression type (unipolar vs. bipolar) did not have a significant effect on rTMS response. 45% of all patients, 51.5% of UDD patients and 41% of BDD patients, responded to rTMS treatment. Age was the only significant demographic predictor of treatment response in all patients. Cognitive-affective symptoms, compared to somatic symptoms were significant predictors for treatment response to rTMS. Common and unique clinical predictor for UDD and BDD were identified.

CONCLUSIONS

Younger patients and those with cognitive-affective rather than somatic symptoms benefit more from DLPFC rTMS treatment. rTMS is effective in UDD and BDD patients. Patients should be selected based on clinical and demographic profile.

SIGNIFICANCE

Findings are based on the largest thus far reported sample of patients with depressive disorders that received DLPFC rTMS.