Background: Transcranial direct current stimulation (tDCS) opens new perspectives in the treatment of major depressive disorder (MDD), because of its ability to modulate cortical excitability and induce long-lasting effects. The aim of this review is to summarize the current status of knowledge regarding tDCS application in MDD. Methods: In this review, we searched for articles published in PubMed/MEDLINE from the earliest available date to February 2018 that explored clinical and cognitive effects of tDCS in MDD. Results: Despite differences in design and stimulation parameters, the examined studies indicated beneficial effects of tDCS for MDD. These preliminary results, the non-invasiveness of tDCS, and its good tolerability support the need for further research on this technique. Conclusions: tDCS constitutes a promising therapeutic alternative for patients with MDD, but its place in the therapeutic armamentarium remains to be determined.

Clear guidance for successive antidepressant pharmacological treatments for non-responders in major depression is not well established. Based on the RAND/UCLA Appropriateness Method, the French Association for Biological Psychiatry and Neuropsychopharmacology and the fondation FondaMental developed expert consensus guidelines for the management of treatment-resistant depression. The expert guidelines combine scientific evidence and expert clinicians’ opinions to produce recommendations for treatment-resistant depression. A written survey comprising 118 questions related to highly-detailed clinical presentations was completed on a risk-benefit scale ranging from 0 to 9 by 36 psychiatrist experts in the field of major depression and its treatments. Key-recommendations are provided by the scientific committee after data analysis and interpretation of the results of the survey. The scope of these guidelines encompasses the assessment of pharmacological resistance and situations at risk of resistance, as well as the pharmacological and psychological strategies in major depression. The expert consensus guidelines will contribute to facilitate treatment decisions for clinicians involved in the daily assessment and management of treatment-resistant depression across a number of common and complex clinical situations.

Recommendations for pharmacological treatments of major depression with specific comorbid psychiatric conditions are lacking. The French Association for Biological Psychiatry and Neuropsychopharmacology and the fondation FondaMental developed expert consensus guidelines for the management of depression based on the RAND/UCLA Appropriatneness Method. Recommendations for lines of treatment are provided by the scientific committee after data analysis and interpretation of the results of a survey of 36 psychiatrist experts in the field of major depression and its treatments. The expert guidelines combine scientific evidence and expert clinician’s opinion to produce recommendations for major depression with comorbid anxiety disorders, personality disorders or substance use disorders and in geriatric depression. These guidelines provide direction addressing common clinical dilemmas that arise in the pharmacologic treatment of major depression with comorbid psychiatric conditions.

Dynamic and temporal facets of the various constructs that comprise motivation remain to be explored. Here, we adapted the Effort Expenditure for Reward Task, a well-known laboratory task used to evaluate motivation, to study the event-related potentials associated with reward processing. The Stimulus Preceding Negativity (SPN) and the P300 were utilized as motivation indicators with high density electroencephalography. The SPN was found to be more negative for difficult choices compared to easy choices, suggesting a greater level of motivation, at a neurophysiological level. The insula, a structure previously associated with both effort discounting and prediction error, was concomitantly activated during the generation of the SPN. Processing a gain significantly altered the amplitude of the P300 compared to an absence of gain, particularly on centroparietal electrodes. One of the generators of the P300 was located on the vmPFC, a cerebral structure involved in the choice between two positive results and their predictions, during loss processing. Both the SPN and the P300 appear to be reliable neural markers of motivation. We postulate that the SPN represents the strength of the motivational level, while the P300 represents the impact of motivation on updating memories of the feedback.

The aim of the present study was to investigate the relationship between trait impulsivity, risk-taking, and decision-making performance. We recruited 20 healthy participants who performed the Iowa Gambling Task (IGT) and the Balloon Analog Risk Task (BART) to measure decision-making and risk-taking. The impulsivity was measured by the Barratt Impulsiveness Scale. Resting-state neural activity was recorded to explore whether brain oscillatory rhythms provide important information about the dispositional trait of impulsivity. We found a significant correlation between the ability to develop a successful strategy and the propensity to take more risks in the first trials of the BART. Risk-taking was negatively correlated with cognitive impulsivity in participants who were unable to develop a successful strategy. Neither risk-taking nor decision-making was correlated with cortical asymmetry. In a more exploratory approach, the group was sub-divided in function of participants’ performances at the IGT. We found that the group who developed a successful strategy at the IGT was more prone to risk, whereas the group who failed showed a greater cognitive impulsivity. These results emphasize the need for individuals to explore their environment to develop a successful strategy in uncertain situations, which may not be possible without taking risks.

Impulsivity is a core feature of borderline personality disorder (BPD) and is closely related to suicide risk and destructive and aggressive behaviors. Although transcranial direct current stimulation (tDCS) has shown its promising effects as an intervention to modulate impulsivity, no study has explored its potential regarding BPD. This is a multicenter, crossover, double-blind study comparing active versus sham tDCS (2 mA, 30 min), applied over the dorsolateral prefrontal cortex for five consecutive days in 50 BPD patients. Participants will be assessed for impulsivity, depressive symptoms, and suicide risk. The main efficacy criteria on reduction of impulsivity will be the amplitude variation of one specific evoked potential detected by electroencephalography (EEG) during the balloon analogue risk task. Baseline measures will be compared to scores obtained immediately after sessions, then 12 and 30 days later. This study investigates the safety and effects of tDCS, which may have a significant impact on impulsivity in patients with BPD and may be useful to reduce risky behaviors. ClinicalTrials.gov, NCT03498937 . Registered on 17 April 2018.