Transcranial direct current stimulation for the treatment of Major Depressive Disorder : a summary of preclinical, clinical and translational findings

Major depressive disorder (MDD) is a common psychiatric illness, with 6-12% lifetime prevalence. It is also among the five most disabling diseases worldwide. Current pharmacological treatments, although relatively effective, present important side effects that lead to treatment discontinuation. Therefore, novel treatment options for MDD are needed. Here, we discuss the recent advancements of one new neuromodulatory technique - transcranial direct current stimulation (tDCS) - that has undergone intensive research over the past decade with promising results. tDCS is based on the application of weak, direct electric current over the scalp, leading to cortical hypo- or hyper-polarization according to the specified parameters. Recent studies have shown that tDCS is able to induce potent changes in cortical excitability as well as to elicit long-lasting changes in brain activity. Moreover, tDCS is a technique with a low rate of reported side effects, relatively easy to apply and less expensive than other neuromodulatory techniques - appealing characteristics for clinical use. In the past years, 4 of 6 phase II clinical trials and one recent meta-analysis have shown positive results in ameliorating depression symptoms. tDCS has some interesting, unique aspects such as noninvasiveness and low rate of adverse effects, being a putative substitutive/augmentative agent for antidepressant drugs, and low-cost and portability, making it suitable for use in clinical practice. Still, further phase II and phase III trials are needed as to better clarify tDCS role in the therapeutic arsenal of MOD

Viewing Nature Scenes Positively Affects Recovery of Autonomic Function Following Acute-Mental Stress

A randomized crossover study explored whether viewing different scenes prior to a stressor altered autonomic function during the recovery from the stressor. The two scenes were (a) nature (composed of trees, grass, fields) or (b) built (composed of man-made, urban scenes lacking natural characteristics) environments. Autonomic function was assessed using noninvasive techniques of heart rate variability; in particular, time domain analyses evaluated parasympathetic activity, using root-mean-square of successive differences (RMSSD). During stress, secondary cardiovascular markers (heart rate, systolic and diastolic blood pressure) showed significant increases from baseline which did not differ between the two viewing conditions. Parasympathetic activity, however, was significantly higher in recovery following the stressor in the viewing scenes of nature condition compared to viewing scenes depicting built environments (RMSSD; 50.0 ± 31.3 vs 34.8 ± 14.8 ms). Thus, viewing nature scenes prior to a stressor alters autonomic activity in the recovery period. The secondary aim was to examine autonomic function during viewing of the two scenes. Standard deviation of R-R intervals (SDRR), as change from baseline, during the first 5 min of viewing nature scenes was greater than during built scenes. Overall, this suggests that nature can elicit improvements in the recovery process following a stressor. © 2013 American Chemical Society

Negative life events and migraine: a cross-sectional analysis of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) baseline data

Abstract\ud \ud Background\ud Stress is a typical migraine trigger. However, the impact of negative life events on migraine activity is poorly studied. The aim of this study is to investigate the association between negative life events and migraine using data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) baseline assessment.\ud \ud \ud Methods\ud ELSA-Brasil is a multicenter cohort study conducted in six Brazilian cities. Baseline assessment included validated questionnaires for headache classification and the occurrence of five pre-specified negative life events (financial hardship, hospitalization other than for childbirth, death of a close relative, robbery and end of a love relationship), focusing on a 12-month period before evaluation. We built crude and adjusted logistic regression models to study the association between the occurrences of negative life events and migraine diagnosis and activity.\ud \ud \ud Results\ud We included 4,409 individuals with migraine and 4,457 participants without headache (reference). After adjustment for age, sex, race, income and educational level, we found that the occurrence of a negative life event (Odds ratio = 1.31; 95% confidence interval = 1.19 – 1.45) was associated with migraine. However, after stratifying with subgroup analyses, only financial hardship (Odds ratio = 1.65; 95% confidence interval = 1.47 – 1.87) and hospitalization (Odds ratio = 1.47; 95% confidence interval = 1.25 – 1.72) were independently associated with migraine. Further adjustment for a current major depression episode and report of religious activity did not significantly change the results. Considering migraine frequency as (a) less than once per month, (b) once per month to once per week, or (c) more than once per week, financial hardship and hospitalization remained significantly associated with migraine in all episode frequency strata, with higher odds ratios for higher frequencies in adjusted models. We also observed a significant association between the death of a close relative and the highest migraine frequency stratum (Odds ratio = 1.38; 95% confidence interval = 1.09 – 1.75) in full-adjusted model.\ud \ud \ud Conclusions\ud The occurrence of financial hardship and hospitalization had a direct and independent association with migraine diagnosis and frequency. The death of a close relative was also independently associated with the highest migraine frequency stratum.Brazilian Ministry of Health (Science and Technology Department)Brazilian Ministry of Science and Technology (Financiadora de Estudos e\ud Projetos and CNPq National Research Council) (grants 01 06 0010.00 RS, 0106 0212.00 BA, 01 06 0300.00 ES, 01 06 0278.00 MG, 01 06 0115.00 SP, 01 060071.00 RJ

Common mental disorders and sociodemographic characteristics: baseline findings of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Objective: To assess the prevalence of common mental disorders (CMD) and the association of CMD with sociodemographic characteristics in the Brazilian Longitudinal Study of Adult Health (ELSABrasil) cohort. Methods: We analyzed data from the cross-sectional baseline assessment of the ELSA-Brasil, a cohort study of 15,105 civil servants from six Brazilian cities. The Clinical Interview Schedule-Revised (CIS-R) was used to investigate the presence of CMD, with a score X 12 indicating a current CMD (last week). Specific diagnostic algorithms for each disorder were based on the ICD-10 diagnostic criteria. Prevalence ratios (PR) of the association between CMD and sociodemographic characteristics were estimated by Poisson regression. Results: CMD (CIS-R score X 12) was found in 26.8% (95% confidence intervals [95%CI] 26.1-27.5). The highest burden occurred among women (PR 1.9; 95%CI 1.8-2.0), the youngest (PR 1.7; 95%CI 1.5-1.9), non-white individuals, and those without a university degree. The most frequent diagnostic category was anxiety disorders (16.2%), followed by depressive episodes (4.2%). Conclusion: The burden of CMD was high, particularly among the more socially vulnerable groups. These findings highlight the need to strengthen public policies aimed to address health inequities related to mental disorders

Beyond the target area: an integrative view of tDCS-induced motor cortex modulation in patients and athletes

Transcranial Direct Current Stimulation (tDCS) is a non-invasive technique used to modulate neural tissue. Neuromodulation apparently improves cognitive functions in several neurologic diseases treatment and sports performance. In this study, we present a comprehensive, integrative review of tDCS for motor rehabilitation and motor learning in healthy individuals, athletes and multiple neurologic and neuropsychiatric conditions. We also report on neuromodulation mechanisms, main applications, current knowledge including areas such as language, embodied cognition, functional and social aspects, and future directions. We present the use and perspectives of new developments in tDCS technology, namely high-definition tDCS (HD-tDCS) which promises to overcome one of the main tDCS limitation (i.e., low focality) and its application for neurological disease, pain relief, and motor learning/rehabilitation. Finally, we provided information regarding the Transcutaneous Spinal Direct Current Stimulation (tsDCS) in clinical applications, Cerebellar tDCS (ctDCS) and its influence on motor learning, and TMS combined with electroencephalography (EEG) as a tool to evaluate tDCS effects on brain function