No abstract

Transcranial direct current stimulation (tDCS) is a selective, painless, brain stimulation technique that allows the electric stimulation of specific cortical regions. TDCS has been recently used as investigational intervention for major depression and treatment resistant depression (TRD) with encouraging results. The present study was aimed to investigate the efficacy and tolerability of tDCS in major depressives with poor response to pharmacological treatment. Twenty-three depressed patients, with a diagnosis of major depressive disorder or bipolar disorder, were treated with augmentative tDCS for 5 days, two sessions per day in a blind-rater trial. The course of depressive symptoms was analyzed using repeated measures ANOVA for HAM-D and MADRS total scores. A qualitative analysis on the basis of the HAM-D response was performed as well. Both analyses were conducted at three time-points: T0 (baseline), T1 (endpoint tDCS) and T2 (end of the first week of follow-up). All patients completed the trial without relevant side-effects. A significant reduction of HAM-D and MADRS total scores was observed during the study (P<0.0001). Treatment response (endpoint HAM-D reduction ≥50%) was obtained by four patients (17.4%) at T1 and by seven patients (30.4%) at T2 and remission (endpoint HAM-D<8) by three patients (13.0%) at T1 and by four subjects (17.4%) at T2. Present findings support the efficacy and good tolerability of tDCS in the acute treatment of patients with TRD with clinical benefit being progressive and extended to the first week of follow-up. Further sham-controlled trials with longer follow-up are needed to confirm present results.

Bipolar disorder (BD) is a chronic and highly disabling mood disorder, associated with the highest suicide rate among psychiatric disorders. Even though neurobiological bases of BD have still to be further elucidated, recent neuroimaging studies provided compelling evidence about functional correlates of cognitive deficits in BD patients, with working memory (WM) impairment being one of the most commonly reported findings. Such dysfunctions are likely to persist beyond acute phases of the illness, so they qualify as endophenotypic markers for the disorder. This review sought to synthesize, through a MEDLINE search up to December 2012, published functional magnetic resonance imaging (fMRI) studies on WM networks, conducted through N-back task in euthymic BD I patients and including a control comparison group. Eight studies meeting the search criteria were identified. Despite heterogeneity across findings, particularly in relation to task performance (i.e. accuracy and reaction time), most studies reported a loss of connectivity in BD patients' prefrontal networks, traditionally involved in WM, as well as patterns of abnormal activation in the dorso/ventrolateral prefrontal cortex, other prefrontal areas and the parietal and temporal cortex. These findings suggest the involvement of intact secondary systems in order to overcome lack of integrity across WM circuits in BD patients. Further investigation in the field is warranted.