Transcranial Direct Current Stimulation for Obsessive-Compulsive Disorder: A Systematic Review

Despite the advances in psychopharmacology and established psychotherapeutic interventions, more than 40% of patients with obsessive-compulsive disorder (OCD) do not respond to conventional treatment approaches. Transcranial direct current stimulation (tDCS) has been recently proposed as a therapeutic tool to alleviate treatment-resistant symptoms in patients with OCD. The aim of this review was to provide a comprehensive overview of the current state of the art and future clinical applications of tDCS in patients with OCD. A literature search conducted on the PubMed database following PRISMA guidelines and completed by a manual search yielded 12 results: eight case reports, three open-label studies (with 5, 8, and 42 participants), and one randomized trial with two active conditions (12 patients). There was no sham-controlled study. A total of 77 patients received active tDCS with a large diversity of electrode montages mainly targeting the dorsolateral prefrontal cortex, the orbitofrontal cortex or the (pre-) supplementary motor area. Despite methodological limitations and the heterogeneity of stimulation parameters, tDCS appears to be a promising tool to decrease obsessive-compulsive symptoms as well as comorbid depression and anxiety in patients with treatment-resistant OCD. Further sham-controlled studies are needed to confirm these preliminary results

Resting-state functional connectivity of the nucleus accumbens in auditory and visual hallucinations in schizophrenia

International audienceBoth auditory hallucinations (AH) and visual hallucinations may occur in schizophrenia. One of the main hypotheses underlying their occurrence involves the increased activity of the mesolimbic pathway, which links the ventral tegmental area (VTA) and the nucleus accumbens (NAcc). However, the precise contribution of the mesolimbic pathway in hallucinations across various sensory modalities has not yet been explored. We compared the resting-state functional connectivity (rs-FC) of the NAcc among 16 schizophrenia patients with pure AH, 15 with both visuoauditory hallucinations (VAH), and 14 without hallucinations (NoH). A between-group comparison was performed using random-effects ANCOVA (rs-FC of the bilateral NAcc as the dependent variable, groups as the between-subjects factor, age and Positive and Negative Syndrome Scale scores as covariates; q(false discovery rate [FDR]) < .05). Compared to the NoH group, the AH group exhibited significantly enhanced NAcc rs-FC with the left temporal superior gyrus, the cingulate gyri, and the VTA, whereas the VAH group, compared to the AH group, exhibited significantly enhanced NAcc rs-FC with the bilateral insula, putamen, parahippocampal gyri, and VTA. The strength in rs-FC between the NAcc and the VTA appeared to be positively associated with the presence of hallucinations, but the NAcc FC patterns changed with the complexity of these experiences (ie, 0, 1, or 2 sensory modalities), rather than with severity. This might support the aberrant salience hypothesis of schizophrenia. Moreover, these findings suggest that future clinical and neurobiological studies of hallucinations should evaluate not only the global severity of symptoms but also their sensorial features

Resistant depression : potentiation strategies

International audienceLithium is among the most classically recommended add-on therapeutic ă strategy for the management of depressive patients showing unsuccessful ă response to standard antidepressant medications. ă The effectiveness of the add-on strategy with lithium requires achieving ă plasma levels above 0.5 mEq/L. ă Mood-stabilizing antiepileptic drugs such as carbamazepine, valproate ă derivatives or lamotrigine have not demonstrated conclusive therapeutic ă effects for the management of depressive patients showing unsuccessful ă response to standard antidepressant medications. ă Thyroid hormones are considered among the currently recommended add-on ă therapeutic strategy for the management of depressive patients showing ă unsuccessful response to standard antidepressant medications. ă The effectiveness of the add-on strategy with thyroid hormones requires ă achieving plasma concentration of TSH close to the lower limits at the ă normal range (0.4 mUI/L) or even below it. Second-generation ă antipsychotics such as aripiprazole or quetiapine have consistently ă demonstrated significant therapeutic effects for the management of ă depressive patients showing unsuccessful response to standard ă antidepressant medications. ă Second-generation antipsychotics however require the careful monitoring ă of both cardiovascular and metabolic adverse effects