Neurostimulation therapies in depression: a review of new modalities.

OBJECTIVE: In response to an increased understanding of the neurobiology of severe psychiatric disorders, new therapeutic modalities are entering clinical practice that involve the direct stimulation of the brain. METHOD: We provide a review of published literature regarding the clinical use of vagus nerve stimulation (VNS) therapy, transcranial magnetic stimulation (TMS) and deep brain stimulation (DBS) in psychiatric disorders, with an emphasis on treatment-resistant depression (TRD). RESULTS: Vagus nerve stimulation is approved for use in both the EU and US for TRD. TMS has been approved for TRD in Canada, Australia, New Zealand, the European Union and Israel, but not yet in the United States. DBS remains in the early stages of investigation. CONCLUSION: While additional studies are clearly warranted, treatments that directly stimulate the brain appear to hold great therapeutic promise for severe psychiatric disorders.

The effects of vagus nerve stimulation on cognitive performance in patients with treatment-resistant depression.

BACKGROUND: Chronic vagus nerve stimulation (VNS) is effective in the management of treatment-resistant epilepsy. Open-trial evidence suggests that VNS has clinically significant antidepressant effects in some individuals who experience treatment-resistant major depressive episodes. However, limited information regarding the effects of VNS on neurocognitive performance exists. OBJECTIVE: The primary aim of this study was to determine whether VNS leads to neurocognitive deterioration. METHOD: A neuropsychological battery was administered to 27 patients with treatment-resistant depression before and after 10 weeks of VNS. Thirteen neurocognitive tests sampled the domains of motor speed, psychomotor function, language, attention, memory, and executive function. RESULTS: No evidence of deterioration in any neurocognitive measure was detected. Relative to baseline, improvement in motor speed (finger tapping), psychomotor function (digit-symbol test), language (verbal fluency), and executive functions (logical reasoning, working memory, response inhibition, or impulsiveness) was found. For some measures, improved neurocognitive performance correlated with the extent of reduction in depressive symptoms, but VNS output current was not related to changes in cognitive performance. CONCLUSIONS: Vagus nerve stimulation in treatment-resistant depression may result in enhanced neurocognitive function, primarily among patients who show clinical improvement. Controlled investigation is needed to rule out the contribution of practice effects.

Omega 3 fatty acids in bipolar disorder: a preliminary double-blind, placebo-controlled trial.

BACKGROUND: Omega3 fatty acids may inhibit neuronal signal transduction pathways in a manner similar to that of lithium carbonate and valproate, 2 effective treatments for bipolar disorder. The present study was performed to examine whether omega3 fatty acids also exhibit mood-stabilizing properties in bipolar disorder. METHODS: A 4-month, double-blind, placebo-controlled study, comparing omega3 fatty acids (9.6 g/d) vs placebo (olive oil), in addition to usual treatment, in 30 patients with bipolar disorder. RESULTS: A Kaplan-Meier survival analysis of the cohort found that the omega3 fatty acid patient group had a significantly longer period of remission than the placebo group (P = .002; Mantel-Cox). In addition, for nearly every other outcome measure, the omega3 fatty acid group performed better than the placebo group. CONCLUSION: Omega3 fatty acids were well tolerated and improved the short-term course of illness in this preliminary study of patients with bipolar disorder.