Efficacy Of rTMS In Depression Research Articles

Reprint of ‘‘Using neuroimaging to individualize TMS treatment for depression: Toward a new paradigm for imaging-guided intervention’’

The standard clinical technique for using repetitive transcranial magnetic stimulation (rTMS) for major depressive disorder (MDD) is associated with limited efficacy to date. Such limited efficacy may be due to reliance on scalp-based targeting rather than state-of-the-science methods which incorporate fMRI-guided neuronavigation based on a specific model of neurocircuit dysfunction. In this review, we examine such a specific model drawn from regulatory focus theory, which postulates two brain/behavior systems, the promotion and prevention systems, underlying goal pursuit. Individual differences in these systems have been shown to predict vulnerability to MDD as well as to comorbid generalized anxiety disorder (GAD). Activation of an individual's promotion or prevention goals via priming leads to motivational and affective responses modulated by the individual's appraisal of their progress in attaining the goal. In addition, priming promotion vs. prevention goals induces discriminable patterns of brain activation that are sensitive to the effects of depression and anxiety: MDD is associated with promotion system failure, anhedonic/dysphoric symptoms, and hypoactivation in specific regions in left prefrontal cortex, whereas GAD is associated with prevention system failure, hypervigilant/agitated symptoms, and hyperactivation in right prefrontal cortex (PFC). These left and right PFC locations can be directly targeted in an individualized manner for TMS. Additionally, this individually targeted rTMS can be integrated with cognitive interventions designed to activate the neural circuitry associated with promotion vs. prevention, thus allowing the neuroplasticity induced by the rTMS to benefit the systems likely to be involved in remediating depression. Targeted engagement of cortical systems involved in emotion regulation using individualized fMRI guidance may help increase the efficacy of rTMS in depression.

Using neuroimaging to individualize TMS treatment for depression: Toward a new paradigm for imaging-guided intervention

The standard clinical technique for using repetitive transcranial magnetic stimulation (rTMS) for major depressive disorder (MDD) is associated with limited efficacy to date. Such limited efficacy may be due to reliance on scalp-based targeting rather than state-of-the-science methods which incorporate fMRI-guided neuronavigation based on a specific model of neurocircuit dysfunction. In this review, we examine such a specific model drawn from regulatory focus theory, which postulates two brain/behavior systems, the promotion and prevention systems, underlying goal pursuit. Individual differences in these systems have been shown to predict vulnerability to MDD as well as to comorbid generalized anxiety disorder (GAD). Activation of an individual's promotion or prevention goals via priming leads to motivational and affective responses modulated by the individual's appraisal of their progress in attaining the goal. In addition, priming promotion vs. prevention goals induces discriminable patterns of brain activation that are sensitive to the effects of depression and anxiety: MDD is associated with promotion system failure, anhedonic/dysphoric symptoms, and hypoactivation in specific regions in left prefrontal cortex, whereas GAD is associated with prevention system failure, hypervigilant/agitated symptoms, and hyperactivation in right prefrontal cortex (PFC). These left and right PFC locations can be directly targeted in an individualized manner for TMS. Additionally, this individually targeted rTMS can be integrated with cognitive interventions designed to activate the neural circuitry associated with promotion vs. prevention, thus allowing the neuroplasticity induced by the rTMS to benefit the systems likely to be involved in remediating depression. Targeted engagement of cortical systems involved in emotion regulation using individualized fMRI guidance may help increase the efficacy of rTMS in depression.

Use of Repetitive Transcranial Magnetic Stimulation for Treatment in Psychiatry

The potential of noninvasive neurostimulation by repetitive transcranial magnetic stimulation (rTMS) for improving psychiatric disorders has been studied increasingly over the past two decades. This is especially the case for major depression and for auditory-verbal hallucinations in schizophrenia. The present review briefly describes the background of this novel treatment modality and summarizes evidence from clinical trials into the efficacy of rTMS for depression and hallucinations. Evidence for efficacy in depression is stronger than for hallucinations, although a number of studies have reported clinically relevant improvements for hallucinations too. Different stimulation parameters (frequency, duration, location of stimulation) are discussed. There is a paucity of research into other psychiatric disorders, but initial evidence suggests that rTMS may also hold promise for the treatment of negative symptoms in schizophrenia, obsessive compulsive disorder and post-traumatic stress disorder. It can be concluded that rTMS induces alterations in neural networks relevant for psychiatric disorders and that more research is needed to elucidate efficacy and underlying mechanisms of action.

Efficacité et tolérance de la stimulation magnétique transcrânienne (SMTr) dans le traitement des dépressions chez le sujet âgé : revue de la littérature

During the past 15 years, therapeutic effects of repetitive Transcranial Magnetic Stimulation (rTMS) have been studied in psychiatric diseases, particularly in the treatment of depressive disorders. There are more and more data suggesting its efficacy in the treatment of depression in older patients. Thus, the authors found it useful to conduct an up-to-date review of studies that examined the efficacy and safety of rTMS to treat depressive disorders in the aged. After an exhaustive consultation of databases (Medline/PubMed and the Avery-George-Holtzheimer Database of rTMS Depression Studies), supplemented by a manual research, the authors retained studies evaluating the therapeutic efficacy of rTMS on depressive disorders in the aged. Fifteen studies were retained. Four open studies using high frequency rTMS, applied to the left dorsolateral prefrontal cortex (DLPFC), demonstrated a decrease in the mean Hamilton Depression Rating Scale (HDRS) scores; however, only a quarter of the aged patients studied experienced a significant remission of depression. Five parallel arm double-blind versus placebo studies concluded in contradicting results: two studies confirmed a significantly greater efficacy of rTMS compared to placebo, whereas three studies did not; but the sham procedure (positioning coil at 90 degrees from the scalp) was disputable in most studies. One study concluded in therapeutic efficacy by inhibiting the right DLPFC. Three controlled parallel arm studies compared rTMS and electroconvulsive-therapy (ECT); one study concluded in greater efficacy of ECT at end of treatment, but the number of ECT treatments depended on the patients' response, whereas a 15-day course of rTMS was systematically administered; additionally HDRS scores were similar in two groups of patients (rTMS and ECT) at 6 months. Lastly, three studies focused on aged patients with cerebrovascular disease. They showed the efficacy of rTMS, although older age and smaller frontal gray mater volumes were associated with a poorer response to rTMS. Thus, although some studies concluded contradicting results, literature data globally sustain an efficacy of rTMS for depression in the elderly. Several parameters might be associated with greater antidepressant efficacy (higher intensity pulses of rTMS of the left DLPFC; higher number of stimulations or higher number of rTMS sessions). Poorer responsiveness to rTMS may be related to several patients' factors including older age and smaller frontal gray matter volumes; lesions of the white matter pathways connecting the left DLPFC and the left anterior cingulate cortex might explain a poor response to rTMS. Literature data globally confirm that rTMS is safe and does not produce cognitive deficits, even among highly vulnerable patients with clinical evidence of cerebrovascular disease. Many questions remain concerning the optimal stimulation parameters, administration protocol, and privileged indications. Thus, the next rTMS studies should be carefully designed to clarify these questions.