Left prefrontal transcranial magnetic stimulation (TMS) treatment of depression in bipolar affective disorder: a pilot study of acute safety and efficacy

Transcranial magnetic stimulation in the treatment of psychiatric disorders

Transcranial magnetic stimulation (TMS) is an emerging novel treatment modality for psychiatric disorders, particularly major depression. A device for delivery of TMS was approved by the US Food and Drug Administration for treatment of major depressive disorder in adults. TMS is being studied for a variety of psychiatric disorders, including obsessive-compulsive disorder, post-traumatic stress disorder, and auditory hallucinations in schizophrenia. In this article, we describe TMS and its neurobiologic basis, as well as the efficacy and safety data of TMS with regard to a range of psychiatric disorders.

A study of the effectiveness of high-frequency left prefrontal cortex transcranial magnetic stimulation in major depression in patients who have not responded to right-sided stimulation

The objective of this study was to explore the response rate to high-frequency left-sided repetitive transcranial magnetic stimulation (rTMS) in patients who had failed to respond to right-sided low-frequency stimulation, and to investigate whether there was differential efficacy between stimulation at 5 or 10 Hz. Data from two randomized controlled trials were pooled. In both studies a group of patients were randomized to receive either 5- or 10-Hz left prefrontal rTMS after failing to respond to right-sided stimulation. These patients received blinded 5- or 10-Hz stimulation (but without a sham control) for a period of up to 4 weeks and outcomes were compared. There was a small but significant overall response to left-sided rTMS but no difference in response between the 5- and 10-Hz treatment conditions. There appears to be a significant but modest likelihood of response to left-sided TMS in patients who fail right-sided stimulation, but there is no difference in efficacy between 5- and 10-Hz stimulation.

Opposite effects of high and low frequency rTMS on mood in depressed patients: relationship to baseline cerebral activity on PET

BACKGROUND

Optimal parameters of rTMS for antidepressant efficacy in general, or within patients, have not been adequately delineated.

METHODS

Using a double-blind, sham-controlled, cross-over design, 22 adult patients with treatment refractory major depression (n=9; bipolar disorder, depressed phase) were randomized to active rTMS (20-Hz or 1-Hz) or sham rTMS conditions and given 5 rTMS treatments per week for two weeks. Repetitive TMS was administered at 100% of motor threshold for 1600 pulses over the left prefrontal cortex using a figure-eight coil. Patients initially randomized to sham rTMS were then exposed to two weeks of active rTMS with each frequency under blinded conditions. Those who received active 20-Hz and 1-Hz rTMS were crossed over to the opposite frequency for two weeks. Improvement in Hamilton Depression ratings were assessed after each two-week treatment phase. PET imaging was used to evaluate the patient's baseline absolute regional cerebral activity (blood flow and metabolism) as potential predictor of clinical response.

RESULTS

Changes in depression severity on 1-Hz and 20-Hz rTMS were inversely correlated. PET scans with baseline hypoperfusion (but not hypometabolism) were associated with better improvement on 20-Hz rTMS as predicted.

LIMITATIONS

The magnitude of the clinical change with either frequency at 100% motor threshold was not robust, and larger studies with higher intensities of rTMS for longer durations of time should be explored.

CONCLUSIONS

High and low frequency rTMS exerts differential effects on depressed mood within individual subjects. The brain activity predictors and correlates of an optimal antidepressant response to rTMS remain to be better defined.

Augmentative repetitive navigated transcranial magnetic stimulation (rTMS) in drug-resistant bipolar depression

OBJECTIVES

The efficacy of transcranial magnetic stimulation (TMS) has been poorly investigated in bipolar depression. The present study aimed to assess the efficacy of low-frequency repetitive TMS (rTMS) of the right dorsolateral prefrontal cortex (DLPFC) combined with brain navigation in a sample of bipolar depressed subjects.

METHODS

Eleven subjects with bipolar I or bipolar II disorder and major depressive episode who did not respond to previous pharmacological treatment were treated with three weeks of open-label rTMS at 1 Hz, 110% of motor threshold, 300 stimuli/day.

RESULTS

All subjects completed the trial showing a statistically significant improvement on the 21-item Hamilton Depression Rating Scale (HAM-D), Montgomery-Asberg Depression Rating Scale, and Clinical Global Impression severity of illness scale (ANOVAs with repeated measures: F = 22.36, p < 0.0001; F = 12.66, p < 0.0001; and F = 10.41, p < 0.0001, respectively). In addition, stimulation response, defined as an endpoint HAM-D score reduction of > or =50% compared to baseline, was achieved by 6 out of 11 subjects, 4 of whom were considered remitters (HAM-D endpoint score < or = 8). Partial response (endpoint HAM-D score reduction between 25% and 50%) was achieved by 3/11 patients. No manic/hypomanic activation was detected during the treatment according to Young Mania Rating Scale scores (ANOVAs with repeated measures: F = 0.62, p = 0.61). Side effects were slight and were limited to the first days of treatment.

CONCLUSIONS

Augmentative low-frequency rTMS of the right DLPFC combined with brain navigation was effective and well tolerated in a small sample of drug-resistant bipolar depressive patients, even though the lack of a sham controlled group limits confidence in the results.

Antidepressant efficacy of high-frequency transcranial magnetic stimulation over the left dorsolateral prefrontal cortex in double-blind sham-controlled designs: a meta-analysis

BACKGROUND

For more than a decade high-frequency repetitive transcranial magnetic stimulation (rTMS) has been applied to the left dorsolateral prefrontal cortex (DLPFC) in search of an alternative treatment for depression. The aim of this study was to provide an update on its clinical efficacy by performing a meta-analysis involving double-blind sham-controlled studies.

METHOD

A literature search was conducted in the databases PubMed and Web of Science in the period between January 1980 and November 2007 with the search terms 'depression' and 'transcranial magnetic stimulation'. Thirty double-blind sham-controlled parallel studies with 1164 patients comparing the percentage change in depression scores from baseline to endpoint of active versus sham treatment were included. A random effects meta-analysis was performed to investigate the clinical efficacy of fast-frequency rTMS over the left DLPFC in depression.

RESULTS

The test for heterogeneity was not significant (QT=30.46, p=0.39). A significant overall weighted mean effect size, d=0.39 [95% confidence interval (CI) 0.25-0.54], for active treatment was observed (z=6.52, p<0.0001). Medication resistance and intensity of rTMS did not play a role in the effect size.

CONCLUSIONS

These findings show that high-frequency rTMS over the left DLPFC is superior to sham in the treatment of depression. The effect size is robust and comparable to at least a subset of commercially available antidepressant drug agents. Current limitations and future prospects are discussed.

The contemporary face of bipolar illness: complex diagnostic and therapeutic challenges

Manic depression, or bipolar disorder, is a multifaceted illness with an inevitably complex treatment. The current article summarizes the current status of our knowledge and practice concerning its diagnosis and treatment. While the prototypic clinical picture concerns the "classic" bipolar disorder, today mixed episodes with incomplete recovery and significant psychosocial impairment are more frequent. The clinical picture of these mixed episodes is variable, eludes contemporary classification systems, and possibly includes a constellation of mental syndromes currently classified elsewhere. Treatment includes the careful combination of lithium, antiepileptics, atypical antipsychotics, and antidepressants, but not all of the agents in these broad categories are effective for the treatment of bipolar disorder.

Treatment of bipolar depression: an update

This article attempts to summarize the current status of our knowledge and practice in the acute treatment and prophylaxis of bipolar depression. For prophylactic treatment, our knowledge about lithium firmly supports its usefulness against bipolar depression and its specific effectiveness for suicidal prevention. Valproic acid and carbamazepine could be effective, too, while lamotrigine which seems to be preferably effective against depression but not mania. The FDA has approved the olanzapine-fluoxetine combination and quetiapine monotherapy for the treatment of acute bipolar depression. The usefulness of antidepressants in bipolar depression is controversial both for acute and prophylactic treatment; guidelines suggest their cautious use and always in combination with an antimanic and mood stabilizer agent, because in some patients they may induce switching to mania or hypomania, mixed episodes and rapid cycling. Data on psychosocial intervention are restricted to the maintenance phase. Electroconvulsive therapy and transcranial magnetic stimulation are additional options for refractory patients. Bipolar depression seems to be a more difficult condition to treat than mania. Most patients need complex combination treatment although the published evidence on this type of treatment is limited.

Controversy: Repetitive transcranial magnetic stimulation or transcranial direct current stimulation shows efficacy in treating psychiatric diseases (depression, mania, schizophrenia, obsessive-complusive disorder, panic, posttraumatic stress disorder)

Brain imaging studies performed over the past 20 years have generated new knowledge about the specific brain regions involved in the brain diseases that have been classically labeled as psychiatric. These include the mood and anxiety disorders, and the schizophrenias. As a natural next step, clinical researchers have investigated whether the minimally invasive brain stimulation technologies (transcranial magnetic stimulation [TMS] or transcranial direct current stimulation [tDCS]) might potentially treat these disorders. In this review, we critically review the research studies that have examined TMS or tDCS as putative treatments for depression, mania, obsessive-complusive disorder, posttraumatic stress disorder, panic disorder, or schizophrenia. (Separate controversy articles deal with using TMS or tDCS to treat pain or tinnitus. We will not review here the large number of studies using TMS or tDCS as research probes to understand disease mechanisms of psychiatric disorders.) Although there is an extensive body of randomized controlled trials showing antidepressant effects of daily prefrontal repetitive TMS, the magnitude or durability of this effect remains controversial. US Food and Drug Administration approval of TMS for depression was recently granted. There is much less data in all other diseases, and therapeutic effects in other psychiatric conditions, if any, are still controversial. Several issues and problems extend across all psychiatric TMS studies, including the optimal method for a sham control, appropriate coil location, best device parameters (intensity, frequency, dosage, and dosing schedule) and refining what subjects should be doing during treatment (activating pathologic circuits or not). In general, TMS or tDCS as a treatment for most psychiatric disorders remains exciting but controversial, other than prefrontal TMS for depression.

Brain stimulation techniques for the treatment of depression and other psychiatric disorders

OBJECTIVE

The aim of this paper was to review the development of repetitive transcranial magnetic stimulation (rTMS), magnetic seizure therapy (MST), vagal nerve stimulation (VNS), deep brain stimulation (DBS) and other recent brain stimulation techniques for their potential use in the treatment of a range of psychiatric disorders.

CONCLUSIONS

A considerable number of studies have been conducted to investigate the efficacy of rTMS. Although there are considerable problems with this research base, globally the studies suggest that rTMS has antidepressant efficacy. However, more research is required to define the most effective way of applying this technique. There is a much smaller research base supporting the use of VNS and to date the research suggests that only a minority of patients benefit from this procedure. Considerably more research is required in the use of the other techniques which at this stage have been tested only to a very small degree. It is likely that one, and possibly a number, of the new brain stimulation techniques will become available clinically in the psychiatric armamentarium in the coming years. However, considerable research is still required to establish efficacy and define the appropriate place in clinical practice for these treatment approaches.

Antidepressant drugs modulate growth factors in cultured cells

BACKGROUND

Different classes of antidepressant drugs are used as a treatment for depression by activating the catecholinergic system. In addition, depression has been associated with decrease of growth factors, which causes insufficient axonal sprouting and reduced neuronal damage repair. In this study, antidepressant treatments are analyzed in a cell culture system, to study the modulation of growth factors.

RESULTS

We quantified the transcription of several growth factors in three cell lines after application of antidepressant drugs by real time polymerase chain reaction. Antidepressant drugs counteracted against phorbolester-induced deregulation of growth factors in PMA-differentiated neuronal SY5Y cells. We also found indications in a pilot experiment that magnetic stimulation could possibly modify BDNF in the cell culture system.

CONCLUSION

The antidepressant effects antidepressant drugs might be explained by selective modulation of growth factors, which subsequently affects neuronal plasticity.

Treatment-emergent mania in unipolar and bipolar depression: focus on repetitive transcranial magnetic stimulation

This review focused on the treatment-emergent mania/hypomania (TEM) associated with repetitive transcranial magnetic stimulation (rTMS) treatment of depression. English-language literature published from 1966-2006 and indexed in Medline was searched. Ten of 53 randomized controlled trials on rTMS treatment of depression specifically addressed TEM. The pooled TEM rate is 0.84% for the active treatment group and 0.73% for the sham group. The difference is not statistically significant. Along with case reports, a total of 13 cases of TEM associated with rTMS treatment of depression have been published. Most of these patients were diagnosed with bipolar disorder and the majority of patients experiencing TEM took medication concurrent with rTMS. The parameters of rTMS used in these cases were scattered over the spectrum of major parameters explored in previous studies. Most train durations and intervals were within the published safety guidelines of the field. Reducing the frequency of sessions from two per day to one per day might be associated with a lower likelihood of TEM recurrence. The severity of manic symptoms varied significantly, but all cases responded to treatment that included a decrease or discontinuation of antidepressant and/or rTMS treatment and/or use of anti-manic medication. Current data suggests that rTMS treatment carries a slight risk of TEM that is not statistically higher than that associated with sham treatment. More systematic studies are needed to better understand TEM associated with rTMS. Special precautions and measures should be adopted to prevent, monitor, and manage TEM in research and practice.

A review of the safety of repetitive transcranial magnetic stimulation as a clinical treatment for depression

There is growing interest worldwide in rTMS as a clinical treatment for depression. Apart from efficacy, its safety as a clinical treatment must be considered before its widespread use can be advocated. All published, sham-controlled rTMS depression trials were reviewed for reported side-effects and outcomes of formal neuropsychological testing. In addition, all reports of seizures occurring with rTMS were reviewed. Other safety concerns (effects on hearing; headache, pain, induced currents in electrical circuits, histotoxicity, electromagnetic field exposure, psychiatric complications, safety in pregnancy) are discussed. Common side-effects were of a minor nature, e.g. headache. There was a low incidence of accidental seizures and induced hypomania, both of which were associated with identified risk factors for which subjects should be screened. Long-term effects of repeated rTMS sessions are as yet unknown. When given within recommended guidelines, the overall safety profile of rTMS is good, and supports its further development as a clinical treatment.

Antidepressant effects of augmentative transcranial magnetic stimulation: randomised multicentre trial

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) has been proposed as a new treatment option for depression. Previous studies were performed with low sample sizes in single centres and reported heterogeneous results.

AIMS

To investigate the efficacy of rTMS as augmentative treatment in depression.

METHOD

In a randomised, double-blind, sham-controlled multicentre trial 127 patients with moderate to severe depressive episodes were randomly assigned to real or sham stimulation for 3 weeks in addition to simultaneously initiated antidepressant medication.

RESULTS

We found no difference in the responder rates of the real and the sham treatment groups (31% in each) or in the decrease of the scores on the depression rating scales.

CONCLUSIONS

The data do not support previous reports from smaller samples indicating an augmenting or accelerating antidepressant effect of rTMS. Further exploration of the possible efficacy of other stimulation protocols or within selected sub-populations of patients is necessary.

Treatment of bipolar disorder: a complex treatment for a multi-faceted disorder

BACKGROUND

Manic-depression or bipolar disorder (BD) is a multi-faceted illness with an inevitably complex treatment.

METHODS

This article summarizes the current status of our knowledge and practice of its treatment.

RESULTS

It is widely accepted that lithium is moderately useful during all phases of bipolar illness and it might possess a specific effectiveness on suicidal prevention. Both first and second generation antipsychotics are widely used and the FDA has approved olanzapine, risperidone, quetiapine, ziprasidone and aripiprazole for the treatment of acute mania. These could also be useful in the treatment of bipolar depression, but only limited data exists so far to support the use of quetiapine monotherapy or the olanzapine-fluoxetine combination. Some, but not all, anticonvulsants possess a broad spectrum of effectiveness, including mixed dysphoric and rapid-cycling forms. Lamotrigine may be effective in the treatment of depression but not mania. Antidepressant use is controversial. Guidelines suggest their cautious use in combination with an antimanic agent, because they are supposed to induce switching to mania or hypomania, mixed episodes and rapid cycling.

CONCLUSION

The first-line psychosocial intervention in BD is psychoeducation, followed by cognitive-behavioral therapy. Other treatment options include Electroconvulsive therapy and transcranial magnetic stimulation. There is a gap between the evidence base, which comes mostly from monotherapy trials, and clinical practice, where complex treatment regimens are the rule.

Efficacité de la stimulation magnétique transcrânienne (rTMS) dans le traitement de la dépression : revue de la littérature

INTRODUCTION

In 1985, Barker et al. showed that it was possible to stimulate both nerves and brain using external magnetic stimulation without significant pain. During the past 10 years, therapeutic effects of repeated Transcranial Magnetic Stimulation (rTMS) have been widely studied in psychiatry and its efficacy has been demonstrated in the treatment of major depressive disorders, particularly as an alternative to electroconvulsivotherapy (ECT). Facing the large range of studies, we found necessary to propose an up-to-date review in French of the methodological and therapeutic variations among them.

METHOD

Based on an exhaustive consultation of Medline data and the Avery-George-Holtzheimer Database of rTMS Depression-Studies, supplemented by a manual research, only works evaluating the therapeutic efficacy of rTMS on depressive symptoms were retained, excluding all studies exclusively investigating the stimulation parameters or the tolerance as well as case reports.

RESULTS

Out the 66 available reports we retained 30 studies. After a description of the main results of these 30 studies, several elements of the 66 will be discussed. Open studies demonstrated that short courses rTMS (5 to 10 sessions) produced a decrease in the mean Hamilton Depression Ratting Scale (HDRS) scores, although significant remission of depression in individuals was rare. Most authors had used high frequency rTMS applied to the left Dorso Lateral Prefrontal Cortex (left DLPFC). However, low frequency rTMS applied to the right DLPFC was also followed by significant reduction of HDRS scores. Parallel arm, double blind versus placebo studies are designed to clarify the therapeutic efficacy of rTMS therapy but conclude in contradicting results. Literature data globally confirms a greater efficacy of rTMS compared to placebo (37% responders in the active group vs 20% in the sham). This efficacy could in fact be even greater because the sham procedure is disputable in most studies. Indeed, positioning rTMS coil at 45 or 90 from the scalp may not represent an accurate sham procedure and the use of real sham coil is to be recommended. Only one study has suggested that associating rTMS and ECT could decrease the number of general anesthesia required. Therapeutic efficacy has been shown by either inhibiting the right DLPFC or by stimulating the left DLPFC, although some patients exhibit paradoxical responses. High frequency rTMS (>5 Hz) increases cortical excitability and metabolism, while low-frequency rTMS stimulation ( 1 Hz) has the opposite effect. Other parameters are: relevant: intensity (from 80 to 110% of motor threshold), total number of stimulations (from 120 to 2 000) and total number of rTMS sessions (from 5 to 20). As suggested in most recent studies, higher-intensity pulses, higher number of stimulation or longer treatment courses may be more effective. Greater responsiveness to rTMS may be predicted by several patients' factors, including the absence of psychosis, younger age and previous response to rTMS therapy.

DISCUSSION

Conclusions on these factors and others, such as the importance of anatomically accurate coil placement and the distance from the coil to the brain, await further investigation. Despite heterogeneity of these reports according to methodology and treatment parameters, the antidepressive properties of rTMS now appear obvious, opening interesting prospects, in particular in the treatment of pharmacoresistant major depressive patients and, we hope, administered as adjuvant therapy in non-resistant depression.

CONCLUSION

Thus, many questions remain unanswered concerning the optimal stimulation parameters, privileged indications and maintenance sessions. This justifies the development of structured evaluation trials on larger samples.

Induction of a mixed depressive episode during rTMS treatment in a patient with refractory major depression

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive experimental technique which has mostly been investigated in the treatment of mood disorders with possible efficacy in depression. Among its potential side effects, there have been some reports of rTMS-induced (hypo)mania in the literature but none for rTMS-induced mixed episodes. We report the case of a 39-year-old woman suffering from refractory chronic major depression who developed a depressive mixed episode associated with a mild serotonin syndrome during her second week of rTMS treatment. She was receiving a combination of antidepressants, the doses of which were kept unchanged during rTMS treatment. Mixed as well as manic episodes may be induced by transcranial magnetic stimulation, complications already observed with antidepressants and electroconvulsive therapy. Therefore, caution should be exercised among clinicians using this experimental procedure, particularly in the treatment of bipolar depressed patients.

Acute prefrontal cortex TMS in healthy volunteers: Effects on brain 11C-αMtrp trapping

High-frequency repetitive transcranial magnetic stimulation (rTMS) of the left dorsolateral prefrontal cortex (LDLPFC) is a technique with purported efficacy as a treatment for major depression. Here, we assessed in vivo, in healthy volunteers, the effect of acute rTMS of the LDLPFC, relative to the stimulation of the left occipital cortex (LOC), on brain regional serotonin synthesis capacity, using the [(11)C]-alpha-methyl-tryptophan ((11)C-alphaMtrp)/PET method. Ten subjects were studied twice, once following rTMS of the LDLPFC and once following rTMS of the LOC in a randomized counterbalanced order. Three blocks of 15 trains of 10 Hz rTMS were delivered 10 min apart. Behavioural and autonomic measures were recorded before and after each rTMS session. Comparisons of TMS-related changes in regional normalized brain uptake and trapping of (11)C-alphaMtrp (K*) values were carried out using SPM99. Statistically significant regional differences were identified on the basis of an extent threshold of 50 voxels, with a peak threshold of p=0.005 uncorrected. Behavioural and autonomic measures were unaffected by rTMS. Relative to LOC stimulation, LDLPFC rTMS was associated with marked changes in normalized K* in limbic areas, with significantly lower values in the left parahippocampal gyrus (BA 28) and the right insula (BA 13), and higher values in the right cingulate gyrus (BA 31) and cuneus (BA 18). These findings indicate that acute rTMS of the LDLPFC in healthy volunteers modulates aspects of tryptophan/5-HT metabolism in limbic areas. Such adaptive changes may contribute to the mechanism of action of prefrontal rTMS in major depression.

"Getting physical": the management of neuropsychiatric disorders using novel physical treatments

OBJECTIVE

To summarize and review the utility of physical interventions in the treatment of psychiatric disorders.

METHODS

A systematic review of the literature pertaining to novel physical interventions, namely, transcranial magnetic stimulation, deep brain stimulation, vagus nerve stimulation, and neurosurgery, was conducted using MEDLINE, EMBASE, and PSYCHLIT. Bibliographies of papers were scrutinized for further relevant references along with literature known to the authors.

RESULTS

Currently available physical interventions worldwide are reviewed with respect to efficacy, applications, and putative indications. Physical interventions have experienced a resurgence of interest for both the investigation of brain function and the treatment of neuropsychiatric disorders. The widespread availability of neuroimaging technology has advanced our understanding of brain function and allowed closer examination of the effects of physical treatments. Clinically, transcranial magnetic stimulation seems likely to have a role in the management of depression, and its use in other neuropsychiatric disorders appears promising. Following on from its success in the management of intractable epilepsy, vagus nerve stimulation is undergoing evaluation in the treatment of depression with some success in refractory cases. Deep brain stimulation has improved mood in patients with Parkinson's disease and may also relieve symptoms of obsessive-compulsive disorder. Neurosurgery has re-invented itself by way of increased technical sophistication, and although further assessment of its efficacy and clinical utility is still needed, its widespread practice reflects its increasing acceptance as a viable treatment of last resort.

CONCLUSION

It is clear that physical treatments are here to stay and "getting physical" offers a useful addition to the neuropsychiatrist's therapeutic armamentarium. However, like all new treatments these interventions need to remain under rigorous scientific scrutiny to determine accurately their immediate and long-term effects.

Transcranial magnetic stimulation for depression

OBJECTIVE

To review the accumulated literature on the efficacy, safety and predictors of response for repetitive transcranial magnetic stimulation (rTMS) in the treatment of depression.

METHODS

A descriptive review of the more than 25 published sham-controlled rTMS studies in depression was undertaken, focusing on reported meta-analyses as well as individual trial reports. Potential determinants of efficacy were examined, including the form of shams employed, stimulation parameters and clinical features.

RESULTS

There is now clear evidence for the statistical superiority of left-prefrontal high frequency rTMS compared with sham therapy. However, the clinical benefits are marginal in the majority of reports. There is also still considerable uncertainty concerning the optimal stimulation parameters. Those clinical features which appear to be associated with greater response include younger age, lack of refractoriness to antidepressants and no psychotic features.

CONCLUSIONS

Current studies confirm statistical efficacy, but insubstantive clinical benefit. Large multicentre studies currently underway should clarify if rTMS should be approved by regulatory agencies for widespread clinical availability. Furthermore, there is a need to clarify the preferred parameters for administering this treatment.

Safety and efficacy of repetitive transcranial magnetic stimulation in the treatment of depression: a critical appraisal of the last 10 years

Depression is a common and debilitating illness, for which alternative treatments are urgently needed. Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive and relatively painless experimental technique of altering brain physiology. The authors critically review the evidence for the efficacy, safety and tolerability of rTMS in the treatment of depression based on published data over the last decade. They also discuss studies which have examined relevant clinical, demographic, methodological, and technical parameters that might be implicated in optimizing the antidepressant efficacy of this technique. rTMS depression trials conducted through early 2006 are included in this review, which focuses mainly on the results of published sham-controlled studies, literature reviews and meta-analyses. Trials published so far have been characterized by the use of a great variety of stimulation parameters, study designs, questionable sham controls, small sample sizes and heterogeneously depressed populations, all of which have made comparisons between studies difficult. Meta-analyses of 2-week rTMS sham-controlled studies support, for the most part, the antidepressant effects of rTMS which are statistically superior to sham. However, the degree of clinical improvement remains small, although greater efficacy has been shown with longer treatment courses and predictors of response to rTMS are progressively being identified. rTMS is a promising antidepressant treatment with overall minor adverse effects. Because the clinical efficacy of rTMS as an antidepressant remains questionable, further systematic, large-scale multicenter studies comparing rTMS to a sham and/or to an antidepressant medication along with more stringent stimulation parameters are warranted in order to identify patient populations most likely to benefit and treatment parameters most likely to optimize its antidepressant efficacy.

Newer treatment studies for bipolar depression

OBJECTIVE

Depressive symptoms of bipolar disorder have more negative impact on a patient's life than manic symptoms. This review focused on the emerging efficacy data for treatments in bipolar depression.

METHODS

English-language literature cited in Medline was searched with terms bipolar depression, clinical trial, and trial. Randomized, placebo-controlled trials of newer studies with older agents and all studies with newer or novel agents were prioritized. Open-label studies of novel agents presented at major scientific meetings were also included.

RESULTS

Olanzapine, olanzapine-fluoxetine combination (OFC), and quetiapine were superior to placebo in the acute treatment of bipolar depression. Lamotrigine only significantly reduced core symptoms of depression compared with placebo. Pramipexole, a dopamine D2/D3 receptor agonist and omega-3 fatty acids, a polyunsaturated fatty acid, augmentation to mood stabilizer (MS) had superiority to placebo in reducing depressive symptoms. Topiramate augmentation of an MS was equally as effective as Bupropion-SR. Patients treated with an MS responded well to the addition of agomelatine, a melatonin receptor agonist with 5-HT2C antagonist properties. However, inositol and repetitive transcranial magnetic stimulation did not separate from placebo. Lamotrigine and olanzapine, and to a lesser extent, divalproex, are superior to placebo in preventing depressive relapses. All agents were relatively well tolerated.

CONCLUSIONS

Olanzapine, OFC, and quetiapine are effective in the acute treatment of bipolar depression. Compared with lithium and divalproex, lamotrigine is more effective in preventing bipolar depression. Larger controlled studies of the other agents in the acute and maintenance treatment of bipolar depression are warranted.

Recent developments and current controversies in depression

In this review of the last 5 years' developments in research into depression we focus on recent advances and current controversies. We cover epidemiology and basic science as well as the treatment of depression in adults in all its forms. Depression in , as well as in has been covered in recent Seminars in The Lancet. Depression in adulthood remains a very common and under-treated condition, resulting in a high degree of disability. Increasingly detailed knowledge about impairment of information processing in depression is being supplemented by quantitative studies of the brain processes underlying these impairments. Most patients improve with present treatments. The mechanisms of action of antidepressants are not fully understood; the hypothesis that reversing hippocampal cell loss in depression may be their active principle is a fascinating new development. Moral panic about the claim that antidepressant serotonin reuptake inhibitors cause patients to commit suicide and become addicted to their medication may have disconcerted the public and members of the medical profession. We will try to describe the considerable effort that has gone into collecting evidence to enlighten this debate.

Safety of rTMS to non-motor cortical areas in healthy participants and patients

OBJECTIVE

rTMS is increasingly being used for stimulation to non-motor areas, but available safety guidelines are derived from experience with motor cortex rTMS. We reviewed the literature and our own data to assess the safety of rTMS to non-motor areas.

METHODS

We reviewed for adverse effects all articles published from January 1998 to December 2003 that applied rTMS to non-motor areas, and analyzed data from our own studies from January 1997 to December 2003.

RESULTS

Adverse effects were infrequent and generally mild. Headache was the most common, occurring in 23% of the subjects and more frequent with frontal rTMS. More serious adverse effects were rare and consisted of two seizures and four instances of psychotic symptoms induced by rTMS to the dorsolateral prefrontal cortex in patients with depression.

CONCLUSIONS

Overall, as currently applied rTMS to non-motor areas appears to be safe with few, generally mild adverse effects. In future studies, we recommend systematic reporting of adverse effects and careful documentation of machine type, coils used, and actual intensity as a function of maximum stimulator output. Phosphene threshold might be used to index stimulation intensity when rTMS is applied to the visual cortex, and research should be directed to identifying other indexes of intensity for TMS to other non-motor areas.

SIGNIFICANCE

rTMS under the present guidelines is safe, with minimal adverse effects, when applied to non-motor areas.

A review of the efficacy of transcranial magnetic stimulation (TMS) treatment for depression, and current and future strategies to optimize efficacy

BACKGROUND

There is a growing interest in extending the use of repetitive transcranial magnetic stimulation (rTMS) beyond research centres to the widespread clinical treatment of depression. Thus it is timely to critically review the evidence for the efficacy of rTMS as an antidepressant treatment. Factors relevant to the efficacy of rTMS are discussed along with the implications of these for the further optimization of rTMS.

METHOD

Clinical trials of the efficacy of rTMS in depressed subjects are summarized and reviewed, focusing mainly on sham-controlled studies and meta-analyses published to date.

RESULTS

There is a fairly consistent statistical evidence for the superiority of rTMS over a sham control, though the degree of clinical improvement is not large. However, this data is derived mainly from two-week comparisons of rTMS versus sham, and evidence suggests greater efficacy with longer treatment courses. Studies so far have also varied greatly in approaches to rTMS stimulation (with respect to stimulation site, stimulus parameters etc) with little empirical evidence to inform on the relative merits of these approaches.

LIMITATIONS

Only studies published in English were reviewed. Many of the studies in the literature had small sample sizes and different methodologies, making comparisons between studies difficult.

CONCLUSIONS

Current published studies and meta-analyses have evaluated the efficacy of rTMS as given in treatment paradigms that are almost certainly suboptimal (e.g of two weeks' duration). While the data nevertheless supports positive outcomes for rTMS, there is much scope for the further refinement and development of rTMS as an antidepressant treatment. Ongoing research is critical for optimizing the efficacy of rTMS.

Transcranial magnetic stimulation as a therapeutic tool in psychiatry

Transcranial magnetic stimulation (TMS) is a patient-friendly stimulation technique of the brain with interesting perspectives. In clinical psychiatry, limited data are available on activity in psychosis and anxiety, but much research has been done in depression. Major concerns on published papers are the inconsistency of used parameter settings, the restraint numbers of patients in randomised trials, the lack of real sham controlled studies and the quasi inexistent reproducibility of results. The most stringent meta-analysis of TMS in affective disorders found a modest, statistically significant antidepressant effect after 2 weeks of daily treatment of high frequency repetitive left dorsolateral prefrontal cortex stimulation. Although most results are rather weak and not convincing enough to promote TMS as evidence-based antidepressive therapy, they show a measurable action that should not be ignored. Preclinical and clinical effects were observed analysing heterogeneous data, and results comparing TMS to electroconvulsive therapy (ECT) in affective disorders are encouraging. Efforts should continue with emphasis on increasing homogeneity and reproducibility in data. Further refinement of stimulation parameters should be established, so that new and large double-blind, long-term, sham-controlled trials can bring us to better understanding and standardising TMS procedure, finally leading to definitive conclusions about its efficacy in psychiatry.

Treatment of bipolar depression

This article discusses current practices in the treatment of bipolar depression. In the absence of more definitive research, the treatment of bipolar depression is guided by clinical experience and expert opinion, and sometimes by marketing and popular trends, as much as it is by hard data. Considering the limitations of current knowledge is an essential component of the scientific practice of psychiatry.

Repetitive transcranial magnetic stimulation for treating medication-resistant depression in Taiwan: a preliminary study

BACKGROUND

We conducted an open trial to evaluate the efficacy of repetitive transcranial magnetic stimulation (rTMS) in medication-resistant depression. This is the first study in Taiwan of rTMS for the treatment of depression.

METHODS

A 2-week regimen of rTMS (100% of motor threshold, 5 Hz, 8 sec, 40 trains/20 min/day, 10 weekdays) applied to the left dorsolateral prefrontal cortex was administered to 11 patients with medication-resistant depression.

RESULTS

Ten subjects completed 2 weeks' treatment with rTMS. Scores on the 21-item Hamilton Depression Rating Scale (HAM-D21) and Beck Depression Inventory decreased by 48% and 28%, respectively. Five patients were clinical responders (> or = 50% reduction in HAM-D21 score): 2 of these were in complete remission (HAM-D21 score < or = 7). Five patients were less responsive: 2 of these were partial responders (20-49% reduction in HAM-D21 score), whereas 3 did not improve. Younger versus older age was identified as a potential predictor of response to rTMS used as add-on therapy.

CONCLUSION

Our preliminary results indicate that rTMS can improve mood in patients with medication-resistant depression, and can also potentially replace electroconvulsive therapy for certain types of medication-resistant depression. Future double-blind, placebo-controlled trials of rTMS are warranted.

Recent developments in the treatment of bipolar disorders

Recently, many new therapeutic options have become available for the treatment of bipolar disorder. Most of these options are agents originally developed to treat other conditions, such as anticonvulsants and antipsychotics. Some older agents have also been rediscovered or reformulated. New drug combinations and treatment strategies have enabled a more comprehensive treatment of the spectrum of bipolar symptoms, as well as bipolar disorder complicated by a range of comorbidities, to be targeted. A growing range of novel therapeutic options for the treatment of bipolar disorder is under investigation. This paper summarises some of the data regarding these potential therapeutic options.

Can left prefrontal rTMS be used as a maintenance treatment for bipolar depression?

Numerous studies have examined the acute antidepressant effects of prefrontal transcranial magnetic stimulation (TMS). However, there is little information on whether TMS can be used as a maintenance treatment to maintain normal mood once subjects have responded. We describe seven adults with bipolar depression who responded acutely to TMS and were then treated with TMS weekly for up to 1 year. TMS was carried out over the left prefrontal cortex at 110% motor threshold, 5 Hz for 8 s for 40 trains. Three subjects completed 1 full year of weekly TMS with an average Hamilton Rating Scale for Depression of 13 (sd = 5.9) over the year. These data suggest but do not prove that TMS might eventually be used as an adjunctive maintenance treatment for at least some patients with bipolar depression. Much work remains.

Rapid cycling bipolar disorder: historical overview and focus on emerging treatments

OBJECTIVE

Rapid cycling bipolar disorder presents a significant challenge with respect to treatment. The cyclical nature of bipolar disorder has been well recognised for over a century, and following Dunner and Fieve's landmark paper in 1974, investigators have increasingly turned their attention to issues such as the definition of rapid cycling, demographic characterisation, treatment response and pharmacologic intervention.

METHODS

A literature search using Medline was performed, and selected articles which consider important developments in the definition, demographics and course of rapid cycling are reviewed. In addition, a systematic review of the literature published during the past 5 years (1999-2004) relating to treatment was conducted.

RESULTS

Relevant articles are reviewed.

CONCLUSIONS

This review highlights the important developments in our understanding of rapid cycling bipolar disorder, and focuses particularly on the recent literature regarding treatment.

Feelings and emotions: roles for electrophysiological markers

Asymmetrical electroencephalogram (EEG) alpha activity over anterior regions of the scalp predicts a variety of outcome measures of interest to emotion researchers. This vast and diverse literature is examined from three different viewpoints. First, the organization of this vast literature is contrasted from theoretical and statistical perspectives, and the advantages and disadvantages of each perspective are considered. Second, the correlates of EEG asymmetry are sometimes treated as criterion (dependent) measures and at other times treated as predictor (independent) measures. Differences in the interpretation of each are surveyed, and the need for attention to whether EEG asymmetry is a simple correlate, mediator, or moderator of the associated affective measures is noted. Finally, the studies of EEG asymmetry and emotion that adopt a psychological perspective are contrasted with those that adopt a neurophysiological perspective, and the import of each for theory, experimental design, and analytic strategy is discussed.

Acute left prefrontal transcranial magnetic stimulation in depressed patients is associated with immediately increased activity in prefrontal cortical as well as subcortical regions

BACKGROUND

Focal prefrontal cortex repetitive transcranial magnetic stimulation (rTMS) was originally investigated as a potential antidepressant under the assumption that in depressed patients, prefrontal cortex stimulation would produce changes in connected limbic regions involved in mood regulation.

METHODS

Fourteen adult patients with depression were scanned in a 1.5-T scanner using interleaved rTMS (1 Hz) applied on the left prefrontal cortex over 7.35 min. Images were analyzed with Statistical Parametric Mapping 2b and principal component analysis.

RESULTS

Over the left prefrontal cortex, 1-Hz TMS was associated with increased activity at the site of stimulation as well as in connected limbic regions: bilateral middle prefrontal cortex, right orbital frontal cortex, left hippocampus, mediodorsal nucleus of the thalamus, bilateral putamen, pulvinar, and insula (t = 3.85, p <.001). Significant deactivation was found in the right ventromedial frontal cortex.

CONCLUSIONS

In depressed patients, 1-Hz TMS at 100% motor threshold over the left prefrontal cortex induces activation underneath the coil, activates frontal-subcortical neuronal circuits, and decreases activity in the right ventromedial cortex. Further work is needed to understand whether these immediate changes vary as a function of TMS use parameters (intensity, frequency, location) and whether they relate to neurobiologic effects and antidepressant mechanisms of TMS.

Current status of the utilization of antiepileptic treatments in mood, anxiety and aggression: drugs and devices

Interventions that have been utilized to control seizures in people with epilepsy have been employed by the psychiatric community to treat a variety of disorders. The purpose of this review will be to give an overview of the most prominent uses of antiepileptic drugs (AEDs) and devices like the Vagus Nerve Stimulator (VNS) and Transcranial Magnetic Stimulation (TMS) in the treatment of psychiatric disease states. By far, the most prevalent use of these interventions is in the treatment of mood disorders. AEDs have become a mainstay in the effective treatment of Bipolar Affective Disorder (BAD). The U.S. Food and Drug Administration has approved the use of valproic acid for acute mania, and lamotrigine for BAD maintenance therapy. AEDs are also effectively employed in the treatment of anxiety and aggressive disorders. Finally, VNS and TMS are emerging as possibly useful tools in the treatment of more refractory depressive illness.

Mechanisms and the current state of transcranial magnetic stimulation

Transcranial magnetic stimulation (TMS) is unique among the current brain stimulation techniques because it is relatively non-invasive. TMS markedly differs from vagus nerve stimulation, deep brain stimulation and magnetic seizure therapy, all of which require either an implanted prosthesis or general anesthesia, or both. Since its rebirth in its modern form in 1985, TMS has already shown potential usefulness in at least three important domains-as a basic neuroscience research instrument, as a potential clinical diagnostic tool, and as a therapy for several different neuropsychiatric conditions. The TMS scientific literature has now expanded beyond what a single summary article can adequately cover. This review highlights several new developments in combining TMS with functional brain imaging, using TMS as a psychiatric therapy, potentially using TMS to enhance performance, and finally recent advances in the core technology of TMS. TMS' ability to non-invasively and focally stimulate the brain of an awake human is proving to be a most important development for neuroscience in general, and neuropsychiatry in particular.