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

Deep Brain Stimulation in Treatment-Resistant Depression: A Systematic Review and Meta-Analysis on Efficacy and Safety

Objective: Deep brain stimulation (DBS) has shown promising outcomes as new therapeutic opportunities for patients with treatment-resistant depression (TRD) who do not respond adequately to several consecutive treatments. This study aims to systematically review and conduct a meta-analysis on the efficacy and safety of DBS for TRD.

Method: The literature was comprehensively reviewed using Medline, Google scholar, Cochrane library, Embase, and World Health Organization International Clinical Trials Registry Platform until January 2019. The studied outcomes included response, remission, recurrence, and adverse events (AEs) rates, and were reported as the rate ratio (RR) or pooled estimate with a 95% confidence interval (95% CI). Heterogeneity was measured by an I-square test and a sensitive analysis.

Results: A total of 17 studies involving 7 DBS targets were included. For efficacy, DBS treatment was statistically beneficial for TRD, and the response, remission, and recurrence rates were 56% (ranging from 43 to 69%), 35% (ranging from 27 to 44%), and 14% (ranging from 4 to 25%), respectively. However, only two randomized-controlled trials (RCTs) considered the invalidity of DBS (RR = 1.45, 95% CI = 0.50–4.21). For safety, the AEs rate was 67% (ranging from 54 to 80%). The AEs were common and moderate, but the problems related to suicide and suicidal ideation should not be underestimated.

Conclusion: These findings suggest that DBS for TRD is considered promising, which should be confirmed by well-designed and large sample studies. Future basic research and comprehensive clinical trials are needed to reach better understanding on the mechanisms of action and optimal targeted structure.

Brain stimulation treatments in bipolar disorder: A review of the current literature

OBJECTIVES

Brain stimulation techniques are non-pharmacologic strategies which offer additional therapeutic options for treatment-resistant depression (TRD). The purpose of this paper is to review the current literature regarding the use of brain stimulation in resistant bipolar disorder (BD), with particular reference to hypomanic/manic symptoms.

METHODS

Keywords pertaining to the brain simulation techniques used in the treatment of depression (either unipolar or bipolar) along with their role in regard to hypomanic/manic symptoms were used to conduct an electronic search of the literature. Pertinent findings were identified by the authors and reviewed.

RESULTS

Brain stimulation techniques represent a valid therapeutic option in TRD. They have been extensively studied in unipolar depression and, to a minor extent, in the depressive phase of BD, showing encouraging but often limited results. With exception of electroconvulsive therapy, the efficacy of brain stimulation in the treatment of manic symptoms of bipolar patients is still uncertain and needs to be fully evaluated.

CONCLUSIONS

Brain stimulation in BD is derived from its use in unipolar depression. However, there are many important differences between these two disorders and more studies with a systematic approach need to be conducted on larger samples of bipolar patients with treatment-resistant characteristics.

Brain stimulation therapies for psychiatric disorders: The first decade of the new millennium--A review

Three new brain stimulation therapies have emerged in the last decade for clinical use in psychiatric disorders. Combined with electroconvulsive therapy (ECT), these therapies offer much hope to patients with medication refractory depression, obsessive-compulsive disorder and auditory hallucinations of schizophrenia. In this article we briefly review the history, development and evidence for each of the four stimulation therapies and describe the current state-of-the-art. Neuromodulation is considered as a possible common mechanism mediating the effects of these therapies. Finally, empirical guidelines are suggested for the practicing psychiatrist for the optimal utilization of stimulation therapies. It is concluded that with increasing technological sophistication, research on optimal protocols and emergence of newer modalities of stimulation, the future holds much promise for neuromodulatory therapies in psychiatric disorders.

The use of ECT and MST in treating depression

Electroconvulsive therapy (ECT) has been used clinically since 1938. Its most common use is in the treatment of depression: first line treatment where rapid recovery is a priority, but more frequently as an effective treatment for patients who do not respond to pharmacological and psychological approaches. Whilst it is widely hailed as an effective treatment, concerns about its effect on cognition remain. The development of magnetic seizure therapy (MST) over the past decade has attempted to devise a therapy with comparable efficacy to ECT, but without the associated cognitive side effects. The rationale for this is that MST uses magnetic fields to induce seizures in the cortex, without electrical stimulation of brain structures involved with memory. MST has been used successfully in the treatment of depression, yet there is a dearth of literature in comparison with ECT. We present a systematic review of the literature on ECT (from 2009-2011) and MST (from 2001-2011).

Ten years of integrated care for mental disorders in the Netherlands

Background and problem statement

Integrated care for mental disorders aims to encompass forms of collaboration between different health care settings for the treatment of mental disorders. To this end, it requires integration at several levels, i.e. integration of psychiatry in medicine, of the psychiatric discourse in the medical discourse; of localization of mental health care and general health care facilities; and of reimbursement systems.

Description of policy practice

Steps have been taken in the last decade to meet these requirements, enabling psychiatry to move on towards integrated treatment of mental disorder as such, by development of a collaborative care model that includes structural psychiatric consultation that was found to be applicable and effective in several Dutch health care settings. This collaborative care model is a feasible and effective model for integrated care in several health care settings. The Bio Psycho Social System has been developed as a feasible instrument for assessment in integrated care as well.

Discussion

The discipline of psychiatry has moved from anti-psychiatry in the last century, towards an emancipated medical discipline. This enabled big advances towards integrated care for mental disorder, in collaboration with other medical disciplines, in the last decade.

Conclusion

Now is the time to further expand this concept of care towards other mental disorders, and towards integrated care for medical and mental co-morbidity. Integrated care for mental disorder should be readily available to the patient, according to his/her preference, taking somatic co-morbidity into account, and with a focus on rehabilitation of the patient in his or her social roles.

Traumatic brain injury, major depression, and diffusion tensor imaging: making connections

It is common for depression to develop after traumatic brain injury (TBI), yet despite poorer recovery, there is a lack in our understanding of whether post-TBI brain changes involved in depression are akin to those in people with depression without TBI. Modern neuroimaging has helped recognize degrees of diffuse axonal injury (DAI) as being related to extent of TBI, but its ability to predict long-term functioning is limited and has not been considered in the context of post-TBI depression. A more recent brain imaging technique (diffusion tensor imaging; DTI) can measure the integrity of white matter by measuring the directionality or anisotropy of water molecule diffusion along the axons of nerve fibers.

AIM

To review DTI results in the TBI and depression literatures to determine whether this can elucidate the etiology of the development of depression after TBI.

METHOD

We reviewed the TBI/DTI (40 articles) and depression/DTI literatures (17 articles). No articles were found that used DTI to investigate depression post-TBI, although there were some common brain regions identified between the TBI/DTI and depression/DTI studies, including frontotemporal, corpus callosum, and structures contained within the basal ganglia. Specifically, the internal capsule was commonly reported to have significantly reduced fractional anisotropy, which agrees with deep brain stimulation studies.

CONCLUSION

It is suggested that measuring the degree of DAI by utilizing DTI in those with or without depression post-TBI, will greatly enhance prediction of functional outcome.

Deep brain stimulation for obsessive-compulsive disorder and treatment-resistant depression: systematic review

Background

In spite of advances in psychotherapy and pharmacotherapy, there are still a significant number of patients with depression and obsessive-compulsive disorder that are not aided by either intervention. Although still in the experimental stage, deep brain stimulation (DBS) offers many advantages over other physically-invasive procedures as a treatment for these psychiatric disorders. The purpose of this study is to systematically review reports on clinical trials of DBS for obsessive-compulsive disorder (OCD) and treatment-resistant depression (TRD). Locations for stimulation, success rates and effects of the stimulation on brain metabolism are noted when available. The first observation of the effects of DBS on OCD and TRD came in the course of using DBS to treat movement disorders. Reports of changes in OCD and depression during such studies are reviewed with particular attention to electrode locations and associated adverse events; although these reports were adventitious observations rather than planned. Subsequent studies have been guided by more precise theories of structures involved in DBS and OICD. This study suggests stimulation sites and prognostic indicators for DBS. We also briefly review tractography, a relatively new procedure that holds great promise for the further development of DBS.

Methods

Articles were retrieved from MEDLINE via PubMed. Relevant references in retrieved articles were followed up. We included all articles reporting on studies of patients selected for having OCD or TRD. Adequacy of the selected studies was evaluated by the Jadad scale. Evaluation criteria included: number of patients, use of recognized psychiatric rating scales, and use of brain blood flow measurements. Success rates classified as "improved" or "recovered" were recorded. Studies of DBS for movement disorders were included if they reported coincidental relief of depression or reduction in OCD. Most of the studies involved small numbers of subjects so individual studies were reviewed.

Results

While the number of cases was small, these were extremely treatment-resistant patients. While not everyone responded, about half the patients did show dramatic improvement. Associated adverse events were generally trivial in younger psychiatric patients but often severe in older movement disorder patients. The procedures differed from study to study, and the numbers of patients was usually too small to do meaningful statistics or make valid inferences as to who will respond to treatment.

Conclusions

DBS is considered a promising technique for OCD and TRD. Outstanding questions about patient selection and electrode placement can probably be resolved by (a) larger studies, (b) genetic studies and (c) imaging studies (MRI, fMRI, PET, and tractography).