Brain stimulation for treatment-resistant depression

Depression is one of the main public health problems in the world, having a high prevalence and being considered the main cause of disability. An important portion of patients does not respond to treatment with the initial trial of conventional antidepressants in the current depressive episode of moderate to severe intensity, which characterizes treatment-resistant depression. In this context, non-invasive neuromodulation procedures use an electric current or magnetic field to modulate the central nervous system, and they represent a new option for patients with treatment-resistant depression.

A Clinical Case Series of Acute and Maintenance Home Administered Transcranial Direct Current Stimulation in Treatment-Resistant Depression

OBJECTIVES

Transcranial direct current stimulation (tDCS) is a noninvasive neurostimulation technique being translated clinically for the treatment of depression. There is limited research documenting the longer-term effectiveness and safety of tDCS treatment. This case series is the first report of remotely supervised, home-administered tDCS (HA-tDCS) for depression in a clinical setting.

METHODS

We report clinical, cognitive, and safety outcomes from 16 depressed patients who received acute and/or maintenance HA-tDCS. We retrospectively examined clinical data from up to 2.5 years of treatment. Descriptive statistics are reported to document patient outcomes.

RESULTS

Twelve patients received acute treatment for a current depressive episode and 4 commenced tDCS maintenance therapy after responding to ECT or repetitive transcranial magnetic stimulation (rTMS). The cohort was highly treatment-resistant wherein 15 of 16 patients failed 3 trials or more of antidepressant medication in the current episode, and 6 patients failed to gain significant benefit from prior ECT or rTMS. Five of 12 patients responded to acute tDCS within 6 weeks, and 9 patients who received tDCS for more than 12 weeks maintained improvements over several months. Cognitive tests showed no evidence of impairments in cognitive outcomes after up to 2 years of treatment. Two patients were withdrawn from treatment because of blurred vision or exacerbation of tinnitus. Transcranial direct current stimulation was otherwise safe and well tolerated.

CONCLUSIONS

Transcranial direct current stimulation given for at least 6 weeks may be of clinical benefit even in treatment-resistant depression. Results provide support for long-term effectiveness, safety, and feasibility of remotely supervised HA-tDCS and suggest a role for maintenance tDCS after acute treatment with tDCS, rTMS, or ECT.

Relationship between childhood physical abuse and clinical severity of treatment-resistant depression in a geriatric population

Introduction

We assessed the correlation between childhood maltreatment (CM) and severity of depression in an elderly unipolar Treatment-Resistant Depression (TRD) sample.

Methods

Patients were enrolled from a longitudinal cohort (FACE-DR) of the French Network of Expert TRD Centres.

Results

Our sample included 96 patients (33% of the overall cohort) aged 60 years or above, with a mean age of 67.2 (SD = 5.7). The majority of the patients were female (62.5%). The Montgomery and Asberg Depression Rating Scale (MADRS) and Quick Inventory Depression Scale-Self Report (QIDS-SR) mean scores were high, 28.2 (SD = 7.49) [MADRS score range: 0–60; moderate severity≥20, high severity≥35] and 16.5 (SD = 4.94) [IDS-SR score range: 0–27; moderate severity≥11, high severity≥16], respectively. Mean self-esteem scores were 22.47 (SD = 6.26) [range 0–30]. In an age- and sex-adjusted model, we found a positive correlation between childhood trauma (CTQ scores) and depressive symptom severity [MADRS (β = 0.274; p = 0.07) and QIDS-SR (β = 0.302; p = 0.005) scores]. We detected a statistically significant correlation between physical abuse and depressive symptom severity [MADRS (β = 0.304; p = 0.03) and QIDS-SR (β = 0.362; p = 0.005) scores]. We did not observe any significant correlation between other types of trauma and depressive symptom severity. We showed that self-esteem (Rosenberg scale) mediated the effect of physical abuse (PA) on the intensity of depressive symptoms [MADRS: b = 0.318, 95% BCa C.I. [0.07, 0.62]; QIDS-SR: b = 0.177, 95% BCa C.I. [0.04, 0.37]]. Preacher & Kelly’s Kappa Squared values of 19.1% (k² = 0.191) and 16% (k² = 0.16), respectively for the two scales, indicate a moderate effect.

Conclusion

To our knowledge, this is the first study conducted in a geriatric TRD population documenting an association between childhood trauma (mainly relating to PA) and the intensity of depressive symptoms.

Reversal of a Treatment-Resistant, Depression-Related Brain State with the Kv7 Channel Opener Retigabine

Neuroinflammation is associated with increased vulnerability to diverse psychiatric conditions, including treatment-resistant major depressive disorder (MDD). Here we assessed whether high fat diet (HFD) induced neuroinflammation may be suitable to model a treatment-resistant depressive-like brain state in mice. Male and female mice were fed a HFD for 18 weeks, followed by quantitation of glucose tolerance, inflammatory markers of brain tissue (TNFα, IL-6, IL-1β, Iba-1), neural excitability in the prelimbic cortex (PLC), as well as assessment of emotional reactivity and hedonic behavior in a battery of behavioral tests. In addition, we assessed the behavioral responsiveness of mice to fluoxetine, desipramine, ketamine, and the Kv7 channel opener and anticonvulsant retigabine. HFD exposure led to glucose intolerance and neuroinflammation in male mice, with similar but non-significant trends in females. Neuroinflammation of males was associated with anxious-depressive-like behavior and defects in working memory, along with neural hyperexcitability and increased I_h currents of pyramidal cells in the PLC. The behavioral changes were largely resistant to chronic treatment with fluoxetine and desipramine, as well as ketamine. By contrast, retigabine (also known as ezogabine) normalized neural excitability and I_h currents recorded from slices of HFD-treated animals and significantly ameliorated most of the behavioral impairments, without effects in control diet exposed animals. Thus, treatment resistant depressive-like brain states that are associated with chronic neuroinflammation may involve hyperexcitability of pyramidal neurons and may be effectively treated by retigabine.

Large falcine meningioma presented as treatment-resistant depression: A case report

Large intracranial tumour may present only with psychiatric symptoms without any neurological deficits. Delay in surgical treatment may significantly affect the quality of life in these patients. We report a case of a young engineering student who was diagnosed as treatment-resistant depression without initial neuroimaging study. Further neuroimaging studies revealed he has a large falcine meningioma. His psychiatric symptoms resolved following surgical resection of the tumour. We emphasized the importance of initial neuroimaging study in young patients presenting with psychiatric symptoms.

The impact of childhood adversity on suicidality and clinical course in treatment-resistant depression

BACKGROUND

Childhood adversity is a risk factor for the development of depression and can also affect clinical course. We investigated this specifically in treatment-resistant depression (TRD).

METHODS

One hundred and thirty-seven patients with TRD previously admitted to an inpatient affective disorders unit were included. Clinical, demographic and childhood adversity (physical, sexual, emotional abuse; bullying victimization, traumatic events) data were obtained during admission. Associations between childhood adversity, depressive symptoms and clinical course were investigated.

RESULTS

Most patients had experienced childhood adversity (62%), with traumatic events (35%) and bullying victimization (29%) most commonly reported. Childhood adversity was associated with poorer clinical course, including earlier age of onset, episode persistence and recurrence. Logistic regression analyses revealed childhood adversity predicted lifetime suicide attempts (OR 2.79; 95% CI 1.14, 6.84) and childhood physical abuse predicted lifetime psychosis (OR 3.42; 95% CI 1.00, 11.70).

LIMITATIONS

The cross-sectional design and retrospective measurement of childhood adversity are limitations of the study.

CONCLUSIONS

Childhood adversity was common amongst these TRD patients and was associated with poor clinical course, psychosis and suicide attempts. Routine assessment of early adversity may help identify at risk individuals and inform clinical intervention.

High-frequency rTMS treatment increases white matter FA in the left middle frontal gyrus in young patients with treatment-resistant depression

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) is an effective treatment for treatment-resistant depression (TRD), but its therapeutic mechanisms are unclear. White matter abnormalities are thought to cause network dysfunction underlying TRD. Diffusion tensor imaging (DTI) is an ideal tool for examining neural connections and the integrity of white matter. Few studies have used DTI to investigate the impact of rTMS on alterations of whiter matter in TRD.

METHOD

30 young treatment-resistant unipolar depression patients (19 males and 11 females) were enrolled in a double-blind, randomized high-frequency (15 Hz) rTMS treatment study. Seventeen patients were treated with real stimulation, and 13 were treated with sham stimulation. White-matter fractional anisotropy (FA) was evaluated using voxel-based analysis (VBA) of FA maps derived from DTI before and after treatment. Twenty-five age- and gender-matched subjects were examined as a control group.

RESULTS

In an exploratory VBA method, clusters of fifty voxels or greater that survived a family-wise error (FWE)-corrected threshold of p<0.05 were considered significant. The results revealed significantly reduced FA in the left middle frontal gyrus, with peak coordinates [-18 46 -14] in TRD patients. This reduced FA was significantly improved after active rTMS treatment, but not sham stimulation. FA increases were correlated with decreased depressive symptoms.

LIMITATIONS

This study requires replication and further clarification in a larger patient population, and optimization of stimulation locations and methods.

CONCLUSIONS

These results suggest that the efficacy of rTMS on TRD is related to increased white-matter FA in the left middle frontal gyrus.