Treatment resistant depression in the elderly: a review of its conceptualisation, management and relationship to organic brain disease

Implementation of intermittent theta burst stimulation compared to conventional repetitive transcranial magnetic stimulation in patients with treatment resistant depression: A cost analysis

Background

Repetitive transcranial magnetic stimulation (rTMS) is an evidence-based treatment for depression that is increasingly implemented in healthcare systems across the world. A new form of rTMS called intermittent theta burst stimulation (iTBS) can be delivered in 3 min and has demonstrated comparable effectiveness to the conventional 37.5 min 10Hz rTMS protocol in patients with depression.

Objectives

To compare the direct treatment costs per course and per remission for iTBS compared to 10Hz rTMS treatment in depression.

Methods

We conducted a cost analysis from a healthcare system perspective using patient-level data from a large randomized non-inferiority trial (THREE-D). Depressed adults 18 to 65 received either 10Hz rTMS or iTBS treatment. Treatment costs were calculated using direct healthcare costs associated with equipment, coils, physician assessments and technician time over the course of treatment. Cost per remission was estimated using the proportion of patients achieving remission following treatment. Deterministic sensitivity analyses and non-parametric bootstrapping was used to estimate uncertainty.

Results

From a healthcare system perspective, the average cost per patient was USD$1,108 (SD 166) for a course of iTBS and $1,844 (SD 304) for 10Hz rTMS, with an incremental net savings of $735 (95% CI 688 to 783). The average cost per remission was $3,695 (SD 552) for iTBS and $6,146 (SD 1,015) for 10Hz rTMS, with an average incremental net savings of $2,451 (95% CI 2,293 to 2,610).

Conclusions

The shorter session durations and treatment capacity increase associated with 3 min iTBS translate into significant cost-savings per patient and per remission when compared to 10Hz rTMS.

Changes in dorsolateral prefrontal connectivity after rTMS in treatment-resistant depression: a brain perfusion SPECT study

PURPOSE

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive and safe alternative to electroconvulsive therapy for treatment-resistant depression (TRD). After rTMS, changes in brain SPECT perfusion have been remotely identified within medial temporal limbic areas, while no local effects have been found within the left dorsolateral prefrontal cortex (DLPFC)-i.e. under the coil. Functional changes in connectivity may underlie these remote effects. Interestingly, functional connectivity has been recently investigated using perfusion SPECT, and abnormalities identified in TRD patients. The aim of the present study is to evaluate perfusion and connectivity SPECT changes in TRD patients after rTMS of the left DLPFC. We hypothesize that changes in DLPFC networks may explain remote hypoperfusions found after rTMS.

METHODS

Fifty-eight TRD patients underwent a brain SPECT before and after high-frequency rTMS of the left DLPFC. Whole-brain voxel-based changes in perfusion were evaluated with SPM8, and inter-regional correlation analysis performed to study left DLPFC functional connectivity (p < 0.005, corrected for cluster volume).

RESULTS

After rTMS, patients were significantly improved on Beck Depression Inventory score (p < 0.0001). Considering a 50% reduction threshold, 27 patients were identified as responders (47%). After rTMS, perfusion changes were not found locally within the left DLPFC, but remotely within the bilateral temporal lobes, including limbic areas. Inter-regional correlation SPECT analysis brings out a decrease of connectivity between the left DLPFC and both the cingulate/medial frontal cortex and bilateral medial temporal limbic areas, in relation with the clinical response.

CONCLUSIONS

rTMS of DLPFC in TRD patients leads to remote temporal hypoperfusions in relation with changes in functional connectivity between the DLPFC and the default mode network, especially including medial temporal limbic areas.

Anticholinergic Medication Use and Risk of Dementia Among Elderly Nursing Home Residents with Depression

OBJECTIVE

To examine the risk of dementia with anticholinergic use among elderly nursing home residents with depression.

DESIGN

Population-based nested case-control study.

SETTING

Population-based study involving 2007-2010 Minimum Data Set-linked Medicare data from all 50 states.

PARTICIPANTS

Medicare beneficiaries aged 65 years and older, diagnosed with depression, and no history of dementia as of 2007 (baseline period). Cases were identified as patients with incident dementia following the baseline period. For each case, four age- and sex-matched control subjects were selected using incidence density sampling.

MEASUREMENTS

Anticholinergic exposure was defined using Anticholinergic Drug Scale. Prescription of clinically significant anticholinergic medications (levels 2 and 3) 30 days preceding the event date formed the primary exposure. The primary outcome was dementia diagnosis, between January 1, 2008, and December 31, 2010. A conditional logistic regression model stratified on matched case-control sets was performed to assess dementia risk, after controlling for other risk factors.

RESULTS

The study sample included 28,388 cases diagnosed with dementia and 113,352 matched control subjects. After adjusting for other risk factors, clinically significant anticholinergic use was associated with significant risk of dementia (OR: 1.26; 95% CI: 1.22-1.29) compared with non-use. The findings remained consistent across levels of anticholinergic potency (level 2, OR: 1.37, 95% CI: 1.31-1.44; level 3, OR: 1.15, 95% CI: 1.10-1.19).

CONCLUSION

Use of clinically significant anticholinergic medications was associated with a 26% increase in risk of dementia among elderly nursing home residents with depression. With increasing safety concerns, there is a significant need to optimize anticholinergic use, especially for those who are at risk for dementia.

Antidepressant effectiveness of deep Transcranial Magnetic Stimulation (dTMS) in patients with Major Depressive Disorder (MDD) with or without Alcohol Use Disorders (AUDs): a 6-month, open label, follow-up study

INTRODUCTION

Co-occurrence of Major Depressive (MDD) and Alcohol Use Disorders (AUDs) is frequent, causing more burden than each disorder separately. Since the dorsolateral prefrontal cortex (DLPFC) is critically involved in both mood and reward and dysfunctional in both conditions, we aimed to evaluate the effects of dTMS stimulation of bilateral DLPFC with left prevalence in patients with MDD with or without concomitant AUD.

METHODS

Twelve MDD patients and 11 with concomitant MDD and AUD (MDD+AUD) received 20 dTMS sessions. Clinical status was assessed through the Hamilton Depression Rating Scale (HDRS) and the Clinical Global Impressions severity scale (CGIs), craving through the Obsessive Compulsive Drinking Scale (OCDS) in MDD+AUD, and functioning with the Global Assessment of Functioning (GAF).

RESULTS

There were no significant differences between the two groups in sociodemographic (age, sex, years of education and duration of illness) and baseline clinical characteristics, including scores on assessment scales. Per cent drops on HDRS and CGIs scores at the end of the sessions were respectively 62.6% and 78.2% for MDD+AUD, and 55.2% and 67.1% for MDD (p<0.001). HDRS, CGIs and GAF scores remained significantly improved after the 6-month follow-up. HDRS scores dropped significantly earlier in MDD+AUD than in MDD LIMITATIONS: The small sample size and factors inherent to site and background treatment may have affected results.

CONCLUSIONS

High frequency bilateral DLPFC dTMS with left preference was well tolerated and effective in patients with MDD, with or without AUD. The antidepressant effect of dTMS is not affected by alcohol abuse in patients with depressive episodes. The potential use of dTMS for mood modulation as an adjunct to treatment in patients with a depressive episode, with or without alcohol abuse, deserves further investigation.

Maintenance transcranial magnetic stimulation reduces depression relapse: a propensity-adjusted analysis

BACKGROUND

The effectiveness of repetitive transcranial magnetic stimulation (TMS) is well established while studies of maintenance TMS are lacking. We aim here to determine whether maintenance is associated to a decrease in the relapse rate of depression, following successful acute treatment.

METHODS

We enrolled 59 consecutive patients with pharmacoresistant depression who have responded (>50% decrease in symptom severity) up to 6 weeks of acute TMS treatment. These patients received either 20 weeks of maintenance TMS (n=37) or no additional TMS treatment (n=22). We performed propensity adjusted-analysis to examine the association between the relapse rate over this 20-week period and maintenance TMS. Propensity analysis eliminated differences in baseline characteristics between patient with and without maintenance TMS and approximated the conditions of random site-of-treatment assignment.

RESULTS

At 20 weeks, relapse rate was significantly different between the two groups (p=0.004, propensity analysis): 14 patients in the maintenance TMS group (37.8%) vs. 18 in the non-maintenance TMS group (81.8%), with an adjusted Hazard Ratio (HR)=0.288 (0.124-0.669).

CONCLUSIONS

Maintenance TMS was associated with a significantly lower relapse rate in patients with pharmacoresistant depression in routine practice among responders.

Disrupted regional homogeneity in treatment-resistant depression: a resting-state fMRI study

BACKGROUND

Using a newly developed regional homogeneity (ReHo) approach, we were to explore the features of brain activity in patients with treatment-resistant depression (TRD) in resting state, and further to examine the relationship between abnormal brain activity in TRD patients and specific symptom factors derived from ratings on the Hamilton Rating Scale for Depression (HRSD).

METHODS

24 patients with TRD and 19 gender-, age-, and education-matched healthy subjects participated in the fMRI scans.

RESULTS

1. Compared with healthy controls, decreased ReHo were found in TRD patients in the left insula, superior temporal gyrus, inferior frontal gyrus, lingual gyrus and cerebellumanterior lobe (culmen) (p<0.05, corrected). 2. Compared with healthy controls, increased ReHo were found in the left superior temporal gyrus, cerebellum posterior lobe (tuber), cerebellum anterior lobe (culmen), the right cerebellar tonsil and bilateral fusiform gyrus (p<0.05, corrected). 3. There was no correlation between the ReHo values in any brain region detected in our study and the patients' age, years of education, illness duration, HRSD total score and its symptom factors.

LIMITATION

The influence of antidepressants to the brain activity in TRD patients was not fully eliminated.

CONCLUSIONS

The pathogenesis of TRD may be attributed to abnormal neural activity in multiple brain regions.

Predictive value of brain perfusion SPECT for rTMS response in pharmacoresistant depression

PURPOSE

The aim of this study was to determine the predictive value of whole-brain voxel-based regional cerebral blood flow (rCBF) for repetitive transcranial magnetic stimulation (rTMS) response in patients with pharmacoresistant depression.

METHODS

Thirty-three right-handed patients who met DSM-IV criteria for major depressive disorder (unipolar or bipolar depression) were included before rTMS. rTMS response was defined as at least 50% reduction in the baseline Beck Depression Inventory scores. The predictive value of (99m)Tc-ethyl cysteinate dimer (ECD) single photon emission computed tomography (SPECT) for rTMS response was studied before treatment by comparing rTMS responders to non-responders at voxel level using Statistical Parametric Mapping (SPM) (p < 0.001, uncorrected).

RESULTS

Of the patients, 18 (54.5%) were responders to rTMS and 15 were non-responders (45.5%). There were no statistically significant differences in demographic and clinical characteristics (p > 0.10). In comparison to responders, non-responders showed significant hypoperfusions (p < 0.001, uncorrected) in the left medial and bilateral superior frontal cortices (BA10), the left uncus/parahippocampal cortex (BA20/BA35) and the right thalamus. The area under the curve for the combination of SPECT clusters to predict rTMS response was 0.89 (p < 0.001). Sensitivity, specificity, positive predictive value and negative predictive value for the combination of clusters were: 94, 73, 81 and 92%, respectively.

CONCLUSION

This study shows that, in pharmacoresistant depression, pretreatment rCBF of specific brain regions is a strong predictor for response to rTMS in patients with homogeneous demographic/clinical features.

Magnetization transfer imaging reveals the brain deficit in patients with treatment-refractory depression

BACKGROUND

Studies on treatment resistant depression (TRD) using advanced magnetic resonance imaging techniques are very limited.

METHODS

A group of 15 patients with clinically defined TRD and 15 matched healthy controls underwent magnetization transfer imaging (MTI) and T1-weighted (T1W) imaging. MTI data were processed and analyzed voxel-wised in SPM2. A voxel based morphometric (VBM) analysis was performed using T1W images.

RESULTS

Reduced magnetization transfer ratio was observed in the TRD group relative to normal controls in the anterior cingulate, insula, caudate tail and amygdala-parahippocampal areas. All these regions were identified within the right hemisphere. VBM revealed no morphological abnormalities in the TRD group compared to the control group. Negative correlations were found between MRI and clinical measures in the inferior temporal gyrus.

LIMITATIONS

The cross-sectional design and small sample size.

CONCLUSIONS

The findings suggest that MTI is capable of identifying subtle brain abnormalities which underlie TRD and in general more sensitive than morphological measures.

A magnetic resonance imaging study of the entorhinal cortex in treatment-resistant depression

Despite a growing interest in this area, we continue to lack an understanding of the pathophysiology of depression and of treatment-resistant depression (TRD) in particular. The role of the medial temporal lobe, particularly the hippocampus, has been widely implicated in the aetiology of depression. However, related structures such as the entorhinal cortex have not been systematically examined. This research study aimed to examine possible abnormalities in the volume of the entorhinal cortex (ERC) in TRD patients. A group of 45 TRD patients and 30 healthy age- and sex-matched controls underwent magnetic resonance imaging (MRI). ERC volumes were manually traced from MRI data using ANALYZE software. An analysis of variance was conducted between subject groups and in the sexes separately while controlling for the effects of brain size via intracranial volume (ICV). Results revealed significant reductions in the volume of the left ERC of female patients. Although preliminary, our findings suggest that anatomical abnormalities in the ERC may confer vulnerability to treatment resistance. Confirmatory longitudinal studies are required to determine whether these abnormalities predate the onset of depression or are the result of a more chronic, treatment-resistant course of illness.

[Validity of vascular depression as a specific diagnostic: a review]

INTRODUCTION

A number of authors have suggested that cerebrovascular disease may predispose, precipitate, or perpetuate some geriatric depressive syndromes. These "vascular depressions" may result from damage of striato-pallido-thalamo-cortical pathways which frequently occurs in cerebrovascular disease.

METHOD

We have searched the English and French literature published between 1996 (when the "vascular depression" hypothesis was first stated) and December 2004 through the Medline computer database and examined the validity of the concept of "vascular depression" thanks to four levels of validity: face validity, descriptive validity, construct validity and predictive validity. The face validity is the extent to which experts agree about the existence of a nosological entity.

RESULTS

The reviews published in this field broadly support the concept of "vascular depression" as a specific disorder. However many authors highlighted the fact that depression has been shown to precede vascular diseases and that depression and vascular diseases may both share some pathogenic or genetic determinants. These interactive and co-morbid relationships between depression and cerebrovascular diseases are difficult to disentangle. The descriptive validity refers to the degree of the clinical specificity of a disorder. It appears only moderate regarding the clinical studies carried out on this issue. However, a late-onset, the absence of a family history of mental illness, the lack of insight, lassitude, psychomotor retardation, a greater disability and particular neuropsychological dysfunctions may be associated with vascular depression. The construct validity, which refers to the degree to which the physiopathological processes involved in an illness are understood, appears difficult to establish because of the complex interactive relationships between cerebrovascular disease and depression. However, cerebrovascular diseases may contribute to the occurrence of depressive symptoms independently of its psychosocial burden. The predictive validity refers to the degree to which a syndrome is characterized by a specific response to treatment or a specific natural history. As regards response to treatment, vascular depression appears rather specific in the sense of a worse response to antidepressants and electroconvulsive therapy. The studies on the natural history of vascular depression lead to inconsistent results. According to some authors, this relative resistance to treatment may be explained by structural rather than functional, and thus potentially irreversible disruption in neural networks.

CONCLUSION

In conclusion, the systematic review of the validity of vascular depression broadly supports this concept. However, further studies are needed to decipher the relationships between depression and cerebrovascular disease. Finally, we suggest that it could be more relevant for future researches in this field if the diagnostic criteria for vascular depression were narrowed and required the presence of both neuro-imaging changes and cerebrovascular disease.

Neuropathological evidence for ischemia in the white matter of the dorsolateral prefrontal cortex in late-life depression

BACKGROUND

Signal hyperintensities on magnetic resonance imaging in late-life depression are associated with treatment resistance and poor outcome. These lesions are probably vascular in origin and proposed sites for vascular damage include the dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC).

METHODS

We therefore examined white matter in these areas for microvascular disease and evidence of ischemia using intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1). We obtained postmortem tissue from elderly depressed (n = 20) and control (n = 20) subjects and blindly rated microvascular disease and ICAM-1 and VCAM-1 amount using quantitative image analysis in sections of the DLPFC, ACC and occipital cortex (OC; control area).

RESULTS

We found a significant increase in ICAM-1 in the deep white matter of the DLPFC in the depressed group (p = 0.01) and a trend towards an increase for VCAM-1 (p = 0.10). In the gyral white matter there was a trend towards significance for both molecules (p = 0.07 and 0.10). No differences were found in the ACC or OC or for microvascular disease in any area.

CONCLUSIONS

These findings are consistent with white matter ischemia in the DLPFC and lend support to the 'vascular depression' hypothesis. They implicate the DLPFC as an important site in the pathogenesis of late-life depression and have major implications for the understanding and management of late-life depression and raise the possibility of novel treatments being introduced in the future.

Treatment-resistant depression in late life

Treatment resistance is reported in up to 40% of older patients with major depression. Before labeling an episode of depression as treatment resistant, it is important to ensure that the diagnosis is correct and that the patient has received and adhered to an adequate dose of treatment for an appropriate length of time. It is also important to assess the patient for comorbid physical and psychiatric conditions that can contribute to treatment resistance. In patients who do not experience remission of symptoms with an adequate trial of medication, the following options can be considered: augmenting the antidepressant with a drug that is not primarily an antidepressant, adding a second antidepressant to the first, switching to a different antidepressant medication, or switching to electroconvulsive therapy. This paper reviews the concept of treatment-resistant depression and discusses its assessment and management in the elderly. The author concludes that when a systematic stepped-care approach to treatment is followed, most older patients with major depression will experience remission of symptoms.

Nonresponse to first-line pharmacotherapy may predict relapse and recurrence of remitted geriatric depression

The authors examined whether nonresponse to first-line pharmacotherapy was associated with an increased probability of relapse or recurrence following remission of an episode of geriatric depression. The study group consisted of 74 elderly patients whose index episode of nonpsychotic unipolar major depression had responded to antidepressant pharmacotherapy. In 6 of these patients, the depressive episode had not responded to first-line pharmacotherapy (8 weeks of nortriptyline, including 2 weeks of adjunctive lithium) but it had responded to second-line treatment (phenelzine with or without adjunctive lithium). The 74 patients were maintained on acute doses of the medications that had led to response and were followed for 2 years or until relapse or recurrence, whichever occurred first. The cumulative probability of relapse or recurrence was 67% for patients who responded to second-line treatment compared with 18% for patients who responded to first-line treatment (P = 0.0003). As expected, mean time to response was significantly longer for patients who responded to second-line treatment but this factor did not account for the difference in outcome between the two groups. These findings suggest that pharmacotherapy resistance may constitute a risk factor for relapse or recurrence of remitted geriatric depression, even when patients are maintained on the medication that they eventually respond to.

Nortriptyline in geriatric depression resistant to serotonin reuptake inhibitors: case series

Research on treatment-resistant depression in the elderly has been limited, and recommendations for clinical management have often been extrapolated from studies using nongeriatric patients. This report describes a series of 10 elderly patients with refractory depression who were treated with nortriptyline after failing to respond to an adequate trial of a serotonin reuptake inhibitor. Seven (70%) of the patients responded to the addition or substitution of nortriptyline. All seven of the responders have remained on nortriptyline for maintenance therapy, none of whom have experienced recurrence of their depression after an average treatment duration of 1 year. Response to nortriptyline occurred in about 4 weeks in most patients. The mean daily dose of nortriptyline was 54 mg, and the mean plasma level was 97 ng/mL. Minor side effects occurred in three patients. No patients developed significant electrocardiogram changes. Nortriptyline, possibly due to its different mechanism of action, may be effective as either an adjunctive or replacement antidepressant in some cases of geriatric depression that are resistant to serotonin reuptake inhibitors.

Transtornos depressivos na doença de Alzheimer: diagnóstico e tratamento

Transtornos do humor afetam uma porcentagem considerável de indivíduos com doença de Alzheimer, em algum ponto da evolução da síndrome demencial. Pode ser uma condição difícil de se detectar, dependendo da gravidade do acometimento cognitivo. Na presença de manifestações depressivas leves ou atípicas, a observação da evolução, associada ou não ao emprego de técnicas não-farmacológicas, é a abordagem inicial mais recomendável; na vigência de depressão moderada a grave, o emprego de psicofármacos pode fazer-se necessário. Embora haja evidências dos benefícios advindos do tratamento da depressão em pacientes com demência, avaliações formais da sua eficácia nesses pacientes são limitadas. A escolha do antidepressivo depende muito mais do seu perfil de tolerabilidade, das condições clínicas associadas e das características individuais do paciente. Os inibidores seletivos da recaptação de serotonina são usualmente as drogas de primeira opção, pelo perfil mais adequado de segurança, tolerabilidade e facilidade posológica. Em situações especiais, devem ser considerados os potenciais terapêuticos das novas drogas ou mesmo dos medicamentos tradicionais. O artigo revê a literatura dos últimos dez anos, enfocando particularidades do diagnóstico da depressão em pacientes com doença de Alzheimer, bem como diretrizes para uma prescrição segura.

Poor prognosis of depression in elderly people: causes and actions

Depression is the most common mental health problem of older people. It is a serious disorder which can lead to persistent suffering, increased mortality, from both suicide and general medical causes, and poorer overall health. Although presenting symptoms are similar in all age groups there are different aetiological pathways. In older people the waning effect of genetic predisposition to affective disorder may be replaced by subcortical brain abnormalities of presumed vascular aetiology. These may influence prognosis. Depression in later life is often under-diagnosed and under-treated; these two factors are the main hurdles to an improved prognosis. Antidepressant treatment should be tailored to the patient and works best when combined with psychological therapy, but the latter treatment modality is woefully neglected in later life psychiatry. Improvements in prognosis are unlikely to come from new revolutionary treatments but from vigorous treatment in the acute phase, continuation after recovery for at least 12-18 months and long-term maintenance treatment for those at high risk of recurrence.