Depression and anxiety in multiple sclerosis. Review of a fatal combination

Depression and anxiety are the most frequent neuropsychiatric symptoms of multiple sclerosis (MS), an autoimmune-mediated demyelinating neurodegenerative disease. Their prevalence is 25-65% and 20-54%, respectively, often associated with chronic fatigue and cognitive impairment, but usually not correlated with motor and other deficits, suggesting different pathophysiological mechanisms. Both disorders often arise before MS diagnosis, lead to faster disability and impair the quality of life. Risk factors are (young) age, genetic and family history burden. While no specific neuropathological data for depression (and anxiety) in MS are available, modern neuroimaging studies showed bilateral fronto-temporal, subcortical and limbic atrophies, microstructural white matter lesions and disruption of frontoparietal, limbic and neuroendocrine networks. The pathogenesis of both depression and anxiety in MS is related to shared mechanisms including oxidative stress, mitochondrial dysfunction, neuroinflammation and neuroendocrine mechanisms inducing complex functional and structural brain lesions, but they are also influenced by social and other factors. Unfortunately, MS patients with anxiety, major depression or suicidal thoughts are often underassessed and undertreated. Current treatment, in addition to antidepressant therapy include transcranial magnetic stimulation, cognitive, relaxation, dietary and other healthcare measures that must be individualized. The present state-of- the-art review is based on systematic analysis of PubMed, Google Scholar and Cochrane Library until May 2024, with focus on the prevalence, clinical manifestation, neuroimaging data, immune mechanisms and treatment options. Depression and anxiety in MS, like in many other neuroimmune disorders, are related, among others, to multi-regional patterns of cerebral disturbances and complex pathogenic mechanisms that deserve further elucidation as a basis for early diagnosis and adequate management to improve the quality of life in this disabling disease.

Impact of Anxious and/or Depressive Reactive State on the Effectiveness of Rehabilitation of Patients with Multiple Sclerosis

Background and Objectives: Rehabilitation is a part of the comprehensive treatment of multiple sclerosis (MS). If present, psychological reactive states limit the results of the rehabilitation. The objectives were to determine the impact of psychological reactive states in these patients on the functionality obtained by rehabilitation and QoL, and to determine the connection between the objective and subjective evaluation. Materials and Methods: Based on the Hospital anxiety and depression scale, the patients were divided into a group with anxious and/or depressive reactive state and a group without the reactive state. The values of functional scores-the Berg Balance Scale (BBS) and the Expanded Disability Status Scale (EDSS), as well as the parameters of the QoL-Physical health Component Score (PCS) and the Mental health Component Score (MCS)-were determined at the beginning and at the end of the rehabilitation. Results: There was a statistically significant difference between the BBS, EDSS, PCS, and MCS groups at the beginning and the end of the rehabilitation in both groups. A statistically significant difference at the beginning and the end of the rehabilitation between the groups was found only in PCS and MCS. A highly statistically significant correlation between EDSS and PCS, and EDSS and MCS, was found only in the group without the reactive state. Conclusions: Although rehabilitation leads to an objective improvement of functionality in patients with MS, the presence of the anxious and/or depressive reactive state limits the results of rehabilitation and leads to discrepancies in the aforementioned objective assessment and the patient's subjective experience through the evaluation of their QoL.

Monoaminergic network dysfunction and development of depression in multiple sclerosis: a longitudinal investigation

BACKGROUND

Monoaminergic network dysfunction is thought to underpin depression in multiple sclerosis (MS) patients. However, longitudinal studies are lacking.

OBJECTIVES

Here, we investigated the association between development of depressive symptoms in MS and changes of resting-state functional connectivity (RS FC) within monoaminergic networks.

METHODS

Forty-nine MS patients without depression [Montgomery-Asberg Depression Scale (MADRS) ≤ 9] and 27 healthy controls underwent clinical and 3.0 T RS FC assessment at baseline and after a median follow-up of 1.6 years (interquartile range 1.0-2.1 years). Monoamine-related RS FC was derived by independent component analysis, constrained to PET atlases for dopamine, noradrenaline and serotonin transporters. Longitudinal changes of RS FC within monoaminergic networks and their correlations with MADRS scores were assessed.

RESULTS

At baseline, MS patients showed decreased RS FC vs healthy controls in all PET-guided monoaminergic networks in frontal, cingulate and cerebellar cortices, and increased RS FC in parieto-occipital regions. Fourteen (29%) MS patients developed depressive symptoms (MADRS > 9) at follow-up (D-MS) and exhibited widespread RS FC decrease over time in the PET-guided dopamine network, mainly in orbitofrontal, occipital, anterior cingulate and precuneal cortices compared to patients who did not develop depressive symptoms. In D-MS, decreased RS FC over time was also observed in parahippocampal and occipital regions of the PET-guided noradrenaline network. Decreased RS FC over time in dopamine and noradrenaline PET-guided networks correlated with concomitant increased MADRS scores (r = range - 0.65/- 0.61, p < 0.001).

CONCLUSIONS

The development of depressive symptoms in MS patients was associated with specific RS FC changes within the dopamine and noradrenaline networks.

Distinct hemodynamic and functional connectivity features of fatigue in clinically isolated syndrome and multiple sclerosis: accounting for the confounding effect of concurrent depression symptoms

PURPOSE

This study aims to identify common and distinct hemodynamic and functional connectivity (FC) features for self-rated fatigue and depression symptoms in patients with clinically isolated syndrome (CIS) and relapsing-remitting multiple sclerosis (RR-MS).

METHODS

Twenty-four CIS, 29 RR-MS patients, and 39 healthy volunteers were examined using resting-state fMRI (rs-fMRI) to obtain whole-brain maps of (i) hemodynamic response patterns (through time shift analysis), (ii) FC (via intrinsic connectivity contrast maps), and (iii) coupling between hemodynamic response patterns and FC. Each regional map was correlated with fatigue scores, controlling for depression, and with depression scores, controlling for fatigue.

RESULTS

In CIS patients, the severity of fatigue was associated with accelerated hemodynamic response in the insula, hyperconnectivity of the superior frontal gyrus, and evidence of reduced hemodynamics-FC coupling in the left amygdala. In contrast, depression severity was associated with accelerated hemodynamic response in the right limbic temporal pole, hypoconnectivity of the anterior cingulate gyrus, and increased hemodynamics-FC coupling in the left amygdala. In RR-MS patients, fatigue was associated with accelerated hemodynamic response in the insula and medial superior frontal cortex, increased functional role of the left amygdala, and hypoconnectivity of the dorsal orbitofrontal cortex, while depression symptom severity was linked to delayed hemodynamic response in the medial superior frontal gyrus; hypoconnectivity of the insula, ventromedial thalamus, dorsolateral prefrontal cortex, and posterior cingulate; and decreased hemodynamics-FC coupling of the medial orbitofrontal cortex.

CONCLUSION

There are distinct FC and hemodynamic responses, as well as different magnitude and topography of hemodynamic connectivity coupling, associated with fatigue and depression in early and later stages of MS.

Neuro-immune crosstalk in depressive symptoms of multiple sclerosis

Depressive disorders can occur in up to 50% of people with multiple sclerosis in their lifetime. If left untreated, comorbid major depressive disorders may not spontaneously remit and is associated with an increased morbidity and mortality. Conversely, epidemiological evidence supports increased psychiatric visit as a significant prodromal event prior to diagnosis of MS. Are there common molecular pathways that contribute to the co-development of MS and psychiatric illnesses? We discuss immune cells that are dysregulated in MS and how such dysregulation can induce or protect against depressive symptoms. This is not meant to be a comprehensive review of all molecular pathways but rather a framework to guide future investigations of immune responses in depressed versus euthymic people with MS. Currently, there is weak evidence supporting the use of antidepressant medication in comorbid MS patients. It is our hope that by better understanding the neuroimmune crosstalk in the context of depression in MS, we can enhance the potential for future therapeutic options.

Symptom Interconnectivity in Multiple Sclerosis: A Narrative Review of Potential Underlying Biological Disease Processes

Introduction

Fatigue, cognitive impairment, depression, and pain are highly prevalent symptoms in multiple sclerosis (MS). These often co-occur and may be explained by a common etiology. By reviewing existing literature, we aimed to identify potential underlying biological processes implicated in the interconnectivity between these symptoms.

Methods

A literature search was conducted to identify articles reporting research into the biological mechanisms responsible for the manifestation of fatigue, cognitive impairment, depression, and pain in MS. PubMed was used to search for articles published from July 2011 to July 2021. We reviewed and assessed findings from the literature to identify biological processes common to the symptoms of interest.

Results

Of 693 articles identified from the search, 252 were selected following screening of titles and abstracts and assessing reference lists of review articles. Four biological processes linked with two or more of the symptoms of interest were frequently identified from the literature: (1) direct neuroanatomical changes to brain regions linked with symptoms of interest (e.g., thalamic injury associated with cognitive impairment, fatigue, and depression), (2) pro-inflammatory cytokines associated with so-called ‘sickness behavior,’ including manifestation of fatigue, transient cognitive impairment, depression, and pain, (3) dysregulation of monoaminergic pathways leading to depressive symptoms and fatigue, and (4) hyperactivity of the hypothalamic–pituitary-adrenal (HPA) axis as a result of pro-inflammatory cytokines promoting the release of brain noradrenaline, serotonin, and tryptophan, which is associated with symptoms of depression and cognitive impairment.

Conclusion

The co-occurrence of fatigue, cognitive impairment, depression, and pain in MS appears to be associated with a common set of etiological factors, namely neuroanatomical changes, pro-inflammatory cytokines, dysregulation of monoaminergic pathways, and a hyperactive HPA axis. This association of symptoms and biological processes has important implications for disease management strategies and, eventually, could help find a common therapeutic pathway that will impact both inflammation and neuroprotection.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40120-022-00368-2.

Prefrontal-amygdala emotion regulation and depression in multiple sclerosis

Depression is among the most common comorbidities in multiple sclerosis and has severe psychosocial consequences. Alterations in neural emotion regulation in amygdala and prefrontal cortex have been recognized as key mechanism of depression but never been investigated in multiple sclerosis depression. In this cross-sectional observational study, we employed a functional MRI task investigating neural emotion regulation by contrasting regulated versus unregulated negative stimulus perception in 16 persons with multiple sclerosis and depression (47.9 ± 11.8 years; 14 female) and 26 persons with multiple sclerosis but without depression (47.3 ± 11.7 years; 14 female). We tested the impact of depression and its interaction with lesions in amygdala-prefrontal fibre tracts on brain activity reflecting emotion regulation. A potential impact of sex, age, information processing speed, disease duration, overall lesion load, grey matter fraction, and treatment was taken into account in these analyses. Patients with depression were less able (i) to downregulate negative emotions than those without (t = −2.25, P = 0.012, β = −0.33) on a behavioural level according to self-report data and (ii) to downregulate activity in a left amygdala coordinate (t = 3.03, P_{Family-wise error [FWE]-corrected} = 0.017, β = 0.39). Moreover, (iii) an interdependent effect of depression and lesions in amygdala-prefrontal tracts on activity was found in two left amygdala coordinates (t = 3.53, p_FWE = 0.007, β = 0.48; t = 3.21, p_FWE = 0.0158, β = 0.49) and one right amygdala coordinate (t = 3.41, p_FWE = 0.009, β = 0.51). Compatible with key elements of the cognitive depression theory formulated for idiopathic depression, our study demonstrates that depression in multiple sclerosis is characterized by impaired neurobehavioural emotion regulation. Complementing these findings, it shows that the relation between neural emotion regulation and depression is affected by lesion load, a key pathological feature of multiple sclerosis, located in amygdala-prefrontal tracts.

The Effectiveness of Serious Games for Alleviating Depression: Systematic Review and Meta-analysis

BACKGROUND

Depression is a common mental disorder characterized by disturbances in mood, thoughts, or behaviors. Serious games, which are games that have a purpose other than entertainment, have been used as a nonpharmacological therapeutic intervention for depression. Previous systematic reviews have summarized evidence of effectiveness of serious games in reducing depression symptoms; however, they are limited by design and methodological shortcomings.

OBJECTIVE

This study aimed to assess the effectiveness of serious games in alleviating depression by summarizing and pooling the results of previous studies.

METHODS

A systematic review of randomized controlled trials (RCTs) was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. The search sources included 6 bibliographic databases (eg, MEDLINE, PsycINFO, IEEE Xplore), the search engine "Google Scholar," and backward and forward reference list checking of the included studies and relevant reviews. Two reviewers independently carried out the study selection, data extraction, risk of bias assessment, and quality of evidence appraisal. Results of the included studies were synthesized narratively and statistically, as appropriate, according to the type of serious games (ie, exergames or computerized cognitive behavioral therapy [CBT] games).

RESULTS

From an initial 966 citations retrieved, 27 studies met the eligibility criteria, and 16 studies were eventually included in meta-analyses. Very low-quality evidence from 7 RCTs showed no statistically significant effect of exergames on the severity of depressive symptoms as compared with conventional exercises (P=.12). Very low-quality evidence from 5 RCTs showed a statistically and clinically significant difference in the severity of depressive symptoms (P=.004) between exergame and control groups, favoring exergames over no intervention. Very low-quality evidence from 7 RCTs showed a statistically and clinically significant effect of computerized CBT games on the severity of depressive symptoms in comparison with no intervention (P=.003).

CONCLUSIONS

Serious games have the potential to alleviate depression as other active interventions do. However, we could not draw definitive conclusions regarding the effectiveness of serious games due to the high risk of bias in the individual studies examined and the low quality of meta-analyzed evidence. Therefore, we recommend that health care providers consider offering serious games as an adjunct to existing interventions until further, more robust evidence is available. Future studies should assess the effectiveness of serious games that are designed specifically to alleviate depression and deliver other therapeutic modalities, recruit participants with depression, and avoid biases by following recommended guidelines for conducting and reporting RCTs.

TRIAL REGISTRATION

PROSPERO International Prospective Register of Systematic Reviews CRD42021232969; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=232969.

The Effectiveness of Serious Games for Alleviating Depression: Systematic Review and Meta-analysis (Preprint).. [DOI: 10.2196/preprints.32331]

BACKGROUND

Depression is a common mental disorder characterized by disturbances in mood, thoughts, or behaviors. Serious games, which are games that have a purpose other than entertainment, have been used as a nonpharmacological therapeutic intervention for depression. Previous systematic reviews have summarized evidence of effectiveness of serious games in reducing depression symptoms; however, they are limited by design and methodological shortcomings.

OBJECTIVE

This study aimed to assess the effectiveness of serious games in alleviating depression by summarizing and pooling the results of previous studies.

METHODS

A systematic review of randomized controlled trials (RCTs) was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. The search sources included 6 bibliographic databases (eg, MEDLINE, PsycINFO, IEEE Xplore), the search engine “Google Scholar,” and backward and forward reference list checking of the included studies and relevant reviews. Two reviewers independently carried out the study selection, data extraction, risk of bias assessment, and quality of evidence appraisal. Results of the included studies were synthesized narratively and statistically, as appropriate, according to the type of serious games (ie, exergames or computerized cognitive behavioral therapy [CBT] games).

RESULTS

From an initial 966 citations retrieved, 27 studies met the eligibility criteria, and 16 studies were eventually included in meta-analyses. Very low-quality evidence from 7 RCTs showed no statistically significant effect of exergames on the severity of depressive symptoms as compared with conventional exercises (<i>P</i>=.12). Very low-quality evidence from 5 RCTs showed a statistically and clinically significant difference in the severity of depressive symptoms (<i>P</i>=.004) between exergame and control groups, favoring exergames over no intervention. Very low-quality evidence from 7 RCTs showed a statistically and clinically significant effect of computerized CBT games on the severity of depressive symptoms in comparison with no intervention (<i>P</i>=.003).

CONCLUSIONS

Serious games have the potential to alleviate depression as other active interventions do. However, we could not draw definitive conclusions regarding the effectiveness of serious games due to the high risk of bias in the individual studies examined and the low quality of meta-analyzed evidence. Therefore, we recommend that health care providers consider offering serious games as an adjunct to existing interventions until further, more robust evidence is available. Future studies should assess the effectiveness of serious games that are designed specifically to alleviate depression and deliver other therapeutic modalities, recruit participants with depression, and avoid biases by following recommended guidelines for conducting and reporting RCTs.

CLINICALTRIAL

PROSPERO International Prospective Register of Systematic Reviews CRD42021232969; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=232969

Depression and Fatigue in Patients With Multiple Sclerosis Have No Influence on the Parameters of Cognitive Evoked Potentials

PURPOSE

The purpose of this study was to examine if depression and fatigue affect event-related brain potentials (ERPs) in patients with relapsing-remitting multiple sclerosis, and to assess the significance of ERP as an indicator of cognitive impairment.

METHODS

A total of 81 relapsing-remitting multiple sclerosis patients and 32 healthy control subjects participated in the study. Cognitive functions were evaluated using a standard PASAT, the symbol digit modality test, and ERP. The degrees of depressive symptomatology and fatigue were assessed with Beck Depression Inventory, the Fatigue Severity Scale, and the Fatigue Impact Scale.

RESULTS

Fatigue and depression had a negative effect on the cognitive functions examined by neuropsychological tests. Depression and fatigue did not influence ERP amplitude and latency findings. Depression level was negatively correlated with symbol digit modality test score (r = -0.135, P < 0.05). Fatigue level was negatively correlated with the results for PASAT A (r = -0.225, P < 0.05) and PASAT B (r = -0.342, P < 0.01). Reaction time was positively associated with depression (r = 0.246, P = 0.01) and fatigue (r = 0.281, P = 0.01).

CONCLUSIONS

Depression and fatigue have no effect on ERP amplitude and latency, so they cannot participate in risk assessment for the development of cognitive impairment in patients with relapsing-remitting multiple sclerosis.

Effects of diminished positive mood and depressed mood upon verbal learning and memory among people with multiple sclerosis

Objective: Cognitive impairment affects as many as 65% of people with multiple sclerosis (PWMS), and memory impairment confers greater severity of disability and functional impairment. Depression is also common among PWMS, and lifetime prevalence rates are as high as 50%. Research has yet to clearly define the relationship between memory dysfunction and depression among PWMS, and may reflect incomplete assessment of depressive symptoms. The present study examined different aspects of depressive symptoms including anhedonia (i.e., diminished positive mood) and their relationships with verbal learning and memory among PWMS.Method: Participants were 48 healthy individuals and 96 PWMS. They were primarily Caucasian (90.3%) and female (75.0%). Participants completed the California Verbal Learning Test-2 (CVLT-2) to assess verbal learning and memory and the Chicago Multiscale Depression inventory to assess depressed mood (CMDI-Mood) and diminished positive mood (CMDI-DPM).Results: Linear regression revealed that the main effect of CMDI-DPM and the interaction of CMDI-DPM and CMDI-Mood significantly explained variance across learning, recall, and recognition CVLT-2 indices. Follow-up analyses indicated that CMDI-DPM was only significant in the absence of high CMDI-Mood scores. CMDI-Mood explained variance in only CVLT-2 Trial B.Conclusions: Depressed mood had little direct effect upon memory performance in PWMS. In the absence of severe depressed mood, higher levels of positive mood corresponded to better memory performance. However, the impact of diminished positive mood was rendered null among those endorsing high levels of depressed mood. These data may imply that anhedonia corresponds with poorer memory function among PWMS, and suggests that investigators and clinicians should assess multiple mood dimensions among PWMS.

Imaging and depression in multiple sclerosis: a historical perspective

PURPOSE

Patients affected with multiple sclerosis suffer from depression more frequently than the general population. Beyond psychosocial, genetic and immune-inflammatory factors, also the brain damage which is peculiar of multiple sclerosis has been claimed to have a role in the aetiology of depression in those patients. The study of this interesting relation has been implemented with both conventional and advanced magnetic resonance imaging techniques. The aim of this review is to provide a historical perspective on the link between multiple sclerosis-related depression and structural and functional brain damage.

METHODS

In this review, the results of the MRI studies regarding multiple sclerosis-related brain damage and the presence of depression are presented.

RESULTS

The findings of the reports reveal a link between brain pathology and depressive symptoms or the diagnosis of depression in multiple sclerosis.

CONCLUSIONS

Although a multifactorial aetiology has been theorized for depression and depressive symptoms in patients with multiple sclerosis, this review supports the hypothesis that the structural and functional brain impairment might substantially be amongst those factors. Thus, depression itself might be a symptom with a neuro-biological basis and not only the consequence of the disability derived from the neurological impairment.

Depression is associated with disconnection of neurotransmitter-related nuclei in multiple sclerosis

BACKGROUND

Depression is frequently associated with multiple sclerosis (MS). However, the biological background underlying such association is poorly understood.

OBJECTIVE

Investigating the functional connections of neurotransmitter-related brainstem nuclei, along with their relationship with white matter (WM) microstructure, in MS patients with depressive symptomatology (MS-D) and without depressive symptomatology (MS-nD).

METHODS

Combined resting-state functional magnetic resonance imaging (fMRI) and diffusion-weighted MRI (dMRI) study on 50 MS patients, including 19 MS-D and 31 MS-nD patients, along with 37 healthy controls (HC). Main analyses performed are (1) comparison between groups of raphe nuclei (RN)-related functional connectivity (FC); (2) correlation between RN-related FC and whole brain dMRI-derived fractional anisotropy (FA) map; and (3) comparison between groups of FA in the RN-related WM area.

RESULTS

(1) RN-related FC was reduced in MS-D when compared to MS-nD and HC; (2) RN-related FC positively correlated with FA in a WM cluster mainly encompassing thalamic/basal ganglia regions, including the fornix; and (3) FA in such WM area was reduced in MS-D.

CONCLUSION

Depressive symptomatology in MS is specifically associated to a functional disconnection of neurotransmitter-related nuclei, which in turn may be traced to a distinct spatial pattern of WM alterations mainly involving the limbic network.

Complementary therapies for clinical depression: an overview of systematic reviews

OBJECTIVES

As clinical practice guidelines vary widely in their search strategies and recommendations of complementary and alternative medicine (CAM) for depression, this overview aimed at systematically summarising the level 1 evidence on CAM for patients with a clinical diagnosis of depression.

METHODS

PubMed, PsycInfo and Central were searched for meta-analyses of randomised controlled clinical trials (RCTs) until 30 June 2018. Outcomes included depression severity, response, remission, relapse and adverse events. The quality of evidence was assessed according to Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) considering the methodological quality of the RCTs and meta-analyses, inconsistency, indirectness, imprecision of the evidence and the potential risk of publication bias.

RESULTS

The literature search revealed 26 meta-analyses conducted between 2002 and 2018 on 1-49 RCTs in major, minor and seasonal depression. In patients with mild to moderate major depression, moderate quality evidence suggested the efficacy of St. John's wort towards placebo and its comparative effectiveness towards standard antidepressants for the treatment for depression severity and response rates, while St. John's wort caused significant less adverse events. In patients with recurrent major depression, moderate quality evidence showed that mindfulness-based cognitive therapy was superior to standard antidepressant drug treatment for the prevention of depression relapse. Other CAM evidence was considered as having low or very low quality.

CONCLUSIONS

The effects of all but two CAM treatments found in studies on clinical depressed patients based on low to very low quality of evidence. The evidence has to be downgraded mostly due to avoidable methodological flaws of both the original RCTs and meta-analyses not following the Consolidated Standards of Reporting Trials and Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Further research is needed.

A complex relation between depression and multiple sclerosis: a descriptive review

BACKGROUND

Multiple sclerosis (MS) is a demyelinating neurodegenerative disease that affects central nervous system (CNS). MS patients are more likely to develop depressive symptoms than patients with other chronic diseases.

OBJECTIVE

In this review, we have analysed if there is a correlation between brain lesions (BL), structural damage (SD) and depressive symptoms (DS).

METHODS

We Searched on PubMed and Web of Science databases and screening references of included studied and some review article for additional citations. From initial 745 studies, only 9 met the inclusion criteria. All studies conducted research on 389 patients with MS associated with DS and 120 HC (healthy controls).

RESULTS

The selected researches highlighted the involvement of limbic system, the role of hippocampus and the impact of brain lesions on the emotional status of MS patients.

DISCUSSION

In the genesis of depression are implicated many mechanisms including genetic, biochemical, immunological and psychosocial factors, even if a prominent role in the onset of DS seem to be associated with structural and functional brain alterations.

Fronto-limbic disconnection in patients with multiple sclerosis and depression

Background:

The biological mechanism of depression in multiple sclerosis (MS) is not well understood. Based on work in major depressive disorder, fronto-limbic disconnection might be important.

Objective:

To investigate structural and functional fronto-limbic changes in depressed MS (DMS) and non-depressed MS (nDMS) patients.

Methods:

In this retrospective study, 22 moderate-to-severe DMS patients (disease duration 8.2 ± 7.7 years), 21 nDMS patients (disease duration 15.3 ± 8.3 years), and 12 healthy controls underwent neuropsychological testing and magnetic resonance imaging (MRI; 1.5 T). Brain volumes (white matter (WM), gray matter, amygdala, hippocampus, thalamus), lesion load, fractional anisotropy (FA) of fronto-limbic tracts, and resting-state functional connectivity (FC) between limbic and frontal areas were measured and compared between groups. Regression analysis was performed to relate MRI measures to the severity of depression.

Results:

Compared to nDMS patients, DMS patients (shorter disease duration) had lower WM volume (p < 0.01), decreased FA of the uncinate fasciculus (p < 0.05), and lower FC between the amygdala and frontal regions (p < 0.05). Disease duration, FA of the uncinate fasciculus, and FC of the amygdala could explain 48% of variance in the severity of depression. No differences in cognition were found.

Conclusion:

DMS patients showed more pronounced (MS) damage, that is, structural and functional changes in temporo-frontal regions, compared to nDMS patients, suggestive of fronto-limbic disconnection.

Mental Health Comorbidity in MS: Depression, Anxiety, and Bipolar Disorder

Among individuals with multiple sclerosis (MS), mental health comorbidities play a significant role in contributing to secondary disability and detracting from quality of life. This review examines current evidence surrounding three mental health issues of particular relevance to MS: depression, anxiety, and bipolar disorder. We review what is known of the prevalence, correlates, screening mechanisms, and current treatment of each issue and provide recommendations for future areas of research.

A systematic review of yoga for major depressive disorder

BACKGROUND

The purpose of this review was to investigate the efficacy and safety of yoga interventions in treating patients with major depressive disorder.

METHODS

MEDLINE, Scopus, and the Cochrane Library were screened through December 2016. Randomized controlled trials (RCTs) comparing yoga to inactive or active comparators in patients with major depressive disorder were eligible. Primary outcomes included remission rates and severity of depression. Anxiety and adverse events were secondary outcomes. Risk of bias was assessed using the Cochrane tool.

RESULTS

Seven RCTs with 240 participants were included. Risk of bias was unclear for most RCTs. Compared to aerobic exercise, no short- or medium-term group differences in depression severity was found. Higher short-term depression severity was found for yoga compared to electro-convulsive therapy; remission rates did not differ between groups. No short-term group differences occurred when yoga was compared to antidepressant medication. Conflicting evidence was found when yoga was compared to attention-control interventions, or when yoga as an add-on to antidepressant medication was compared to medication alone. Only two RCTs assessed adverse events and reported that no treatment-related adverse events were reported.

LIMITATIONS

Few RCTs with low sample size.

CONCLUSIONS

This review found some evidence for positive effects beyond placebo and comparable effects compared to evidence-based interventions. However, methodological problems and the unclear risk-benefit ratio preclude definitive recommendations for or against yoga as an adjunct treatment for major depressive disorder. Larger and adequately powered RCTs using non-inferiority designs are needed.

Fatigue and depression in multiple sclerosis: pharmacological and non-pharmacological interventions

Multiple sclerosis (MS) is a neuroinflammatory condition with a prominent progressive neurodegenerative facet that typically affects young- or middle-aged adults. Although physical disabilities have been in the foreground by being easier to assess, there is an increasing interest in mental disabilities and psychiatric co-morbidities, which have a disproportionally high impact on important outcome measures such as quality of life and occupational disability. In particular, cognitive impairment, depression and mental fatigue, which mutually interact with each other, seem to be of importance in this context. In recent decades, major efforts have been invested in developing more effective disease modulatory treatments. This has resulted in novel therapeutic options and awareness of the importance of early intervention. In comparison, good quality and adequately powered studies on symptomatic treatments of fatigue and psychiatric co-morbidities in MS are rare, and awareness of treatment options is much lower. We here review the existing evidence base for symptomatic treatment of fatigue and depression in MS patients. With regard to fatigue, off-label prescription of alertness improving drugs is common, in spite of all but absent evidence of efficacy. In contrast, a number of smaller studies suggest that physical exercise and fatigue management courses may have some clinical benefit. Very few studies have addressed the efficacy of antidepressants and non-pharmaceutical interventions specifically in MS patients. Therefore, treatment guidelines largely rely on data from non-MS populations. In the future, there is a strong motive to direct additional resources to the study of these important aspects of MS.

Hippocampal Neuroinflammation, Functional Connectivity, and Depressive Symptoms in Multiple Sclerosis

BACKGROUND

Depression, a condition commonly comorbid with multiple sclerosis (MS), is associated more generally with elevated inflammatory markers and hippocampal pathology. We hypothesized that neuroinflammation in the hippocampus is responsible for depression associated with MS. We characterized the relationship between depressive symptoms and hippocampal microglial activation in patients with MS using the 18-kDa translocator protein radioligand [(18)F]PBR111. To evaluate pathophysiologic mechanisms, we explored the relationships between hippocampal neuroinflammation, depressive symptoms, and hippocampal functional connectivities defined by resting-state functional magnetic resonance imaging.

METHODS

The Beck Depression Inventory (BDI) was administered to 11 patients with MS and 22 healthy control subjects before scanning with positron emission tomography and functional magnetic resonance imaging. We tested for higher [(18)F]PBR111 uptake in the hippocampus of patients with MS relative to healthy control subjects and examined the correlations between [(18)F]PBR111 uptake, BDI scores, and hippocampal functional connectivities in the patients with MS.

RESULTS

Patients with MS had an increased hippocampal [(18)F]PBR111 distribution volume ratio relative to healthy control subjects (p = .024), and the hippocampal distribution volume ratio was strongly correlated with the BDI score in patients with MS (r = .86, p = .006). Hippocampal functional connectivities to the subgenual cingulate and prefrontal and parietal regions correlated with BDI scores and [(18)F]PBR111 distribution volume ratio.

CONCLUSIONS

Our results provide evidence that hippocampal microglial activation in MS impairs the brain functional connectivities in regions contributing to maintenance of a normal affective state. Our results suggest a rationale for the responsiveness of depression in some patients with MS to effective control of brain neuroinflammation. Our findings also lend support to further investigation of the role of inflammatory processes in the pathogenesis of depression more generally.