The bidirectional effect of stress and functionality in multiple sclerosis and the interaction role of anxiety, coping and social support

Behavioral disorders in multiple sclerosis: a comprehensive review

Multiple sclerosis (MS) is a heterogenous autoimmune-mediated disease of the central nervous system (CNS) characterized by inflammation, demyelination and chronic progressive neurodegeneration. Among its broad and unpredictable range of neuropsychiatric symptoms, behavioral changes are common, even from the early stages of the disease, while they are associated with cognitive deficits in advanced MS. According to DSM-5, behavioral disorders include attention deficits, oppositional, defiant and conduct disorders, anxiety, panic, obsessive-compulsive disorders (OCD), disruptive and emotional disorders, while others include also irritability, agitation, aggression and executive dysfunctions. Approximately 30 to 80% of individuals with MS demonstrate behavioral changes associated with disease progression. They are often combined with depression and other neuropsychiatric disorders, but usually not correlated with motor deficits, suggesting different pathomechanisms. These and other alterations contribute to disability in MS. While no specific neuropathological data for behavioral changes in MS are available, those in demyelination animal models share similarities with white matter and neuroinflammatory abnormalities in humans. Neuroimaging revealed prefrontal cortical atrophy, interhemispheric inhibition and disruption of fronto-striato-thalamic and frontoparietal networks. This indicates multi-regional patterns of cerebral disturbances within the MS pathology although their pathogenic mechanisms await further elucidation. Benefits of social, psychological, behavioral interventions and exercise were reported. Based on systematical analysis of PubMed, Google Scholar and Cochrane library, current epidemiological, clinical, neuroimaging and pathogenetic evidence are reviewed that may aid early identification of behavioral symptoms in MS, and promote new therapeutic targets and strategies.

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.

Resilience, mental health, sleep, and smoking mediate pathways between lifetime stressors and Multiple Sclerosis severity

Intro

Lifetime stressors (e.g., poverty, violence, discrimination) have been linked to Multiple Sclerosis (MS) features; yet mechanistic pathways and relationships with cumulative disease severity remain nebulous. Further, protective factors like resilience, that may attenuate the effects of stressors on outcomes, are seldom evaluated.

Aim

To deconstruct pathways between lifetime stressors and cumulative severity on MS outcomes, accounting for resilience.

Methods

Adults with MS (N=924) participated in an online survey through the National MS Society listserv. Structural Equation Modeling was used to examine the direct and indirect effect of lifetime stressors (count/severity) on MS severity (self-reported disability, relapse burden, fatigue, pain intensity and interference), via resilience, mental health (anxiety and depression), sleep disturbance, and smoking.

Results

The final analytic model had excellent fit (GFI=0.998). Lifetime stressors had a direct relationship with MS severity (β=0.27, p<.001). Resilience, mental health, sleep disturbance, and smoking significantly mediated the relationship between lifetime stressors and MS severity. The total effect of mediation was significant (β=0.45).

Conclusions

This work provides foundational evidence to inform conceptualization of pathways by which stress could influence MS disease burden. Resilience may attenuate effects of stressors, while poor mental health, smoking, and sleep disturbances may exacerbate their impact. Parallel with usual care, these mediators could be targets for early multimodal therapies to improve disease course.