Pathogenic Mechanisms of Depression in Multiple Sclerosis

Abstract

Patients with multiple sclerosis (MS) have an increased risk of developing depression as compared with healthy subjects and patients with many other chronic neurological conditions. The observation that depressive symptoms can precede the onset of neurological symptoms suggests that depression may be related to early disease-specific processes. Several pathogenic mechanisms have been proposed to explain the etiology of depression in patients with MS. This article reviews the current evidence for the contribution of lesional, autoimmune, iatrogenic, and psychosocial factors. It appears that the etiology of depression is multifactorial and varies in individual patients with MS.

Lifestyle factors, demographics and medications associated with depression risk in an international sample of people with multiple sclerosis

“…While it may be reactive to the diagnosis of a chronic illness, depression in MS is also likely to be endogenous, partly based on the link with sclerotic pathology in specific neurological territories [43]. In a study controlling for disease-related variables and demographics, people with MS had three times the risk of depression compared to those with rheumatoid arthritis, suggesting that these differences could in part be attributed to the biological impact of the disease process in MS. [41] Additionally there is a strong link between genetics and depression in the general population when people with MS are excluded; however, for people with MS who have depression there is not a clear genetic basis, adding further weight to the role of other contributing factors [44,45].…”

A 12-month prospective, observational study evaluating the impact of disease-modifying treatment on emotional burden in recently-diagnosed multiple sclerosis patients: The POSIDONIA study

“…While there has been concern that immunomodulatory treatment may induce depression [11], rigorous studies have failed to demonstrate an association between interferon-β or glatiramer acetate and depression [11]. Regarding the possibility of an improvement in depression and anxiety symptoms with DMT, data from the current study suggest such treatment may have a positive role to play.…”

“…The prevalence of depression among patients with MS has been estimated to be 11% to 50% [4][5][6][7][8][9], and anxiety to be 20% to 40% [4,5,8,9]. Causes of depression and anxiety in this patient population include MS-related processes, genetic and environment-related predisposition, normal grieving and adjustment to loss [10,11]. Although depression and anxiety tend to worsen as physical disability increases [12], psychiatric comorbidities such as depression and anxiety are frequently present at the time of MS diagnosis [2,3,8,13].…”

The Role of Environment and Lifestyle in Determining the Risk of Multiple Sclerosis

“…There is evidence that autoimmune mechanisms may influence the reproductive life and fertility of both sexes (Carp et al 2012;Ballester et al 2004;Geva et al 2004;Kay and Bash 1965;Nelson et al 1993;Silman and Black 1988). Similarly, subtle symptoms or depressive symptoms that can precede the onset of neurological symptoms could affect the desire to become a parent (Gout et al 2011;Vattakatuchery et al 2011). …”