Comparative analysis of predictors of mental disorders in patients with multiple sclerosis: a longitudinal prospective study

Abstract

Recent years have been characterized by an increase in mental disorders among patients with multiple sclerosis (MS). However, the predictors of mental disorder development remain virtually unstudied. The purpose of the study: comparative analysis of predictors of mental disorders in MS patients. The study included 341 patients with MS and mental disorders. The control group consisted of 100 patients with MS without mental disorders. The follow-up period was 10 years. The following scales were employed: the Beck Depression Inventory, MFI-20, the Spielberger-Khanin anxiety scale, PASAT, the visual analogue pain scale (VAS), and EDSS; significant stressful events were recorded. The following were also taken into account: type of MS, clinically and radiologically isolated syndrome (CIS, RIS) preceding the development of MS, comorbid pathology, and use of disease-modifying therapies (DMTs). The diagnosis of mental disorders was established in accordance with ICD-10 criteria. Brain magnetic resonance imaging (MRI) was performed, and the diagnosis of MS was established by a radiologist and a neurologist. Multivariate models were developed using analysis of variance and multiple linear regression equations. Based on the mathematical multivariate models, predictors of the development of a number of mental disorders in MS were established, including depression, anxiety disorders, bipolar affective disorder, schizoaffective disorder, and organic delusional disorder. The key universal predictors of the development of all mental disorders in MS are: high asthenia with its subsequent increase, a high rate of MS progression, and high reactive anxiety with its subsequent increase. Furthermore, an individual set of additional predictors was identified for each mental disorder, including specific characteristics of the dynamics of multiple sclerosis lesions in the brain, the type of disease course and onset, the presence of pain syndrome, and the dynamics of cognitive impairment. The specific localization of demyelinating lesions is of particular importance for different mental disorders. The key universal predictors of mental disorders are characteristics associated with the course of MS: a high degree of asthenia with its further increase, a high rate of MS progression, and highly active MS (in patients with an established MS diagnosis), as well as the presence of multiple lesions on MRI, which supports their organic origin in mental disorders associated with MS.