Depressive Symptoms Have Greater Negative Effect on MS Functional Outcomes Than Anxiety

In individuals with multiple sclerosis (MS), depressive symptoms are more disabling than symptoms of anxiety, and therefore require priority for treatment, according to results of a study published in the Journal of Neuropsychiatry and Clinical Neurosciences.

Depression and anxiety are common in patients with MS and contribute to the overall morbidity of the disease. Many patients experience symptoms of both mood disorders, which make it difficult to determine whether anxiety or depression is more disabling.

Sascha Gill, BSc, from the Department of Cognitive Neurology, Parkwood Institute, London, Ontario, Canada, and colleagues conducted a retrospective chart review of 128 patients with MS. They explored the relationship of the Hospital Anxiety and Depression Scale Depression subscale (HADS-D) and Anxiety subscale (HADS-A) to a number of functional outcomes, including employment status, fatigue, disability, and cognition, to establish which mood disorder should be given priority for treatment. The authors performed exploratory structural equation models to evaluate the effects of HADS-D and HADS-A on functional outcomes, which included the Expanded Disability Status Scale (EDSS), Fatigue Severity Scale score, and Symbol Digit Modalities Test performance.

Nearly 75% of the patient population were women, and the mean duration of the MS diagnosis was 12.21 years. Most patients (71.9%) had relapsing-remitting MS, followed by secondary progressive (23.4%) and primary progressive (4.7%). The median EDSS score was 3.0, and according to HADS criteria, 38% of the patients had depression and 57% had anxiety.

After controlling for covariate effects, the authors found that HADS-A was negatively associated with EDSS (β, −0.22; P <.05) and positively associated with vocation (β, 0.23; P <.05). However, HADS-D demonstrated a positive correlation with fatigue (β, 0.37; P <.05) and EDSS (β, 0.26; P <.05), but correlated negatively with vocation (β, −0.32; P <.05) and Symbol Digit Modalities Test (β, −0.28; P <.05).

The findings of this study are in contrast to those of previous studies, which found anxiety to be negatively associated with MS-related disability, fatigue, unemployment, and cognitive function. However, the overlap between anxiety and depression was rarely considered in these studies.

The authors noted a potential for a complex and dynamic relationship between depression and functional outcomes in MS, with greater dysfunction possibly increasing levels of depression. However, they contend that further research is necessary to delineate these relationships. They also noted that at higher anxiety levels, physical disability was lower, and that disability identity was associated with low psychological distress, perhaps reflecting an acceptance and adaptation to disability status.

The study was limited by its retrospective nature, which precluded identifying the direction of causality between mood and functional variables.

Disclosures: Dr Morrow has received honoraria for speaking, consulting, and advisory board participation from Biogen Idec, EMD Serono, Genzyme, Novartis, and Roche; she has served as site principal investigator for clinical trials for Genzyme, Novartis, and Roche; and she has received investigator-initiated trial funding from Genzyme. All other authors report no financial relationships with commercial interests.

Reference

Gill S, Santo J, Blair M, Morrow SA. Depressive symptoms are associated with more negative functional outcomes than anxiety symptoms in persons with multiple sclerosis [published online September 6, 2018]. J Neuropsychiatry Clin Neurosci. doi:10.1176/appineuropsych.18010011