Depression and anxiety are both more prevalent in patients with MS than in the general population. Smoking and alcohol use are also common in these patients. However, while these associations are well-known, they have not been extensively studied. In a study recenty published in Multiple Sclerosis, investigators discovered that alcohol dependence and smoking are independently linked to depression and anxiety in MS patients.1

Ahead, study co-author Ruth Ann Marrie, MD, PhD, Associate Professor of Internal Medicine (Neurology) at the University of Manitoba in Winnipeg, reflects on the findings and the wider impact of research into psychological comorbidities of MS.

How do smoking and alcohol dependence affect MS?

Dr. Marrie: Smoking appears to have multiple effects on MS. Smokers are at increased risk of developing MS. Among persons who are diagnosed with MS, those who continue to smoke appear to be at higher risk of developing progressive MS than those who quit, or do not smoke. We found that alcohol dependence and smoking were associated with increased odds of anxiety and depression. Alcohol dependence was also associated with an increased risk of developing subsequent depression, and depression was associated with incident alcohol dependence. We did not evaluate the reasons for these associations.

How should your findings impact the way physicians care for and counsel patients?

Dr. Marrie: An earlier longitudinal study found that smoking was associated with an increased risk of anxiety and depression in MS. Three cross-sectional studies evaluated the relationship between alcohol use and mental health in MS, but the findings were mixed. We were unable to find any other prior studies that had evaluated the risk of incident mental health disorders associated with alcohol dependence in people with MS. Our findings suggest that if physicians are able to assist persons with MS with smoking cessation, and reduction of alcohol use this may help to reduce the risks of depression and anxiety. Routine evaluation of health behaviors is important.

How would you characterize the current state of therapeutic innovation in MS, particularly regarding comorbidities and quality of life?

Dr. Marrie: Most studies of treatments for MS, whether they are disease-modifying or symptomatic, have excluded individuals with comorbidities for safety reasons. A secondary analysis of a telephone-based fatigue management intervention found that persons with diabetes responded to the intervention more slowly than those without diabetes, suggesting that comorbidity needs to be considered in the management of MS-related symptoms. To date, studies have not evaluated whether treating comorbidities such as diabetes could improve quality of life in MS. Such work would be worthwhile.

Do you have any take-home tips to offer your colleagues when it comes to MS and patient health?

Dr. Marrie: People with MS often have other health conditions that may affect outcomes. A systematic approach to inquiring about these conditions and health behaviors that may increase the risk of these comorbid conditions is important to ensure that all of these issues are addressed. Further, a team approach can provide the necessary support to address these complex issues. n

1. McKay KA, Tremlett H, Fisk JD, Patten SB, Fiest K, Berrigan L, Marrie RA. Adverse health behaviours are associated with depression and anxiety in multiple sclerosis: A prospective multisite study. Mult Scler. 2015 Aug 5.