Multiple sclerosis and depression are linked, a study says

Jenny Feng, MD, a clinical associate at Cleveland Clinic Mellen Center for MS Treatment and Research, Ohio, lead a study on multiple sclerosis (MS) and concluded that depression is a symptom that indicates a relapse of the demyelinating disease.

Multiple sclerosis can be either progressive, with symptoms that build continuously, or relapsing-remitting, with symptoms appearing and disappearing. MS is a disease with an unclear cause. It is believed to be either autoimmune, with the immune system attacking the myelin or a failure of the cells responsible for producing the myelin.

Myelin is the fatty insulator of the nerve cell axons that acts as an enhancer for the electricity produced by the neuron. When impaired, the nervous system can’t work properly. The information can’t be forwarded. MS patients struggle with physical, mental, and psychiatric impairments.

The study observed 2500 MS patients and the differences between those experiencing depression, and those who didn’t. Tests measuring processing speed, walking speed, and manual dexterity in both categories proved that patients who were struggling with depression had lower scores on those neuro-performance measures.

Confronting those results with MRI imaging proved there is a strong link between depression and newly appeared contrast-enhancing lesions (CEL) on the brain. “Our results suggest that depression is not merely a reactive symptom but indicates increased risk of future MS disease activity,” say the researchers.

It isn’t sure how the process works. Is it the lesions that cause depression? The investigators can’t be sure of it. Inflammatory, psychosocial, and neurodegenerative factors are known to generate and worsen the symptoms of depression. And people with MS meet all these factors. But does the process of demyelinating itself cause depression too?  Or is it that depression influences MS?

“Depression isn’t just a neuropsychiatric disease. It may have effects on MS, especially with regards to performance in neurological function testing,” said Feng. But the accurate explanation “is not clear.” Further research is needed.