Abstract
Multiple sclerosis (MS) is an autoimmune disorder where the body attacks its own insulating myelin sheaths covering the nerve cells in the brain and spinal cord. MS patients show signs of mental illness via emotional blunting, liability, apathy, depression, irritability, and psychosis. Many psychiatrists have noted that the symptomatology of mood disorder is very similar to early signs of MS. The mechanism behind the relationship of depression with MS is not entirely understood at this point. However, through advancements in medical imaging techniques, there are now some leading explanations. One main explanation suggests that depression and memory disturbance are correlated to the demyelination within the limbic system caused by MS. Studies showed that following a diagnosis of MS, the rates of depression are significantly elevated in patients. Several studies noted a lifetime prevalence of major depression in >50% of MS patients. These studies foreshadow that depression is a very important clinical harbinger of active demyelination in MS patients. Depression may hint at which subgroup or stage the MS patient is in, without needing to wait for dramatic physical signs or symptoms to commence. Future physicians may be able to use depression as a prodrome for multiple sclerosis and narrow down the prognosis of their patients, treating them earlier.