ABSTRACT
Emotional disturbances are common in multiple sclerosis (MS).[1-9] They consist of disturbances of affect, in which emotional expression may be blunted, flat, inappropriate, or labile and disturbances of mood, such as depression, mania, and anxiety.[10] The terms ‘affect’ and ‘mood’ are often used interchangeably, but the differences between them are important and have etiological, diagnostic, and treatment implications. Mood refers to a sustained and pervasive emotion that influences perception of self, others, and the world. Affect refers to more fluctuating changes in the outward esxpression of inner feeling states. The disorders of affect-euphoria, pathological laughing and weeping, and other frontal lobe syndromes-are direct consequences of the pathological process in MS, are highly characteristic features of the disease, and follow the same course as the other signs and symptoms of MS. There are effective treatments for pathological laughing and weeping and, to some extent, for the apathy associated with frontal lobe and subcortical syndromes. By contrast, the relationship between MS and the disorders of mood-major depressive disorder, dysthymic disorder, bipolar disorder, panic disorder, and generalized anxiety disorder-is multifactorial and complex, and the extent to which mood disorders are direct consequences of the disease process or psychological reactions to it remains unclear. Whatever their cause, however, mood disorders in MS are phenomenologically no different from mood disorders more generally and respond similarly to standard treatments.
