Emotional disturbances are common in MS and consist of disturbances of mood
and disturbances of affect. The important mood disorders are major depress
ive disorder, dysthymic disorder, bipolar disorder, panic disorder, and gen
eralized anxiety disorder. Their relationship to MS is multi-factorial and
complex, and the extent to which they are direct consequences of the diseas
e process or psychological reactions to it remains unclear. Whatever their
cause, however, the symptoms of mood disorders in people with MS are no dif
ferent from the symptoms of mood disorders in people without MS, and respon
d just as well to standard treatments. The disorders of affect are euphoria
, pathological laughing and weeping, and other frontal lobe syndromes. Thes
e disorders result from demyelination, are some of the most characteristic
symptoms of MS, and have the same implications for treatment as do other as
pects of the disease. Mood and affective disturbances can cause enormous pa
in and suffering and lead to significant disruption of family, work, and so
cial life. Physicians who can identify, diagnose, treat, and manage mood an
d affective disturbances effectively and who can help their patients and fa
mily members acknowledge these difficulties, talk about them, and accept ps
ychiatric consultation and treatment can have a dramatic impact on the qual
ity of their lives. This paper outlines the symptoms and diagnostic criteri
a for mood disorders and affective disturbances, reviews current treatment
options, summarizes data from epidemiologic and pathophysiological studies,
and suggests areas for future research.