Multiple sclerosis (MS) is the most common demyelinating disease of the central nervous system, especially young adults. Although MS is usually looked on as a disorder of the sensory and motor systems it can also be associated with emotional dysfunctions and changes in personality. The depression, bipolar disorders, euphoria, and pathological laughing and crying are most frequently associated with the disease. Authors present a review of current opinions on pathogenesis, diagnostic criteria and treatment of emotional problems in MS patients.