Multiple sclerosis is chronic and progressive disorder of central nervous system, in which different psychiatric diagnosis comorbit in 75% with neurological symptoms. The reasons of depressive disorders are still not precisely known. Psychiatric disorders are often comorbid with neurological disorders and also influence diagnosis and treatment, more often than in other somatic illnesses. It is worth to emphasize that psychic disturbances are a consequence of neurological disorders but can also be primary sign of the disease. Especially emotional disorders and cognitive impairment are characteristic to patients with multiple sclerosis. Emotional, behavioural disorders and cognition dysfunction are often a result of pharmacotherapy of neurological disorders. Psychiatric disorders are often met in patients with autoimmunological disorders, what is more corticosteroid treatment may worsen the symptoms. Depressive disorders, especially serious and moderate episodes, occur twice more frequent than in general population. Following some authors patients suffering from multiple sclerosis and psychiatric disorders present deeper cognitive function impairment, poorer life quality and motor abilities as well as have worse treatment response. Although cognitive functions’ worsening occurs in half number of multiple sclerosis patients, dementia appears in few cases. Psychiatric disorders commonly comorbit with multiple sclerosis have adverse influence on everyday functioning.