Objectives. The poor quality of life in myasthenia gravis (MG) has been explained so far by reduced physical disability. The aim of the study was to assess the impact of psychological factors, such as mood, optimism, state and trait anxiety, on MG patients' quality of life and their adjustment to the disease.
Method. The disease severity was rated by a neurologist according to the Osserman and Oosterhuis criteria. In the psychological assessment the following instruments were used: the Quality of Life Questionnaire, Acceptance of Illness Scale, Life Orientation Test (LOT-R), the Beck Depression Inventory (BDI), State- and Trait-Anxiety Inventory (STAI), and the MG Disability Scale.
Results. Almost all of the quality of life components were diminished in MG. The quality of life in MG is associated with the patient 's daily functioning level and state anxiety intensity. A low state anxiety, positive mood and satisfactory functional status are propitious for the acceptance of illness in MG, comparable to that observed in other chronic disorders.
Conclusions. The quality of life and acceptance of illness in MG are associated not only with the patients' clinical status, but also with psychological factors. A comparison of the obtained data with earlier research findings suggests that participation in support groups may positively influence MG patients ' adjustment to the disease. The diagnosis of depression in MG cannot be based solely on somatic symptoms.