Background:
The functioning of a person affected with a chronic illness within a family is a complex and many-sided issue. The illness produces an adaptive mechanism, and the ultimate goal of all adaptive measures is to deal with the new situation. The present research was intended to determine the psychological and clinical factors underly-ing the correct functioning of families with a multiple sclerosis sufferer.

Participants and procedure:
The research covered 108 families (216 persons) divided into three groups. We used an interview, the FACES IV questionnaire, the Dyadic Adjustment Scale, the Berlin Social Support Scales, the Coping Inventory for Stressful Situations, the Acceptance of Illness Scale, the Beck Depression Scale, the Mini-Mental State Exami-nation, the Controlled Oral Word Association Test, Raven’s Progressive Matrices, and the Similarities task from the Wechsler Adult Intelligence Scale.

Results:
The results of the research showed a significant difference in how family life was assessed by the three groups regarding cohesion and flexibility. A significant difference also related to communication and family life satis-faction. The best fit with the data was shown by the model incorporating two groups of predictors – global psy-chological variables (family variables) and individual psychological variables.

Conclusions:
Based on the research, it is highly probable that the majority of families with multiple sclerosis sufferers adjust relatively well to the disease. Despite chronic illness, a family can function correctly, but this largely depends on its ability to cope with stress. Clinical parameters of the illness, such as the degree of disability, proved to be irrelevant as predictors. It was also established that a system’s functioning depends on the mental condition of the healthy care-giving spouse. The patient’s cognitive impairment, especially his/her executive deficits, was found to be important.