Quality of life and temperament factors in schizophrenia: comparative study of patients, their siblings and controls.

This study aimed to determine which temperament factors are associated with quality of life (QOL) in schizophrenia based on a triplet design comparing patients with their non-affected siblings and healthy control subjects. Forty-seven DSM-IV clinically stable schizophrenia outpatients, 47 non-affected siblings, and 56 non-patients matched for gender and age were evaluated using the Tridimensional Personality Questionnaire and the Quality of Life Enjoyment and Life Satisfaction Questionaire. As expected, schizophrenia patients reported significantly poorer QOL in most specific domains and in general. They also revealed significantly higher scores on harm avoidance and scored lower on reward dependence, than both their siblings and controls. Tridimensional Personality Questionnaire temperament factors revealed no differences between the controls and the siblings. When differences between patients, their siblings and controls were adjusted for gender, age at examination, and education, ANOVA demonstrated that temperament factors contributed to poor satisfaction with physical health, social relationships and subjective feelings in schizophrenia patients. Harm avoidance was associated with general QOL independent of severity of psychopathology. Thus, this study suggests that temperament factors that are not necessarily part of the deterioration process of the illness are associated with the quality of life of schizophrenia patients. These and other non-illness related factors should be considered when evaluating quality of life outcomes in intervention studies.