Measures
The dependent variable, the quality of the sibling relationship, was measured by the Positive Affect Index ( 23 ). Each item was rated on a 6-point scale (1, not at all; 6, extremely). Five items assessed the sibling's feelings toward the brother or sister with schizophrenia along the dimensions of trust, intimacy, understanding, fairness, and respect. A second set of five similar items assessed the sibling's perception of the ill sibling's feelings toward him or her. The items were summed for a total score. Possible scores ranged from 10 to 60, with higher scores indicating a higher-quality relationship. Overall, siblings reported feeling moderate levels of closeness (42.4±8.8). Cronbach's alpha of reliability was .92.