Psychiatric symptomatology and psychopathology were assessed using the Brief Psychiatric Rating Scale [41]. This instrument, consisting of 18-items, was administered by trained clinical raters using face-to-face interviews, and assesses psychopathology across symptom domains including; thought disturbance, suspiciousness/hostility, anergia, activation, and anxiety/depression. Each item is rated on a scale ranging from 1 (not present) to 7 (extremely severe), and corresponds with the degree to which symptoms are endorsed [41]. Ratings are computed by summing across symptom domains; higher scores are indicative of more serious symptomatology (18 = minimum score; 112 = maximum score). The BPRS has an established factor structure with good psychometric properties [42], and has been widely used in psychiatric institutional and community-based research settings.
