Avaliação breve da psicossintomatologia: análise fatorial confirmatória da versão portuguesa do Brief Symptom Inventory 18 (BSI 18)

The Brief Symptom Inventory 18 (BSI 18), originally developed by Derogatis in 2001, is a questionnaire which aims to screen for psychological distress among community and clinical populations. People are asked to assess the intensity (from 0-Not at all to 4-Extremely) with which, in the last seven days, they have experienced eighteen manifestations of psychological distress. In the present study, we conducted the psychometric studies of the Portuguese version of the BSI 18, focusing on its factorial structure, validity, and reliability. The sample included two groups: a community group, which was comprised of 184 adults from the general population; and a clinical group, which was comprised of 141 adults with psychiatric diagnoses currently receiving psychological and/or psychiatric treatment. Participants answered four questionnaires: the BSI 18, the Beck Depression Inventory, the Zung Self-Rating Anxiety Scale, and the Brief COPE. Seventy-six participants answered the BSI 18 again, about four weeks after the first assessment. Confirmatory factor analyses were run in order to test several models presented in previous studies. We selected a first-order model with three dimensions: Somatization (manifestations of the automatically regulated systems, such as the gastrointestinal and cardiovascular systems), Depression (core symptoms of depressive disorders, such as dysphoric mood, anhedonia, hopelessness, and suicidal ideation), and Anxiety (symptoms indicating panic, such as nervousness, tension, restlessness, and apprehension). The BSI 18 was shown to have good validity (construct, convergent, discriminant, and criterion based on group differentiation) and reliability (internal consistency and temporal reliability). Considering this, the BSI 18 is useful in clinical and in research contexts.