The Usefulness of the Brief Symptom Inventory 18 (BSI-18) in Psychotherapeutic Patients

The BSI-18, an abridged version of the Brief Symptom Inventory of Derogatis, contains the 3 six items scales Somatization, Depression, Anxiety, and the Global Score (GSI). In a sample of N=638 psychotherapeutic patients, reliability and validity were proven. Reliability of the 3 scales was good: Somatization alpha=0.79, Depression alpha=0.84, Anxiety alpha=0.84, and GSI alpha=0.91. The postulated three-factor structure was proven sufficiently using confirmatory and explorative factor analyses. The questionnaire separated different patients groups. Judgments of the therapists corresponded well with the self-rating behavior of the patients. In conclusion, the psychometric evaluation of the BSI-18 resulted in persuasive evidence for its reliability and validity. The loss of information, as a result of item reduction, is acceptable analyzing large samples; in cases of individual analyses, the SCL-90-R is advised.