Introduction
Borderline Symptom List (BSL-23) was developed by Martin Bohus and others in 2009 within the domain of psychiatry. Associated with the Central Institute of Mental Health, this 23-item self-report instrument is designed to quantify borderline-typical symptomatology and assess the overall severity of Borderline Personality Disorder (BPD) symptoms. Widely recognized for reducing patient burden while maintaining strong psychometric properties, the questionnaire has been cited over 1000 times in academic literature.
This article provides a comprehensive guide to the BSL-23, detailing its target demographics, scoring methodology, psychometric reliability, and overall utility in clinical research settings.
Key features of the Borderline Symptom List (BSL-23)
Purpose and Use
The BSL-23 is a self-report instrument explicitly developed to quantify borderline-typical symptomatology and assess the overall severity of Borderline Personality Disorder (BPD) symptoms. Specifically, researchers designed it to significantly reduce patient burden and assessment time compared to the full-length version. Furthermore, the tool successfully retains good psychometric properties and sensitivity to therapeutic change. Consequently, it demonstrates a robust ability to discriminate BPD patients from other psychiatric groups across clinical and research settings. Therefore, it serves as a highly effective monitoring tool rather than a diagnostic instrument.
Target Population
Researchers have validated the tool across a wide demographic. Importantly, normative data from validation studies primarily covers individuals aged 18 to 55. Specifically, the core target population includes:
Young Adults (18-24 years)Middle-Aged Adults (25-44 years)Older Adults (45-64 years)Additionally, the questionnaire's target population also includes college and university students, as well as parents in a separate demographic category.
Structure
The BSL-23 is structurally designed to capture a comprehensive range of subjective complaints and clinical impairments typical of Borderline Personality Disorder. Specifically, the 23 items are categorized to reflect four primary domains of BPD symptomatology: affective, cognitive, interpersonal, and impulse-control difficulties. To achieve this, the questionnaire covers an extensive array of specific symptoms, including:
Cognitive and Perceptual Disturbances: Difficulty concentrating, absent-mindedness, frightening images, auditory disturbances, and depersonalization.Affective Instability and Internal Distress: Rapid mood cycling, inner tension, helplessness, loneliness, and feelings of senselessness or worthlessness.Interpersonal Vulnerability: Distrust, vulnerability to criticism, and general vulnerability.Impulsivity and Self-Directed Negativity: Thoughts of self-harm, fascination with death, fear of losing control, self-hatred, self-punishment, shame, disgust, and self-disgust.Scoring Method
Patients rate each of the 23 items on a 5-point Likert scale referring to their experiences over the past week. The response options range from 0 ("not at all") to 4 ("very strong"). To calculate the total score, administrators divide the sum of all item scores by the number of valid items. Consequently, this yields a total score ranging from 0.0 to 4.0, with no reported cut-off values. Higher scores indicate a greater severity of borderline symptomatology. Additionally, researchers can administer a visual analog scale (0–100) alongside the main questionnaire to gauge global well-being, though this does not factor into the primary score. Furthermore, the BSL-23 requires no reverse scoring.
Administration Format
Healthcare professionals typically administer the BSL-23 in just 10 to 15 minutes. Because it requires no specialized training, patients can easily self-administer the assessment. Available administration formats include:
Paper-based formsDigital (Online) platformsIn-person interviewsPhone/Video CallApplication of the Borderline Symptom List (BSL-23)
The BSL-23 functions strictly as a severity-assessment tool for evaluating known BPD patients, rather than serving as a screening or diagnostic instrument. Consequently, its primary applications include:
Monitoring: Clinicians use it to track symptom severity and evaluate a patient's sensitivity to therapeutic change over time.Research: Investigators apply it in studies to reliably quantify BPD symptoms and evaluate overall treatment outcomes.Languages and availability
The BSL-23 offers broad linguistic accessibility across multiple validated language versions. Specifically, these include:
EnglishMandarin ChineseSpanishFrenchGermanBrazilian PortugueseRegarding its availability, the BSL-23 is completely free to use, which greatly enhances its accessibility for both researchers and healthcare providers. However, users must note that the instrument strictly operates under a proprietary license.
Reliability and Validity
Statistical validation confirms the BSL-23 as highly reliable. It boasts a strong Cronbach’s alpha ranging from 0.94 to 0.97 across various samples. Moreover, it exhibits excellent test-retest reliability over one week (r = 0.82).
The instrument demonstrates solid convergent validity through moderate-to-high correlations with the Beck Depression Inventory (r = 0.83) and the SCL-90-R GSI (r = 0.48). Furthermore, it shows a strong negative correlation with the Global Well-Being Visual Analog Scale (r = -0.47 to -0.69). Discriminant validity analysis reveals a large effect size (d = 1.13) when differentiating BPD patients from those with Axis I disorders. Finally, the BSL-23 captures sensitivity to change, with a noticeable effect size (d = 0.47) after three months of dialectical behavior therapy.
Original German Validation Study (First Version). linkOriginal English Validation Study (Most Commonly Used). linkValidation of Spanish Version. linkLimitations and Considerations
However, despite its strengths, the BSL-23 has a few limitations:
Self-report measure: Respondents may be influenced by personal interpretation or memory recall.Cultural Bias: Interpretation outside the original German-speaking population requires cautious application, especially if used without localized validation.Other Versions And Related Questionnaires
Researchers looking for a more exhaustive assessment can utilize the BSL-95, which serves as the full-length version of this questionnaire. Furthermore, professionals frequently cross-reference the BSL-23 with related psychiatric instruments. These complementary tools include:
SCL-90-RBeck Depression Inventory (BDI)ZAN-BPDBorderline Disorder Severity IndexQuestionnaire of Thoughts and FeelingsPersonality Belief QuestionnairePersonality Disorder Beliefs QuestionnaireAdditional Resources
Original German Validation Study (First Version). linkOriginal English Validation Study (Most Commonly Used). linkFor further information or inquiries regarding this questionnaire, please contact Martin Bohus, Department of Psychosomatics and Psychotherapy at the Central Institute of Mental Health in Mannheim, Germany, via his official page. linkFrequently Asked Questions (FAQ)
1. Who can use the BSL-23?
Clinicians, researchers, and healthcare providers use the BSL-23 for patients—including young adults, middle-aged adults, older adults, students, and parents—to evaluate BPD symptom severity.
2. How long does it take to complete the BSL-23?
Patients typically take 10 to 15 minutes to complete the BSL-23, which makes it highly feasible for use in fast-paced clinical and research settings.
3. How is the BSL-23 administered?
Healthcare teams can administer the questionnaire via paper-based forms, digital interfaces, in-person interviews, or phone/video calls—offering maximum flexibility in usage.
4. Is there any cost to using the BSL-23?
The BSL-23 is free to use, though it operates under a proprietary license.
A Word from ResRef about the Borderline Symptom List (BSL-23)
The BSL-23 is a concise and efficient self-report tool for assessing borderline-typical symptomatology and overall BPD severity in both clinical and research settings. It demonstrated excellent internal consistency, good test-retest reliability, and clear sensitivity to therapeutic change in the original development study. The scale provides a single global severity score. Interpretation outside the original German-speaking population or without further validation should be undertaken cautiously, although subsequent translation studies have largely replicated its psychometric properties.
References
Yang H, Lei X, Zhong M, Zhou Q, Ling Y, Jungkunz M and Yi J (2018) Psychometric Properties of the Chinese Version of the Brief Borderline Symptom List in Undergraduate Students and Clinical Patients. Front. Psychol. 9:605. linkSoler, J., Vega, D., Feliu-Soler, A. et al. Validation of the Spanish version of the borderline symptom list, short form (BSL-23). BMC Psychiatry 13, 1317 (2013). linkNicastro, R., Prada, P., Kung, AL. et al. Psychometric properties of the French borderline symptom list, short form (BSL-23). bord personal disord emot dysregul 3, 4 (2016). linkWolf, M., Limberger, M. F., Kleindienst, N., Stieglitz, R. D., Domsalla, M., Philipsen, A., Steil, R., & Bohus, M. (2009). Kurzversion der Borderline-Symptom-Liste (BSL-23): Entwicklung und Uberprüfung der psychometrischen Eigenschaften [Short version of the borderline symptom list (BSL-23): development and psychometric evaluation]. Psychotherapie, Psychosomatik, medizinische Psychologie, 59(8), 321–324. linkCatelan, R. F., Bastos, V. B., Dornelles, V. G., Kleindienst, N., Mocarz-Kleindienst, M., Nardi, A. E., & Pires, P. P. (2026). Psychometric Properties of the Borderline Symptom List 23 for Brazilian Portuguese in a Nonclinical Sample. The primary care companion for CNS disorders, 28(4), 26m04184. linkBohus, M., Kleindienst, N., Limberger, M. F., Stieglitz, R. D., Domsalla, M., Chapman, A. L., Steil, R., Philipsen, A., & Wolf, M. (2009). The short version of the Borderline Symptom List (BSL-23): development and initial data on psychometric properties. Psychopathology, 42(1), 32–39. link