Borderline Symptom List (BSL-23)

Abstract

The Borderline Symptom List (BSL-23) is a concise, 23-item self-report questionnaire developed in 2009 by Bohus and colleagues. It serves as an efficient tool for quantifying the severity of symptoms experienced by individuals diagnosed with Borderline Personality Disorder (BPD). Derived from the comprehensive BSL-95 (2007), the BSL-23 was created specifically to reduce patient burden and increase its utility in routine clinical and research settings. It utilizes a 5-point Likert scale format to assess symptom frequency and intensity over the past week, making it highly sensitive for monitoring therapeutic change over time.

Keywords

Borderline Symptom List, BSL-23, BSL-95, Borderline Personality Disorder, BPD, symptom severity, self-report, psychometrics, treatment monitoring, short scale.

Authors

Martin Bohus, Nicole Kleindienst, Markus F. Limberger, Robert-D. Stieglitz, Martina Domsalla, Alexander L. Chapman, Matthias Wolf.

Purpose

The primary purpose of the BSL-23 is to provide a quick and reliable method for quantifying the current symptom severity associated with Borderline Personality Disorder. Its design addresses the practical limitations of longer instruments, such as the BSL-95, by minimizing the time required for completion while maintaining strong psychometric rigor.

The scale is specifically useful in clinical practice for monitoring treatment effectiveness. Its brevity allows clinicians to administer it weekly, providing frequent, quantifiable data on symptomatic fluctuations. This sensitivity to change makes the BSL-23 an invaluable instrument for tracking patient progress throughout various therapeutic interventions, though it is crucial to note that the BSL-23 is a measure of severity and monitoring, not a diagnostic tool for BPD itself.

Construct

The BSL-23 measures the multifaceted psychological construct of symptomatic severity in individuals with Borderline Personality Disorder. This construct encompasses the distress and dysfunction experienced across various domains characteristic of BPD, including emotional dysregulation, interpersonal difficulties, cognitive distortions, impulsivity, and self-harm tendencies.

As a brief form derived from the BSL-95, the 23 items selected represent the core elements of the broader BPD symptom profile, allowing for a comprehensive yet efficient assessment. The construct is designed to capture the intensity of symptoms experienced over a very recent period (the past week), emphasizing the fluctuating and intensive nature of the disorder.

Validity

The validity of the BSL-23 is strongly supported by its high correspondence with the original, longer instrument, the BSL-95, which itself possesses robust psychometric properties. Research by Bohus et al. (2009) demonstrated an exceptionally high correlation between the scores derived from the BSL-23 and the BSL-95 across various tested samples, ranging from 0.958 to 0.963. This high convergence supports the concurrent validity of the abbreviated scale, confirming that the BSL-23 captures the same underlying symptomatic severity as the original 95-item version.

Furthermore, the BSL-23 has demonstrated strong cross-cultural validity. Although originally developed in German, its translations into multiple languages—including French and Spanish—have undergone rigorous validation, ensuring that the scale’s measurement properties remain reliable and valid across different linguistic and cultural populations (Nicastro et al., 2016; Soler et al., 2013).

Reliability

The reliability of the BSL-23 is characterized by high internal consistency, indicating that the 23 items measure a unified underlying construct of BPD symptom severity. The initial validation study reported high internal consistency, with Cronbach’s α values ranging between 0.935 and 0.969.

These reliability coefficients are comparable to those found for the much longer BSL-95, confirming that the reduction in item count did not lead to a significant loss of reliability. This strong internal consistency supports the use of the BSL-23 as a dependable measure for tracking subtle changes in symptom severity, which is essential for evaluating the effectiveness of ongoing psychological or pharmacological treatments.

Factor Analysis

Although the source material does not provide explicit details on the specific factor structure of the BSL-23, its derivation from the BSL-95 implies a structure designed to reflect the core domains of Borderline Personality Disorder. The maintenance of exceptionally high correlations (0.958–0.963) between the BSL-23 and BSL-95 suggests that the shorter version effectively retained the essential factor weightings and components of the original, multi-dimensional scale.

The selection of the 23 items was driven by the goal of maximizing efficiency while preserving the comprehensive coverage of BPD symptoms, thereby ensuring that the scale remains unidimensional enough for a total severity score while still reflecting the underlying complexity captured by the longer instrument. Subsequent validation studies in various languages have consistently confirmed the robust psychometric properties, reinforcing the stability and appropriateness of the scale’s underlying structure.

Instrument

Test Type: Symptom Severity Self-Report Questionnaire

Format: 23 items utilizing a 5-point Likert scale, ranging from 0 (‘not at all’) to 4 (‘very strong’).

Language Available: Originally German. Validated translations include English, French, Spanish, and others.

Population Group: Clinical population (patients diagnosed with Borderline Personality Disorder).

Age Group: Typically adult populations, though applicable to any age group receiving a BPD diagnosis.

Population Details: The original BSL-95 was developed based on a sample of 379 borderline patients. The BSL-23 is intended for routine use with individuals currently undergoing treatment for BPD.

Test Methodology: Patients evaluate their symptoms for the past week. Scoring involves summing the values of the 23 items. Comparability with the BSL-95 requires comparing the mean values of the scales. A minimum of 90% of the questionnaire must be completed for the scores to be evaluated. The supplement for assessing dysfunctional behavior is scored separately by summation.

Keywords

BSL-23, psychological assessment, clinical monitoring, severity index, emotional dysregulation, behavioral assessment, German scale, short form, Cronbach’s alpha, BPD treatment.

Authors

Author ORCID Identifier: Not provided in source content.

Affiliation Email addresses: Not provided in source content.

Correspondence Address: Not provided in source content.

Permissions & Fee and Test Year

The BSL-23 was developed and initially published in 2009. Information regarding specific licensing fees or permissions required for clinical or research use is not detailed in the provided source content. Users should consult the primary authors (Bohus et al.) or the publishing institutions for official usage guidelines and costs.

Detailed analysis and scoring information for the BSL-23 can be found in the original documentation. The original PDF for scoring analysis is available here: https://www.zi-mannheim.de/fileadmin/user_upload/downloads/forschung/PSM_downloads/BSL_23_english_scoring_06_2007.pdf

Reference’s

• Bohus, M., Kleindienst, N., Limberger, M. F., Stieglitz, R.-d., Domsalla, M., Chapman, A. L., . . . 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.

• Bohus, M., Limberger, M. F., Frank, U., Chapman, A. L., Kühler, T., & Stieglitz, R.-D. (2007). Psychometric Properties of the Borderline Symptom List (BSL). Psychopathology, 40(2), 126-132.

• Mannheim, P. Z. (2007). Borderline Symptom List 23 (BSL-23) Analysis Information Retrieved from https://www.zi-mannheim.de/fileadmin/user_upload/downloads/forschung/PSM_downloads/BSL_23_english_scoring_06_2007.pdf

• Nicastro, R., Prada, P., Kung, A.-L., Salamin, V., Dayer, A., Aubry, J.-M., . . . Perroud, N. (2016). Psychometric properties of the French borderline symptom list, short form (BSL-23). Borderline Personality Disorder and Emotion Dysregulation, 3(1), 4. doi:10.1186/s40479-016-0038-0

• Soler, J., Vega, D., Feliu-Soler, A., Trujols, J., Soto, Á., Elices, M., . . . Pascual, J. C. (2013). Validation of the Spanish version of the borderline symptom list, short form (BSL-23). BMC Psychiatry, 13(1), 1317. doi:10.1186/1471-244X-13-139

Items of the Borderline Symptom List (BSL-23)

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

The specific 23 items comprising the Borderline Symptom List (BSL-23) were not provided in the source content. The scale items are proprietary and typically require permission for full reproduction.