Assessment of the German Version of Brief Assessment of Cognition in Schizophrenia (BACS)

Matin Mortazavi; Jakob Amon; Iris Jäger; Genc Hasanaj; Zahra Aminifarsani; Kristin Fischer; Matthias Gamer; CDP Working Group; Alkomiet Hasan; Richard S E Keefe; Gabriele Sachs; Peter Falkai; Daniel Keeser; Florian Raabe; Elias Wagner

doi:10.1016/j.scog.2025.100364

Assessment of the German Version of Brief Assessment of Cognition in Schizophrenia (BACS)

Schizophr Res Cogn. 2025 Apr 30:41:100364. doi: 10.1016/j.scog.2025.100364. eCollection 2025 Sep.

Authors

Matin Mortazavi^{1

2}, Jakob Amon³, Iris Jäger^{1

2}, Genc Hasanaj^{1

2}, Zahra Aminifarsani^{1

2}, Kristin Fischer^{1

2}, Matthias Gamer³; CDP Working Group; Alkomiet Hasan^{1

4}, Richard S E Keefe⁵, Gabriele Sachs⁶, Peter Falkai^{4

7

8}, Daniel Keeser⁷, Florian Raabe^{7

8}, Elias Wagner^{1

2}

Affiliations

¹ Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, University of Augsburg, BKH Augsburg, Augsburg, Germany.
² Evidence-based Psychiatry and Psychotherapy, Faculty of Medicine, University of Augsburg, Augsburg, Germany.
³ Department of Psychology (Experimental Clinical Psychology), University of Würzburg, Würzburg, Germany.
⁴ German Center for Mental Health (DZPG), partner site Munich/Augsburg, Germany.
⁵ Duke University, Durham, NC, USA.
⁶ Medical University of Vienna, 1090 Vienna, Austria.
⁷ Department of Psychiatry and Psychotherapy, LMU University Hospital, LMU Munich, Germany.
⁸ Max Planck Institute of Psychiatry, Munich, Germany.

Abstract

Background: Cognitive impairments are a hallmark of schizophrenia-spectrum disorders (SSD), contributing to poor treatment outcomes and a key treatment target. The Brief Assessment of Cognition in Schizophrenia (BACS) battery is a validated tool designed to evaluate affected core domains in SSD. The present study evaluated psychometric properties of the German version of the BACS in a representative sample of individuals with SSD and healthy control subjects.

Methods: N = 107 individuals with SSD and n = 175 healthy controls were assessed with the German version of the BACS. Diagnosis was confirmed with the Mini International Neuropsychiatric Interview according to DSM-V. Validity was assessed through pair-wise comparisons between SSD individuals and healthy controls and by using receiver operating characteristic analysis. Internal consistency as a measure of reliability was evaluated using McDonald's Omega and Cronbach's Alpha in addition to factor and principal component analysis.

Results: All individuals with SSD exhibited significantly lower z-scores across all BACS subtests and BACS composite scores (Z < -1.5) compared to healthy controls. ROC analysis revealed good diagnostic accuracy with an AUC of 0.83 (95%CI: 0.78,0.88, sensitivity = 0.75, specificity = 0.75). Similar results were observed in sub-cohorts comprising clinically stable SSD patients and those with younger ages (18-35 years old). A unidimensional structure, supported by McDonald's Omega (ω = 0.72) and principal component analysis, confirmed robust internal reliability.

Conclusions: The German BACS demonstrates strong validity and internal reliability when assessed in a representative case-control sample. This study provides an extensive normative dataset for individuals with SSD in German-speaking populations, facilitating future research and clinical assessments of cognition.

Keywords: Cognition; Schizophrenia.