Differentiating bipolar disorders from unipolar depression by applying the Brief Assessment of Cognition in Affective Disorders

Cluster analysis exploring the impact of childhood neglect on cognitive function in patients with bipolar disorder

BACKGROUND

Bipolar disorder (BD) is a severe mental disorder related to neurocognitive deficits. Exposure to childhood trauma is associated with worse cognitive performance. Different compositions of childhood trauma in BD and their impacts on cognition are rarely reported.

METHODS

We used the Brief Assessment of Cognition in Affective Disorders (BAC-A) to assess cognitive performance and the Chinese version of the Short Form of the Childhood Trauma Questionnaire (C-CTQ-SF) to assess childhood trauma experience among 55 euthymic BD patients. Cluster analysis was applied to dissect their childhood trauma experiences, which revealed three distinct clusters: a low trauma group, neglect-focus group, and multiple-trauma-experience group. We compared the cognitive function between the three clusters and used a generalized linear model to evaluate the impact of childhood neglect on cognitive domains.

RESULTS

The neglect-focus cluster showed prominent exposures to physical and emotional neglect (41.8%). BD patients in this cluster performed worse in BAC-A compared with patients in the multiple trauma cluster, especially in working memory and processing speed. The neglect-focus group revealed a significant negative effect on the composite score (ß = -0.904, p = 0.025) and working memory (ß = -1.150, p = 0.002) after adjusting sex, age, education year, BMI and total psychotropic defined daily dose.

CONCLUSIONS

Distinct patterns of childhood trauma experience are seen in BD patients and are related with different cognitive profiles. Early exposure of neglect-focus trauma was associated with the worst cognitive performance in current study. Further studies investigating the intensity of the neglect, as well as individual resilience and coping mechanisms in BD, are warranted.

Differences in facial emotion recognition between bipolar disorder and other clinical populations: A systematic review and meta-analysis

Facial emotion (or expression) recognition (FER) is a domain of affective cognition impaired across various psychiatric conditions, including bipolar disorder (BD). We conducted a systematic review and meta-analysis searching for eligible articles published from inception to April 26, 2023, in PubMed/MEDLINE, Scopus, EMBASE, and PsycINFO to examine whether and to what extent FER would differ between people with BD and those with other mental disorders. Thirty-three studies comparing 1506 BD patients with 1973 clinical controls were included in the present systematic review, and twenty-six of them were analyzed in random-effects meta-analyses exploring the discrepancies in discriminating or identifying emotional stimuli at a general and specific level. Individuals with BD were more accurate in identifying each type of emotion during a FER task compared to individuals diagnosed with schizophrenia (SCZ) (SMD = 0.27; p-value = 0.006), with specific differences in the perception of anger (SMD = 0.46; p-value = 1.19e-06), fear (SMD = 0.38; p-value = 8.2e-04), and sadness (SMD = 0.33; p-value = 0.026). In contrast, BD patients were less accurate than individuals with major depressive disorder (MDD) in identifying each type of emotion (SMD = -0.24; p-value = 0.014), but these differences were more specific for sad emotional stimuli (SMD = -0.31; p-value = 0.009). No significant differences were observed when BD was compared with children and adolescents diagnosed with attention-deficit/hyperactivity disorder. FER emerges as a potential integrative instrument for guiding diagnosis by enabling discrimination between BD and SCZ or MDD. Enhancing the standardization of adopted tasks could further enhance the accuracy of this tool, leveraging FER potential as a therapeutic target.

Neuropsychological instruments for bipolar disorders: A systematic review on psychometric properties

BACKGROUND

Cognitive deficits are a core feature of bipolar disorder (BD) that persist during the euthymic phase and affect global functioning. However, nowadays, there is no consensus on the optimal tool to capture cognitive deficits in BD. Therefore, this review aims to examine the psychometric properties of tools commonly used to assess cognitive functioning in BD.

METHODS

Literature search was conducted on PubMed and Web of Science databases on August 1, 2022 and on April 20, 2023, yielding 1758 de-duplicated records. Thirteen studies fulfilled the inclusion criteria and were included in the review.

RESULTS

All tools examined showed acceptable-to-good psychometric properties suggesting that both brief cognitive screeners and comprehensive batteries may be appropriate for detecting or monitoring cognitive changes in BD.

LIMITATIONS

Methodological differences between the included studies precluded a direct comparison of the results. Further research is needed to investigate the psychometric properties of cognitive tools that assess also affective and social cognition.

CONCLUSIONS

The tools examined appear sensitive enough to distinguish between BD patients with versus without cognitive deficits, however, an optimal tool has not yet been identified. The applicability and clinical utility of the tools may depend on multiple factors such as available resources. That said, web-based instruments are expected to become the first-choice instrument for cognitive screening as they can be applied on a large scale and at an affordable cost. As for second-level assessment instruments, the BACA shows robust psychometric properties and tests both affective and non-affective cognition.

Validation of the THINC-It Tool for Assessment of Cognitive Impairment in Patients with Bipolar Depression

BACKGROUND

Cognitive impairment is one of the core features of bipolar depression. A unified, reliable, and valid assessment tool is key to screening and assessing cognitive impairment. The THINC-Integrated Tool (THINC-it) is a simple and quick battery for screening cognitive impairment in patients with major depressive disorder. However, the use of the tool has not been validated in patients with bipolar depression.

METHODS

The cognitive functions of 120 patients with bipolar depression and 100 healthy controls were evaluated using the THINC-it tool including Spotter, Symbol Check, Codebreaker, Trials, and the only one subjective test (PDQ-5-D) and five corresponding standard tests. A psychometric analysis of the THINC-it tool was performed.

RESULTS

The overall Cronbach's alpha coefficient of the THINC-it tool was 0.815. The intra-group correlation coefficient (ICC) of retest reliability ranged from 0.571 to 0.854 (P<0.001), while the correlation r of parallel validity ranged from 0.291 to 0.921 (P<0.001). There were significant differences in the two groups Z-scores of THINC-it total score, Spotter, Codebreaker, Trails, and PDQ-5-D (P<0.05). Construct validity was analyzed using exploratory factor analysis (EFA). The Kaiser-Meyer-Olkin (KMO) value was 0.749. Using Bartlett's Sphericity test, the χ ² (10) value was 198.257 (P<0.001). The factor loading coefficients of Spotter, Symbol Check, Codebreaker, and Trails on the common factor 1 were -0.724, 0.748, 0.824, and -0.717, respectively, and the factor loading coefficient of PDQ-5-D on the common factor 2 was 0.957. Results revealed that the correlation coefficient of the two common factors was 0.125.

CONCLUSION

The THINC-it tool has good reliability and validity in assessing patients with bipolar depression.

The centrality of working memory networks in differentiating bipolar type I depression from unipolar depression: A task-fMRI study

OBJECTIVES

Up to 70%-80% of patients with bipolar disorder are misdiagnosed as having major depressive disorder (MDD), leading to both delayed intervention and worsening disability. Differences in the cognitive neurophysiology may serve to distinguish between the depressive phase of type 1 bipolar disorder (BDD-I) from MDD, though this remains to be demonstrated. To this end, we investigate the discriminatory signal in the topological organization of the functional connectome during a working memory (WM) task in BDD-I and MDD, as a candidate identification approach.

METHODS

We calculated and compared the degree centrality (DC) at the whole-brain voxel-wise level in 31 patients with BDD-I, 35 patients with MDD, and 80 healthy controls (HCs) during an n-back task. We further extracted the distinct DC patterns in the two patient groups under different WM loads and used machine learning approaches to determine the distinguishing ability of the DC map.

RESULTS

Patients with BDD-I had lower accuracy and longer reaction time (RT) than HCs at high WM loads. BDD-I is characterized by decreased DC in the default mode network (DMN) and the sensorimotor network (SMN) when facing high WM load. In contrast, MDD is characterized by increased DC in the DMN during high WM load. Higher WM load resulted in better classification performance, with the distinct aberrant DC maps under 2-back load discriminating the two disorders with 90.91% accuracy.

CONCLUSIONS

The distributed brain connectivity during high WM load provides novel insights into the neurophysiological mechanisms underlying cognitive impairment of depression. This could potentially distinguish BDD-I from MDD if replicated in future large-scale evaluations of first-episode depression with longitudinal confirmation of diagnostic transition.

Processing speed - A potential candidate cognitive endophenotype for bipolar disorder

Background

Bipolar disorder (BD) is a chronic multifactorial disorder that presents with cognitive impairment as one of its main features, in patients as well as in their first-degree relatives. However, the profile of cognitive dysfunction in BD patients and their relatives is not yet well defined. Various neurocognitive deficits have been proposed as endophenotypes for BD. In the present study, we explored the susceptibility to neurocognitive deficits in BD patients and their siblings compared to healthy controls.

Method

A sample consisting of patients diagnosed with BD (N=37), their unaffected siblings (N=30) and a healthy control group (N=39) was assessed using the Brief Assessment of Cognition for Affective Disorders (BAC-A) battery of tests in various cognitive domains: memory, processing speed, working memory, reasoning and problem solving, and affective processing.

Results

Compared to healthy controls, BD patients and their unaffected siblings showed deficits in attention and motor speed, or processing speed as measured by the Symbol coding task (p = 0.008), as well as a similar degree of impairment (p = 1.000).

Limitations

The lack of statistically significant findings in the other cognitive domains could be related to differences in task difficulty. Most patients were taking psychotropic medication with varying effects on cognition and being treated as outpatients, implying a currently higher level of functioning, which may limit extrapolation of the sample to the general population of BD patients.

Conclusions

These results support the view of considering processing speed as an endophenotype for bipolar disorder.

Working memory updating in individuals with bipolar and unipolar depression: fMRI study

Understanding neurobiological characteristics of cognitive dysfunction in distinct psychiatric disorders remains challenging. In this secondary data analysis, we examined neurobiological differences in brain response during working memory updating among individuals with bipolar disorder (BD), those with unipolar depression (UD), and healthy controls (HC). Individuals between 18-45 years of age with BD (n = 100), UD (n = 109), and HC (n = 172) were scanned using fMRI while performing 0-back (easy) and 2-back (difficult) tasks with letters as the stimuli and happy, fearful, or neutral faces as distractors. The 2(n-back) × 3(groups) × 3(distractors) ANCOVA examined reaction time (RT), accuracy, and brain activation during the task. HC showed more accurate and faster responses than individuals with BD and UD. Difficulty-related activation in the prefrontal, posterior parietal, paracingulate cortices, striatal, lateral occipital, precuneus, and thalamic regions differed among groups. Individuals with BD showed significantly lower difficulty-related activation differences in the left lateral occipital and the right paracingulate cortices than those with UD. In individuals with BD, greater difficulty-related worsening in accuracy was associated with smaller activity changes in the right precuneus, while greater difficulty-related slowing in RT was associated with smaller activity changes in the prefrontal, frontal opercular, paracingulate, posterior parietal, and lateral occipital cortices. Measures of current depression and mania did not correlate with the difficulty-related brain activation differences in either group. Our findings suggest that the alterations in the working memory circuitry may be a trait characteristic of reduced working memory capacity in mood disorders. Aberrant patterns of activation in the left lateral occipital and paracingulate cortices may be specific to BD.

A critical overview of tools for assessing cognition in bipolar disorder

Cognitive deficits are prevalent in bipolar disorder even during the euthymic phase, having a negative impact on global functioning and quality of life. As such, more and more mental health professionals agree that neuropsychological assessment should be considered an essential component of the clinical management of bipolar patients. However, no gold standard tool has been established so far. According to bipolar disorder experts targeting cognition, appropriate cognitive tools should be brief, easy to administer, cost-effective and validated in the target population. In this commentary, we critically appraised the strengths and limitations of the tools most commonly used to assess cognitive functioning in bipolar patients, both for screening and diagnostic purposes.

The Italian version of the Brief Assessment of Cognition in Affective Disorders: performance of patients with bipolar disorder and healthy controls

OBJECTIVES

Cognitive deficits in Bipolar Disorder (BD) are significant enough to have an impact on daily functioning. Therefore, appropriate tools must be used to improve our understanding of the nature and severity of cognitive deficits in BD. In this study, we aimed to compare the cognitive profiles of patients with BD and healthy controls (HC) applying the Italian version of the Brief Assessment of Cognition in Affective Disorders (BAC-A).

METHODS

This cross-sectional study included 127 patients with BD and 134 HC. The participants' cognitive profiles were evaluated using the Italian version of the BAC-A, which assesses verbal memory, working memory, motor speed, verbal fluency, attention & processing speed, executive functions, and two new measures of affective processing. The BAC-A raw scores were corrected using the normative data for the Italian population. In addition, we explored whether intelligence quotient (IQ) and specific clinical variables would predict the BAC-A affective, non-affective, and total composite scores of patients with BD and HC.

RESULTS

HC performed better than patients with BD in all BAC-A subtests (all p < .001), except for subtests of the Affective Interference Test. (p ≥ .05). The effect sizes varied in magnitude and ranged between d = 0.02 and d = 1.27. In patients with BD, lower BAC-A composite scores were predicted by a higher number of hospitalizations. There was a significant association between IQ and BAC-A composite scores in both bipolar patients and HC.

CONCLUSIONS

The Italian BAC-A is sensitive to the cognitive impairments of patients with BD in both affective and non-affective cognitive domains.

The Heterogeneity of Longitudinal Cognitive Decline in Euthymic Bipolar I Disorder With Clinical Characteristics and Functional Outcomes

We characterized the heterogeneity and risk factors of cognitive decline in euthymic bipolar disorder (BD), and their magnitude of associations with subjective daily functions. In this retrospective cohort, BD type I patients (N = 128) were followed for an average of 6.5 years. Intelligence quotient (IQ) at index date was recorded, and premorbid IQ was estimated. We used Brief Assessment of Cognition in Affective Disorders (BAC-A) to assess cognition at follow-up. We evaluated current functions with World Health Organization Disability Assessment Schedule 2.0. Clinical and sociodemographic factors were examined for their independent effects on longitudinal cognitive decline. In addition, we employed multivariate adaptive regression spline to detect inflection points for the nature of slope changes in cognitive decline among BD patients. During follow-up years, 21 BD patients (16.4%) showed longitudinal cognitive decline. In cognitive decline group, all cognitive domains of BAC-A were significantly worsened. We found that density of episodes with psychotic features was an independent risk factor for cognitive decline after adjusted for age, gender and dose of mood stabilizer. After the age of 42 years, a steeper cognitive change was observed in the cognitive decline group. The correlation pattern between cognitive domains and functional outcomes differed between patients with and without cognitive decline. The present study characterized cognitive heterogeneity longitudinally in BD patients. As density of episodes play roles for cognitive decline, our results emphasize the importance of relapse prevention. Our findings provide hints for future personalized interventions and facilitating genetic and biological studies for dissecting the heterogeneity of bipolar illness.

Deficiencies in Theory of Mind in patients with schizophrenia, bipolar disorder, and major depressive disorder: A systematic review of secondary literature

Deficiencies in Theory of Mind (ToM) are consistently found in individuals with schizophrenia (SZ), major depressive disorder (MDD), and bipolar disorder (BD). However, the character of these deficits and their role in the pathogenesis of mental illness remains poorly understood. This systematic review synthesizes the available secondary literature pertaining to ToM functioning in individuals with MDD, BD, or SZ, and their respective spectrum disorders in order to delineate disorder or symptom specific patterns of ToM impairment. Literature suggests that ToM deficits increase in severity along the affective-psychotic spectrum, with mild deficits in patients with MDD, and severe deficits in patients with mania or psychosis. Furthermore, ToM deficits appear to be part of a broader developmental phenotype associated with SZ and BD, as suggested by findings of attenuated impairments in ToM in remitted patients with SZ or BD, unaffected first-degree relatives of patients, and clinical high-risk groups. Future psychiatric research on ToM should aim to disentangle relationships between ToM deficits and specific symptom dimensions transdiagnostically, and employ standardized, construct-specific ToM tasks.

Prefrontal cortical activation during working memory task anticipation contributes to discrimination between bipolar and unipolar depression

Distinguishing bipolar disorder (BD) from major depressive disorder (MDD) is clinically challenging, especially during depressive episodes. While both groups are characterized by aberrant working memory and anticipatory processing, the role of these processes in discriminating BD from MDD remains unexplored. In this study, we examine how brain activation corresponding to anticipation of and performance on easy vs. difficult working memory tasks with emotional stimuli contributes to discrimination among BD, MDD, and healthy controls (HC). Depressed individuals with BD (n = 18), MDD (n = 23), and HC (n = 23) were scanned while performing a working memory task in which they had to first anticipate performance on 1-back (easy) or 2-back (difficult) tasks with happy, fearful, or neutral faces, and then, perform the task. Anticipation-related and task-related brain activation was measured in the whole brain using functional magnetic resonance imagining. We used an elastic-net regression for variable selection, and a random forest classifier for BD vs. MDD classification. The former selected the activation differences (1-back minus 2-back) in the lateral and medial prefrontal cortices (PFC) during task anticipation and performance on the working memory tasks with fearful and neutral faces as variables relevant for BD vs. MDD classification. BD vs. MDD were classified with 70.7% accuracy (p < 0.01) based on the neuroimaging measures alone, with 80.5% accuracy (p = 0.001) based on clinical measures alone, and with 85.4% accuracy (p < 0.001) based on clinical and neuroimaging measures together. These findings suggest that PFC activation during working memory task anticipation and performance may be an important biological marker distinguishing BD from MDD.

Investigating the neural basis of cognitive control dysfunction in mood disorders

OBJECTIVES

Dysfunction of cognitive control is a feature of both bipolar disorder (BP) and major depression (MDD) and persists through to remission. However, it is unknown whether these disorders are characterized by common or distinct disruptions of cognitive control function and its neural basis. We investigated this gap in knowledge in asymptomatic BP and MDD participants, interpreted within a framework of normative function.

METHODS

Participants underwent fMRI scans engaging cognitive control through a working memory task and completed a cognitive battery evaluating performance across multiple subdomains of cognitive control, including attention, impulsivity, processing speed, executive function, and memory. Analysis was performed in two stages: (i) cognitive control-related brain activation and deactivation were correlated with cognitive control performance in 115 healthy controls (HCs), then, (ii) significantly correlated regions from (i) were compared between 25 asymptomatic BP, 25 remitted MDD, and with 25 different HCs, matched for age and gender.

RESULTS

Impulsivity and executive function performance were significantly worse in BP compared to both MDD and HCs. Both BP and MDD had significantly poorer memory performance compared to HCs. Greater deactivation of the medial prefrontal cortex (MPFC) during the fMRI task was associated with better executive function in healthy controls. Significantly less deactivation in this region was present in both BP and MDD compared to HCs.

CONCLUSIONS

Failure to deactivate the MPFC, a key region of the default mode network, during working memory processing is a shared neural feature present in both bipolar and major depression and could be a source of common cognitive dysfunction.

Defining cognitive and functional profiles in schizophrenia and affective disorders

BACKGROUND

Neurocognitive dysfunction is a common symptom of various major psychiatric disorders, including schizophrenia, major depressive disorder (MDD), and bipolar I disorder (BD). In this study, we investigated whether cognitive profiles and daily skill functioning could effectively differentiate between patients with schizophrenia, MDD, and BD.

METHOD

In this cross-sectional study, we recruited a total of 63 patients with schizophrenia, 55 patients with MDD, 43 patients with BD, and 92 healthy control subjects. We evaluated participants' cognitive functions and functional capacity using the Brief Assessment of Cognition in Schizophrenia (BACS) and the UCSD Performance-based Skills Assessment, Brief Version (UPSA-B), respectively. Multivariate analysis of covariance was then adopted to determine inter-group differences in BACS and UPSA-B performance.

RESULTS

The BACS was capable of differentiating patients with a major psychiatric disorder (schizophrenia, MDD, and BD) from healthy subjects. Furthermore, schizophrenia patients had poorer motor speed performance than patients with affective disorders. The UPSA-B, particularly the financial portion, was able to distinguish schizophrenia patients from other groups. However, we did not observe any differences in UPSA-B performance between patients with mood disorders and the healthy controls. No significant difference between patients with BD and those with MDD were observed in either cognitive function or in functional capacity. The performances of the BACS and the UPSA-B were positively correlated, particularly in the MDD group.

CONCLUSION

Considering overall performance, the BACS and the UPSA-B characterize different endophenotyping profiles in the aforementioned four participant groups. Therefore, the results support the need for comprehensive assessments that target both cognitive function and functional capacity for patients with major psychiatric disorders.

Defining cognitive profiles of depressive patients using the Brief Assessment of Cognition in Affective Disorders

Background

Cognitive impairments in patients with depressive disorders have a negative impact on their daily skill functioning and quality of life. In this study, we evaluated the cognitive profiles and associated factors of patients with depressive disorders with the Brief Assessment of Cognition in Affective Disorders (BAC-A).

Methods

This cross-sectional study consisted of 75 patients with depressive disorders (56 patients with major depressive disorder (MDD) and 19 patients with depressive disorder NOS or dysthymic disorder (non-MDD)). We evaluated the participants’ cognitive functions at euthymic status using the BAC-A. The BAC-A includes six subtests derived from the Brief Assessment of Cognition in Schizophrenia (BAC-S) and Affective Processing Tests. The current severity of depressive symptoms was assessed with the 17-item Hamilton Depression Rating Scale (HAMD-17), and we recorded any psychotropic drugs being used by the patients.

Results

We observed no differences in cognitive profiles in the MDD group and non-MDD group after adjusting for educational levels, severity of depression, and psychotropic drugs. Instead, the HAMD-17 scores were negatively correlated to cognitive performance in working memory, motor speed, verbal fluency, attention and processing speed, executive function, composite score, and the six indexes of the Affective Processing Test measured by the BAC-A. A longer illness duration was associated with worse performance of four indexes of the Affective Processing Test. Furthermore, benzodiazepine use was associated with a worse performance of verbal memory, and antidepressant use was associated with better motor speed performance.

Conclusion

The current severity of depressive symptoms and psychotropic drugs being taken, not the diagnosis category, are associated with cognitive impairments in patients with depressive disorders. Clinicians should pay particular attention to managing residual depressive symptoms and prescribing adequate psychotropic drugs in order to eliminate depressive patients’ cognitive deficits.

The brief assessment of cognition in affective disorders: Normative data for the Italian population

BACKGROUND

To date there are no validated tests in Italian to assess cognitive functions in Bipolar Disorder. Therefore, this study aimed to provide normative data for the Italian version of the Brief Assessment of Cognition in Affective Disorders (BAC-A), a battery targeting neuro- and affective-cognition in affective disorders.

METHODS

Data were collected from 228 healthy participants (age range: 18-67; mean age: 34.68 ± 12.15 years) across eight recruiting sites. The influence of age, sex and education was measured and adjusted for using multivariate stepwise regression models. Normative values were established by means of the Equivalent Score approach.

RESULTS

Most of the BAC-A subtests showed patterns of association with age (inversely associated with overall cognitive performance), education (positively associated with Verbal Memory and Fluency, Digit Sequencing and Affective Processing subtests) and sex (females performed better than males in the Affective Interference Test but worse in the Emotion Inhibition Task, Digit Sequencing and Tower of London).

LIMITATIONS

The sample size was not sufficiently large for developing stratified norms, using 10-years ranges. Moreover, the participants included in the study were, on average, highly educated.

CONCLUSIONS

The normative data of the BAC-A provided in this study can serve as a cognitive functioning reference for Italian-speaking participants within the age range of the study sample. This can increase the applicability of this test in both clinical and research settings. The reliability and validity of the Italian BAC-A need to be further investigated.

The Chinese version of the Brief Assessment of Cognition in Affective Disorders: normative data of a Mandarin-speaking population

OBJECTIVE

The Brief Assessment of Cognition in Affective Disorders (BAC-A) is administered to assess the cognitive impairments in patients with affective disorders. This study aims to develop the normative data and to explore the factor structure of the Chinese version of the BAC-A in a Mandarin-speaking population.

METHOD

This cross-sectional study consisted of 220 healthy participants (age range: 19-79 years; mean age: 51.5 ± 15.9 years, 48.2% male) in communities in Taiwan. We evaluated all participants with the BAC-A, which is a battery of tests containing verbal memory, working memory, motor speed, verbal fluency, attention & processing speed, and executive function, Affective Interference Test (AIT), Affective Interference Delayed Recognition Test (AIT-DR), and Emotional Inhibition Test (EIT). We categorized the means and standard deviations of all subtests by age group and gender. Principal component analysis (PCA) was used to examine the factor structure of the BAC-A.

RESULTS

Increased age was significantly correlated with reduced performance in all subtests of the BAC-A, except non-affective correct words in the AIT-DR. Compared to females, males exhibited better performance in motor speed, verbal fluency, and executive function, but had worse performance in total non-affective words in the AIT. The results yielded by PCA showed that the indices of the AIT, AIT-DR, and EIT were all correctly categorized, accordingly.

CONCLUSIONS

The normative data of the Chinese BAC-A established in this study can serve as a cognitive function reference for Mandarin-speaking populations. Nevertheless, the reliability and validity of the Chinese BAC-A need to be further verified.