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

Individualized prediction of multi-domain intelligence quotient in bipolar disorder patients using resting-state functional connectivity

BACKGROUND

Although accumulating studies have explored the neural underpinnings of intelligence quotient (IQ) in patients with bipolar disorder (BD), these studies utilized a classification/comparison scheme that emphasized differences between BD and healthy controls at a group level. The present study aimed to infer BD patients' IQ scores at the individual level using a prediction model.

METHODS

We applied a cross-validated Connectome-based Predictive Modeling (CPM) framework using resting-state fMRI functional connectivity (FCs) to predict BD patients' IQ scores, including verbal IQ (VIQ), performance IQ (PIQ), and full-scale IQ (FSIQ). For each IQ domain, we selected the FCs that contributed to the predictions and described their distribution across eight widely-recognized functional networks. Moreover, we further explored the overlapping patterns of the contributed FCs for different IQ domains.

RESULTS

The CPM achieved statistically significant prediction performance for three IQ domains in BD patients. Regarding the contributed FCs, we observed a widespread distribution of internetwork FCs across somatomotor, visual, dorsal attention, and ventral attention networks, demonstrating their correspondence with aberrant FCs correlated to cognition deficits in BD patients. A convergent pattern in terms of contributed FCs for different IQ domains was observed, as evidenced by the shared-FCs with a leftward hemispheric dominance.

CONCLUSIONS

The present study preliminarily explored the feasibility of inferring individual IQ scores in BD patients using the FCs-based CPM framework. It is a step toward the development of applicable techniques for quantitative and objective cognitive assessment in BD patients and contributes novel insights into understanding the complex neural mechanisms underlying different IQ domains.

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.

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.