Metacognitive knowledge and experience across multiple cognitive domains in euthymic bipolar disorder

Decreased dynamic variability of the cerebellum in the euthymic patients with bipolar disorder

BACKGROUND

Bipolar disorder (BD) is a complex mental illness characterized by different mood states, including depression, mania/hypomania, and euthymia. This study aimed to comprehensively evaluate dynamic changes in intrinsic brain activity by using dynamic fractional amplitude of low-frequency fluctuations (dfALFF) and dynamic degree centrality (dDC) in patients with BD euthymia or depression and healthy individuals.

METHODS

The resting-state functional magnetic resonance imaging data were analyzed from 37 euthymic and 28 depressed patients with BD, as well as 85 healthy individuals. Using the sliding-window method, the dfALFF and dDC were calculated for each participant. These values were compared between the 3 groups using one-way analysis of variance (ANOVA). Additional analyses were conducted using different window lengths, step width, and window type to ensure the reliability of the results.

RESULTS

The euthymic group showed significantly lower dfALFF and dDC values of the left and right cerebellum posterior lobe compared with the depressed and control groups (cluster level PFWE < 0.05), while the latter two groups were comparable. Brain regions showing significant group differences in the dfALFF analysis overlapped with those with significant differences in the dDC analysis. These results were consistent across different window lengths, step width, and window type.

CONCLUSIONS

These findings suggested that patients with euthymic BD exhibit less flexibility of temporal functional activities in the cerebellum posterior lobes compared to either depressed patients or healthy individuals. These results could contribute to the development of neuropathological models of BD, ultimately leading to improved diagnosis and treatment of this complex illness.

Do depressed patients really over-report cognitive impairment?

BACKGROUND

Depressed patients report more severe cognitive impairment than is detectable by neuropsychological tests because they may underestimate their cognitive performance. Alternatively, it is possible that cognitive impairment primarily occurs under everyday life conditions as referred to in most questionnaires. The aim of the present study is to investigate the validity of self-reports in patients with major depression in order to better understand the pronounced impairment in self-reports.

METHODS

We investigated 58 patients with major depression and 28 heathy control participants. We administered the "Screen for Cognitive Impairment in Psychiatry" (SCIP) to assess cognitive performance, the "Questionnaire for Cognitive Complaints" (FLei), and the newly developed scale for "Self-Perception of Cognitive Performance in everyday life and test settings" to ask for the self-assessed cognitive performance in everyday life and in a test situation more specifically.

RESULTS

Depressed patients showed an inferior test performance and reported much more general everyday life related cognitive problems compared to healthy participants. When asked more specifically for their cognitive performance in the test-situation compared to others and compared to everyday life, they did not report more test-related and everyday life related impairment than healthy participants did.

LIMITATIONS

Results might be influenced by comorbidity.

CONCLUSIONS

These results have implications for the assessment of subjective cognitive performance of depressed patients and shed light on the negative effects of general versus more specific recall of autobiographical information.

Disrupted network switching in euthymic bipolar disorder: Working memory and self-referential paradigms

BACKGROUND

Patients with bipolar disorder (BD) frequently suffer from neurocognitive deficits that can persist during periods of clinical stability. Specifically, impairments in executive functioning such as working memory and in self-processing have been identified as the main components of the neurocognitive profile observed in euthymic BD patients. The study of the neurobiological correlates of these state-independent alterations may be a prerequisite to develop reliable biomarkers in BD.

METHODS

A sample of 27 euthymic BD patients and 25 healthy participants (HC) completed working memory and self-referential functional Magnetic Resonance Imaging (fMRI) tasks. Activation maps obtained for each group and contrast images (i.e., 2-back > 1-back/self > control) were used for comparisons between patients and HC.

RESULTS

Euthymic BD patients, in comparison to HC, showed a higher ventromedial prefrontal cortex activation during working memory, a result driven by the lack of deactivation in BD patients. In addition, euthymic BD patients displayed a greater dorsomedial and dorsolateral prefrontal cortex activation during self-reference processing.

LIMITATIONS

Pharmacotherapy was described but not included as a confounder in our models. Sample size was modest.

CONCLUSION

Our findings revealed a lack of deactivation in the anterior default mode network (aDMN) during a working memory task, a finding consistent with prior research in BD patients, but also a higher activation in frontal regions within the central executive network (CEN) during self-processing. These results suggest that an imbalance of neural network dynamics underlying external/internal oriented cognition (the CEN and the aDMN, respectively) may be one of the first reliable biomarkers in euthymic bipolar patients.

Revisiting the dynamic comprehensive model of self-awareness: a scoping review and thematic analysis of its impact 20 years later

This study aimed to (1) describe the scope of research related to the Dynamic Comprehensive Model of Awareness (DCMA) (Toglia & Kirk, 2000); (2) identify themes and support for key model postulates; and (3) suggest future research directions related to this model. Using PRISMA scoping guidelines, 366 articles were reviewed, and 54 articles met our inclusion criteria. Selected studies were clustered into three themes: (1) the relationship between general and online self-awareness (50%); (2) interventions based on the model (41%); and (3) factors contributing to self-awareness (9%). Most studies were conducted with participants with acquired brain injury (BI) and traumatic BI (68%), most used a cross-sectional design (50%), and most intervention studies utilized a single-subject design (18%), followed by an experimental design (9%). This review provides evidence for the wide application of the DCMA across varying ages and populations. The need for a multidimensional assessment approach is recognized; however, stronger evidence that supports a uniform assessment of online self-awareness is needed. The intervention studies frequently described the importance of direct experience in developing self-awareness; however, few studies compared how intervention methods to influence general versus online self-awareness, or how cognitive capacity, self-efficacy, psychological factors, and context, influence the development of self-awareness.