Verbal and Visual Memory Impairments in Bipolar I and II Disorder

Domain-Specific Memory Impairments in Bipolar Mania: Insights from a Tertiary Care Hospital

Background

Cognitive deficits in bipolar affective disorder (BPAD), particularly during manic episodes, are well-documented. However, research on domain-specific memory impairments in bipolar mania is limited, especially in the Indian subcontinent. This study aimed to assess memory impairments in individuals with bipolar disorder using the Postgraduate Institute Memory (PGI-Memory) scale and to highlight domain-specific deficits compared to healthy controls.

Methods

This cross-sectional study was conducted at a tertiary care center in North India. Twenty subjects diagnosed with bipolar mania and 20 age, sex, and education-matched healthy controls between the ages of 18 and 40 were recruited. Memory functions were assessed using the PGI-Memory scale. Mental control and working memory were also evaluated.

Results

Both groups were matched in terms of age, sex, and education. Individuals with bipolar disorder demonstrated significant deficits in various memory domains, including immediate (d = 1.47), recent (d = 0.93), remote (d = 1.58), long-term (d = 2.37), and associative memory (similar pairs: d = 1.4, dissimilar pairs: d = 1.84,), as well as in visual reproduction (d = 2.3) and recognition tasks (d = 1.54). In contrast, their working memory performance was comparable to that of the control group. The largest deficits were observed in long-term memory, visual reproduction, and associative memory.

Conclusions

Bipolar mania is associated with widespread memory impairments, particularly in long-term and associative memory, which may contribute to difficulties in emotional regulation and daily functioning. These findings emphasize the importance of considering memory impairments in the diagnosis and management of BPAD. Further studies are required to investigate the neurobiological foundations of these impairments and to develop specific interventions.

Verbal memory impairments in mood disorders and psychotic disorders: A systematic review of comparative studies

BACKGROUND

Mood and psychotic disorders are both associated with verbal memory impairments. Verbal memory represents an important treatment target for both disorders. However, whether the neurocognitive and neurophysiological profiles of verbal memory impairments differ between specific disorders within these two diagnostic categories and healthy controls remains unclear. The current systematic review synthesized findings from comparative studies which used behavioural and neuroimaging tasks to investigate verbal memory impairments between: (1) mood disorder, psychotic disorder, and healthy control groups; and (2) mood disorder without psychotic features, mood disorder with psychotic features, and healthy control groups.

METHODS

The search strategy combined terms related to three main concepts: 'mood disorders', 'psychotic disorders', and 'verbal memory'. Searches were executed in Embase, MEDLINE, PsycInfo, and PubMed databases. A total of 38 articles met the full eligibility criteria and were included in the final narrative synthesis. Findings were stratified by memory domain (overall composite score, verbal working memory, immediate recall, delayed recall, and recognition memory) and by illness phase (acute and non-acute).

RESULTS

Mood and psychotic disorders displayed consistent verbal memory impairments compared to healthy controls during the acute and non-acute phases. Few significant differences were identified in the literature between mood and psychotic disorders, and between mood disorders with and without psychotic features. Individuals with schizophrenia were found to have decreased immediate and delayed verbal recall performance compared to bipolar disorder groups during the acute phase. Major depressive disorder groups with psychotic features were also found to have decreased delayed verbal recall performance compared to those without psychosis during the acute phase. No consistent differences were identified between mood and psychotic disorders during the non-acute phase. Finally, preliminary evidence suggests there may be functional abnormalities in important frontal and temporal brain regions related to verbal memory difficulties in both mood and psychotic disorders.

DISCUSSION

The current findings have potential implications for the diagnosis and treatment of cognitive impairments in mood and psychotic disorders. Verbal recall memory may serve as a sensitive tool in the risk stratification of cognitive impairments for certain mood and psychotic disorders. Moreover, since no widespread differences between clinical groups were identified, the evidence supports providing targeted interventions for verbal memory, such as pharmacological and non-pharmacological interventions, through a trans-diagnostic approach in mood and psychotic disorders.

Verbal learning, working memory, and attention/vigilance may be candidate phenotypes of bipolar II depression in Chinese Han nationality

OBJECTIVES

Bipolar II depression (BD-II) is a subtype of bipolar disorder with recurrent depressive, manic, and frequent depressive episodes as the main clinical manifestations. This study aimed to compare the cognitive function of patients with BD-II with those of healthy siblings and controls to explore the internal phenotype of BD-II in the field of cognitive function.

METHODS

66 BD-II patients, 58 healthy siblings, and 55 healthy controls were assessed with the Trail Making Test (TMT), Digit Symbol Coding Test (DSCT), Category Fluency, Hopkins Verbal Learning Test-Revised (HVLTR), Brief Visuospatial Memory Test-Revised (BVMT-R), Wechsler Memory Scale 3rd ed. Spatial Span Subtest (WMS-III SS), Neuropsychological Assessment Battery Mazes (NABM), Continuous Performance Test, and Identical Pairs (CPT-IP).

RESULTS

Patients with BD-II showed cognitive deficits in visual learning, reasoning and problem solving, verbal learning, attention/vigilance, working memory, and speed of processing. Healthy siblings showed cognitive deficits in reasoning and problem solving, verbal learning, attention/vigilance, working memory, and speed of processing. Substantial differences were observed among the three groups in reasoning and problem solving.

CONCLUSIONS

Verbal learning, working memory, and attention/vigilance may be potential endophenotypes that can be used to identify BD-II among Han Chinese in the early stage.

Visual memory and psychotic symptoms in youth

BACKGROUND

Psychotic symptoms are common during childhood and adolescence and may indicate transdiagnostic risk of future psychiatric disorders. Lower visual memory ability has been suggested as a potential indicator of future risk of mental illness. The relationship between visual memory and clinician-confirmed definite psychotic symptoms in youth has not yet been explored.

METHODS

We examined visual memory and psychotic symptoms among 205 participants aged 7-27 years in a cohort enriched for parental mood and psychotic disorders. We assessed visual memory using the Rey Complex Figure Test (RCFT) and psychotic symptoms using validated semi-structured interview measures. We tested the relationship between visual memory and psychotic symptoms using mixed-effects logistic regression.

RESULTS

After accounting for age, sex, and family clustering, we found that psychotic symptoms were significantly associated with lower visual memory (OR = 1.80, 95% CI 1.06-3.06, p = 0.030). This result was unchanged after accounting for general cognitive ability.

CONCLUSION

Lower visual memory performance is associated with psychotic symptoms among youth, regardless of general cognitive ability. This finding may inform future targeted early interventions.

A systematic review on neuropsychological function in bipolar disorders type I and II and subthreshold bipolar disorders-something to think about

Neuropsychological dysfunction is a well-established finding in individuals with bipolar disorder type I (BP-I), even during euthymic periods; however, it is less clear whether this also pertains to bipolar disorder type II (BP-II) or those with subthreshold states (SBP; subthreshold bipolar disorder), such as bipolar not otherwise specified (BP-NOS). Herein, we compare the literature regarding neuropsychological performance in BP-II vs BP-I to determine the extent of relative impairment, and we present and review all related studies on cognition in SBP. After systematically searching PubMed, Medline, PsycINFO, and The Cochrane Library, we found 17 papers that comprise all the published studies relevant for this review. The areas that are consistently found to be impaired in BP are executive function, verbal memory, visual spatial working memory, and attention. More studies than not show no significant difference between BP-I and BP-II, particularly in euthymic samples. Preliminary evidence suggests that patients experiencing major depressive episodes who also meet criteria for SBP show similar profiles to BP-II; however, these results pertain only to a depressed sample. SBP were found to perform significantly better than both MDD and healthy controls in a euthymic sample. A consensus on mood state, patient selection, and neuropsychological testing needs to be agreed on for future research. Furthermore, no studies have used the most recent DSM-5 criteria for SBP; future studies should address this. Finally, the underlying bases of cognitive dysfunction in these diagnostic groups need to be further investigated. We suggest recommendations on all of the above current research challenges.

Bipolar disorder and obsessive compulsive disorder: The comorbidity does not further impair the neurocognitive profile

BACKGROUND

The comorbidity of bipolar disorder (BD) and obsessive-compulsive disorder (OCD) has been widely described. Several studies have investigated the cognitive profiles of BD and OCD patients, but studies that compare BD, BD-OCD, and OCD patients in neuropsychological domains do not exist. The purpose of this study was to compare set-shifting, decision making, and central coherence among BD, BD-OCD, and OCD patients.

METHODS

A battery of neuropsychological tests was administered to 68 patients (22 BD, 26 BD-OCD, 20 OCD). The Young Mania Rating Scale and Hamilton Depression Rating Scale were used to evaluate manic and depressive symptoms, and OCD severity was assessed with the Yale Brown Obsessive Compulsive Scale.

RESULTS

No significant differences emerged in decision-making and cognitive flexibility, whereas BD patients had lower scores in the Accuracy Index on Rey-Osterrieth Complex Figure Test and poor response speed on Hayling Sentence Completion Test Part A than OCD patients.

LIMITATIONS

The small sample size with different BD patients, the cross-sectional design, and the study clinical nature.

CONCLUSIONS

The most striking result is that, contrary to our hypothesis, comorbidity does not further impair the neurocognitive profile. The clinical relevance of our work could be a shift from the current cognitive rehabilitation model focusing on individualized pathways towards a new overlapping model for all three patient groups. This could make the cognitive rehabilitation faster and less costly. Notwithstanding, these disorders do not only need cognitive training but also various psycho-educative approaches and treatment according to their different clinical profile.

Verbal Memory Impairment in Patients with Subsyndromal Bipolar Disorder

BACKGROUNDS

Several domains of cognitive function, including learning memory and executive function, are impaired in mood disorders. Also, the relationship between disturbances of these two cognitive domains has been suggested. In line with the recent initiative to establish a standard measure of cognitive decline in bipolar disorder, the present study was conducted to (1) test the criterion-related validity and test-retest reliability of the California Verbal Learning Test (CVLT)-II Japanese version, and (2) determine if type of word learning tasks (i.e., with or without a category structure) affects severity of verbal memory deficits in patients with subsyndromal bipolar disorder.

METHODS

Thirty-six patients with bipolar disorder with mild symptoms and 42 healthy volunteers participated in the study. We first compared effect sizes for memory deficits in patients among the CVLT-II, Brief Assessment of Cognition in Schizophrenia (BACS), and Hopkins Verbal Memory Tests-Revised (HVLT-R). We next evaluated the correlations between scores of the CVLT-II vs. those of the BACS and HVLT-R. Bipolar patients were re-assessed with the same (standard) or alternate forms of the CVLT-II and HVLT-R 1 month later.

RESULTS

Scores on the CVLT-II 1-5 Free Recall and Long-delay Free Recall, as well as the HVLT-R Immediate Recall, but not the BACS List Learning were significantly lower for patients compared to control subjects. The effect sizes for cognitive decline due to the illness were comparable when measured by the CVLT-II and HVLT-R, ranging from 0.5 to 0.6. CVLT-II scores were significantly correlated with those of the HVLT-R and BACS. Test-retest reliability of the CVLT-II was acceptable, and no significant practice effect was observed when the alternate form was used. There was no consistent relationship between mood symptoms and performance on the CVLT-II.

CONCLUSION

These results suggest the CVLT-II Japanese version is able to discriminate between bipolar disorder patients and healthy controls with good sensitivity and validity. Data in this study also indicate that the degree of verbal memory deficits in bipolar disorder may be influenced by memory organizational strategy.

Lifetime Characteristics of Evening-Preference and Irregular Bed-Rise Time Are Associated With Lifetime Seasonal Variation of Mood and Behavior: Comparison Between Individuals With Bipolar Disorder and Healthy Controls

Sleep-wake cycle disruption and seasonal variation in mood and behavior have been associated with mood disorders. This study aimed to investigate the lifetime characteristics of the sleep-wake cycle and its association with the lifetime characteristics of seasonality in individuals with bipolar disorder. Circadian preference, regularity of bed-rise time, and seasonality were evaluated on a lifetime basis using the Composite Scale of Morningness, the Sleep Timing Questionnaire, and the Seasonal Pattern Assessment Questionnaire in clinically stable individuals with bipolar I/II disorders (n = 103/97) and healthy controls (n = 270). Bipolar groups were more likely to have evening preference and irregular bed-rise time. These characteristics were interrelated and, particularly, more prevalent in bipolar II disorder. Seasonality, which was also more prevalent in the bipolar groups, was associated with evening preference and irregularity of the weekday bed-rise time.

The neurocognitive functioning in bipolar disorder: a systematic review of data

BACKGROUND

During the last decades, there have been many different opinions concerning the neurocognitive function in Bipolar disorder (BD). The aim of the current study was to perform a systematic review of the literature and to synthesize the data in a comprehensive picture of the neurocognitive dysfunction in BD.

METHODS

Papers were located with searches in PubMed/MEDLINE, through June 1st 2015. The review followed a modified version of the recommendations of the Preferred Items for Reporting of Systematic Reviews and Meta-Analyses statement.

RESULTS

The initial search returned 110,403 papers. After the deletion of duplicates, 11,771 papers remained for further evaluation. Eventually, 250 were included in the analysis.

CONCLUSION

The current review supports the presence of a neurocognitive deficit in BD, in almost all neurocognitive domains. This deficit is qualitative similar to that observed in schizophrenia but it is less severe. There are no differences between BD subtypes. Its origin is unclear. It seems it is an enduring component and represents a core primary characteristic of the illness, rather than being secondary to the mood state or medication. This core deficit is confounded (either increased or attenuated) by the disease phase, specific personal characteristics of the patients (age, gender, education, etc.), current symptomatology and its treatment (especially psychotic features) and long-term course and long-term exposure to medication, psychiatric and somatic comorbidity and alcohol and/or substance abuse.

Dilemma for enhancing psychiatrists' adherence to guideline (evidence)-based practice

Bipolar disorder (BD) is a prevalent and chronic devastating disorder that is associated with considerable psychosocial and economic morbidity. However, its complexity in the clinical course and manifestation of bipolar disorder is still a significant barrier to accurate differential diagnosis from unipolar depression (UD), by which it is still underdiagnosed and undertreated in clinical practice. In community studies, first onset of BD is usually in the adolescent ages, and the occurrence of UD is usually its first clinical manifestation. In addition, reliable criteria for differentiating UD from BD along with validated treatment guidelines for BD are currently not sufficient or adequate, commonly resulting in misdiagnosis and mismanagement of both clinical conditions. Therefore, the study under evaluation results from clinician practice patterns in the real world will substantially enhance the current understanding on the actual situation and unmet needs for accurate and proper diagnosis and management of bipolar depression.