Cognitive functioning in first episode bipolar I disorder patients with and without history of psychosis

Social cognition and neurocognition in first-episode bipolar disorder and psychosis: The effect of negative and attenuated positive symptoms

BACKGROUND

Schizophrenia and bipolar disorder are associated with neurocognitive and social-cognitive impairments. To date very few studies investigated social cognition in first-episode bipolar disorder (FEBD). Our main aim was to investigate the differences in social cognition and neurocognition between FEBD and first-episode psychosis (FEP). Another aim was to investigate neurocognitive correlates of negative symptoms and attenuated psychotic symptoms in FEBD.

METHODS

This study included 55 FEBD, 64 FEP and 43 healthy controls. A comprehensive neuropsychological battery assessing social cognition, processing speed, verbal and visual memory, working memory, sustained attention, and executive functions was administered to all participants.

RESULTS

Both FEBD and FEP were associated with widespread deficits in all neurocognitive domains and social cognition. Both FEP (d = -1.19) and FEBP (d = -0.88) were also impaired in social cognition. In FEP, effect sizes (Cohen's d) of neurocognitive deficits ranged from -0.71 to -1.56. FEBD was also associated with relatively milder but similar neurocognitive deficits (d = -0.61 to-1.17). FEBD group performed significantly better than FEP group in verbal and visual memory, processing speed, and executive function domains (d = -0.40 to-0.52). Negative symptoms and social functioning were associated with neuropsychological impairment in both groups. The severity of attenuated psychotic symptoms was associated with poorer verbal memory in FEBD (r = -0.39, p < 0.01).

LIMITATIONS

The cross-sectional nature of the current study is the main limitation.

CONCLUSIONS

Neurocognitive and social-cognitive deficits are evident in both FEBD and FEP. In FEBD, more severe memory deficits might be markers of clinical overlap and shared neurobiological vulnerability with psychotic disorders.

Early Childhood Neurocognition in Relation to Middle Childhood Psychotic Experiences in Children at Familial High Risk of Schizophrenia or Bipolar Disorder and Population-Based Controls: The Danish High Risk and Resilience Study

BACKGROUND AND HYPOTHESIS

Familial high-risk (FHR) studies examining longitudinal associations between neurocognition and psychotic experiences are currently lacking. We hypothesized neurocognitive impairments at age 7 to be associated with increased risk of psychotic experiences from age 7 to 11 in children at familial high risk of schizophrenia (FHR-SZ) or bipolar disorder (FHR-BP) and population-based controls (PBC), and further, impaired functioning in some neurocognitive functions to be associated with greater risk of psychotic experiences in children at FHR-SZ or FHR-BP relative to PBC.

STUDY DESIGN

Neurocognition was assessed at age 7 (early childhood) and psychotic experiences from age 7 to 11 (middle childhood) in 449 children from the Danish High Risk and Resilience Study. The neurocognitive assessment covered intelligence, processing speed, attention, visuospatial and verbal memory, working memory, and set-shifting. Psychotic experiences were assessed through face-to-face interviews with the primary caregiver and the child.

STUDY RESULTS

Set-shifting impairments at age 7 were associated with greater risk of psychotic experiences from age 7 to 11 in children at FHR-SZ. Children at FHR-BP and PBC showed no differential associations. Working memory and visuospatial memory impairments were related to increased risk of psychotic experiences across the cohort. However, adjusting for concurrent psychopathology attenuated these findings.

CONCLUSIONS

Early childhood neurocognitive impairments are risk markers of middle childhood psychotic experiences, of which impaired set-shifting appears to further increase the risk of psychotic experiences in children at FHR-SZ. More research is needed to examine longitudinal associations between neurocognitive impairments and psychotic experiences in FHR samples.

Cognitive reserve may outperform age, mood and psychiatric comorbidities as a predictor of executive functioning in bipolar disorder and healthy adults

INTRODUCTION

Cognitive reserve plays a protective role against executive dysfunction in healthy adults and individuals with psychiatric illnesses such as bipolar disorder. However, the magnitude of the influence of cognitive reserve on specific executive functions (EFs), and its impact relative to variables such as depressive symptoms, age and psychiatric comorbidities, is unexplored. This study aimed to quantify the influence of cognitive reserve on specific EFs, and compare its impact with that of depressive symptoms, age and psychiatric comorbidities, in separate models for patients with bipolar disorder and healthy adults.

METHOD

This was a cross-sectional study of 121 adults with no mood disorders and 109 with bipolar disorder, all of whom underwent a comprehensive psychiatric assessment and evaluation of the EFs. Cognitive reserve was measured using years of education, IQ and reading and writing habits. The association between EFs and predictors (cognitive reserve, depressive symptoms, age and psychiatric comorbidities) was evaluated through structural equation modeling. Four models were constructed for each group independently (bipolar disorder and control), one each for working memory, verbal fluency, inhibition and flexibility, due to group differences in age and cognitive reserve.

RESULTS

Working memory, inhibition and flexibility were most significantly predicted by cognitive reserve and age. Verbal fluency was only predicted by cognitive reserve. Comorbidities and depressive symptoms were not significant in any of the models. Cognitive reserve had a positive influence on all EFs in models for patients with bipolar disorder and models for control participants. Age had a negative impact on three of the four EFs tested.

CONCLUSION

Fostering cognitive reserve through continued education and cognitively stimulating leisure activities may be an effective intervention for executive dysfunction in patients and non-patients alike. In some cases, the effects of these interventions may outweigh the negative cognitive impact of aging, depressive symptoms and psychiatric conditions.

Cognition in offspring of parents with psychotic and non-psychotic severe mental illness

BACKGROUND

Cognitive impairment is a feature of severe mental illness (SMI; schizophrenia, bipolar disorder, major depressive disorder). Psychotic forms of SMI may be associated with greater cognitive impairment, but it is unclear if this differential impairment pre-dates illness onset or whether it reflects a consequence of the disorder. To establish if there is a developmental impairment related to familial risk of psychotic SMI, we investigated cognition in offspring of parents with psychotic and non-psychotic SMI.

METHOD

Participants included 360 children and youth (mean age 11.10, SD 4.03, range 6-24), including 68 offspring of parents with psychotic SMI, 193 offspring of parents with non-psychotic SMI, and 99 offspring of control parents. The cognitive battery assessed a range of functions using standardized tests and executive function tasks from the Cambridge Automated Neuropsychological Test Battery.

RESULTS

Compared to controls, offspring of parents with psychotic SMI performed worse on overall cognition (β = -0.32; p < 0.001) and 6 of 15 cognitive domains, including verbal intelligence, verbal working memory, processing speed, verbal learning and memory, verbal fluency, and sustained attention. Offspring of parents with non-psychotic SMI performed worse than controls on 3 of the 15 domain specific cognitive tests, including verbal intelligence, visual memory and decision-making.

CONCLUSIONS

Widespread mild-to-moderate cognitive impairments are present in young offspring at familial risk for transdiagnostic psychotic SMI. Offspring at familial risk for non-psychotic SMI showed fewer and more specific impairments in the domains of verbal intelligence, visual memory and decision-making.

Neurocognitive functioning during symptomatic states and remission in bipolar disorder and schizophrenia: A comparative study

Aims Patients with bipolar disorder present milder cognitive impairment in comparison to patients with schizophrenia. Psychotic symptoms are associated with poorer cognitive functioning in both disorders. We aim to compare cognitive dysfunction between bipolar disorder and schizophrenia across symptomatic and remitted states. Methods An extensive cognitive battery was used to assess bipolar disorder patients (32 in manic episodes with psychotic features, 44 in euthymia), patients with schizophrenia (41 symptomatic, 39 remitted), and 55 healthy controls. A global cognitive factor and six neurocognitive domain factors were identified using principal component analyses. Results Global cognition components differed according to both illness and remission status; working memory differed according to remission status regardless of diagnosis; verbal fluency differed according to diagnosis regardless of remission status. An omnibus F test revealed that the remission state had a significant impact on processing speed in schizophrenia. Conclusion Our data suggest that both disorders are associated with state dependent (i.e., global cognition and working memory) and diagnosis dependent (i.e., global cognition and verbal fluency) neurocognitive dysfunctions. Processing speed was exclusively influenced by symptomatic states of schizophrenia.

PRIMARY EPISODE OF BIPOLAR AFFECTIVE DISORDER

Background. Bipolar affective disorder (BAD) is a topical issue of contemporary psychiatry. The features of the primary episode (PE) of the disease are extremely important for prognosis, treatment and rehabilitation measures of BAD. Individual psychological features of the patients with PE of BAD are still unexplored that complicates development of new methods of prediction, treatment and prevention of BAD. Objective. The aim of the study was to investigate individual psychological features of the patients with a primary episode of bipolar affective disorder, taking into account the gender factor and clinical variant of the BAD debut. Methods. 153 patients (65 men and 88 women) with a primary episode of bipolar affective disorder were examined. The patients were divided into three groups according to the clinical variant of the course of PE of BAD: depressive variant, manic variant and mixed variant. The examination was carried out using the Standardized multifactor method of personality research (SMMPR). Statistical processing of the data was performed using the non-parametric Mann-Whitney test. Results. The most significant differences in the quantitative indicators of SMMPR were found when comparing depressive and manic, as well as depressive and mixed variants of PE of BAD, and lesser – when comparing manic and mixed variants. Most of all, these differences were expressed in terms of pessimism, impulsiveness, individualism and optimism.  Conclusions. Some peculiar features of male and female patients with depressive, manic and mixed variants of PE of BAD promoting to search for new methods of prediction, treatment and prevention of BAD have been defined.

What specifically contributes to disturbed non-verbal fluency in patients with bipolar disorder: Ineffective performance initiation, slowed processing or lack of the execution strategy?

The study aimed at identifying the cognitive and clinical determinants of impaired design fluency in bipolar patients, with special reference to processing speed and performance strategy. A sample of bipolar disorder patients (BD, n = 45) and matched healthy controls (HC, n = 42) underwent the assessment of figural fluency, cognitive and manual speed, cognitive effort and affective state. An electronic version of design fluency test was applied, enabling assessment of performance speed, execution strategy and spontaneous fluctuations in production efficiency. Additional clinical variables were also controlled. BD patients produced significantly less unique designs, performed slower, utilized less effective strategy, their ability to concentrate designs production in the initial phase of performance was significantly reduced compared with HC. Regression analysis revealed that in BD patients design fluency main outcome was significantly predicted by slowed creation of designs and the number of hospitalizations, while in the HC group, the main fluency result was predicted only by the executive strategy indicators. Our study showed that non-verbal fluency in BD group was determined by essentially different neuropsychological functions than in healthy controls. Obtained findings confirm that cognitive slowdown should be an important goal of cognitive remediation and pharmacological interventions in bipolar disorder.

Neurocognition and functional outcome in patients with psychotic, non-psychotic bipolar I disorder, and schizophrenia. A five-year follow-up

Background:

Bipolar disorder (BD) and schizophrenia (SZ) are characterized by neurocognitive and functional deficits with marked heterogeneity. It has been suggested that BD with a history of psychotic symptoms (BD-P) could constitute a phenotypically homogeneous subtype characterized by greater neurocognitive and functional impairments, or by a distinct trajectory of such deficits. The aim of this study was to compare the neurocognitive and functional course of euthymic BD-P, euthymic BD patients without a history of psychosis (BD-NP), stabilized patients with schizophrenia and healthy subjects, during a five-year follow-up.

Methods:

Neurocognitive and psychosocial function was examined in 100 euthymic patients with BD (50 BD-P, 50 BD-NP), 50 stabilized patients with schizophrenia (SZ), and 51 healthy controls (HC) at baseline (T1), and after a 5-year follow-up (T2).

Results:

The course of both neurocognitive performance and functional outcome of patients with SZ and BD (BD-P and BD-NP) is stable. The profile of neurocognitive impairment of patients with SZ or BD (BD-P and BD-NP), is similar, with only quantitative differences circumscribed to certain domains, such as working memory. The subgroup of patients with BD-NP does not show functional deterioration.

Conclusions:

We have not found evidence of progression in the neurocognitive or psychosocial impairment in any of the three groups of patients, although it cannot be dismissed the possibility of a subset of patients with a progressive course. Other longitudinal studies with larger samples and longer duration are necessary to confirm these findings.

Cognitive Deficits in Psychotic Disorders: A Lifespan Perspective

Individuals with disorders that include psychotic symptoms (i.e. psychotic disorders) experience broad cognitive impairments in the chronic state, indicating a dimension of abnormality associated with the experience of psychosis. These impairments negatively impact functional outcome, contributing to the disabling nature of schizophrenia, bipolar disorder, and psychotic depression. The robust and reliable nature of cognitive deficits has led researchers to explore the timing and profile of impairments, as this may elucidate different neurodevelopmental patterns in individuals who experience psychosis. Here, we review the literature on cognitive deficits across the life span of individuals with psychotic disorder and psychotic-like experiences, highlighting the dimensional nature of both psychosis and cognitive ability. We identify premorbid generalized cognitive impairment in schizophrenia that worsens throughout development, and stabilizes by the first-episode of psychosis, suggesting a neurodevelopmental course. Research in affective psychosis is less clear, with mixed evidence regarding premorbid deficits, but a fairly reliable generalized deficit at first-episode, which appears to worsen into the chronic state. In general, cognitive impairments are most severe in schizophrenia, intermediate in bipolar disorder, and the least severe in psychotic depression. In all groups, cognitive deficits are associated with poorer functional outcome. Finally, while the generalized deficit is the clearest and most reliable signal, data suggests specific deficits in verbal memory across all groups, specific processing speed impairments in schizophrenia and executive functioning impairments in bipolar disorder. Cognitive deficits are a core feature of psychotic disorders that provide a window into understanding developmental course and risk for psychosis.