Could schizoaffective disorder, schizophrenia and bipolar I disorder be distinguishable using cognitive profiles?

A Systematic Review of Misdiagnosis of Pediatric Bipolar Disorder: Assessments and Recommendations

Bipolar disorders (BP) are a class of psychiatric disorders with a complex symptom presentation. This systematic review aims to summarize literature pertaining to the misdiagnosis of pediatric BP using the DSM-IV and DSM-5 criteria, while emphasizing the negative impact that untreated BP has on life outcomes. This paper also attempts to outline and summarize available recommendations which may aid in improving diagnostic accuracy of pediatric BP. Scholars Portal Journals, PsychINFO, and MEDLINE databases were used to search articles until March 21, 2023. Inclusion criteria limited this review to articles published between 1995 and 2022 using a pediatric (age < 18) sample. Exclusion criteria omitted articles containing samples with self-reported diagnoses. A total of 15 articles are included in this review; study results were synthesized using a narrative summary. Youth with BP are most frequently misdiagnosed with attention-deficit hyperactive disorder (ADHD), schizophrenia, and major depressive disorder (MDD). Misdiagnosis can lead to inappropriate intervention plans and a delay in proper treatment, negatively impacting a child's quality of life by contributing to social, occupational, and economic adversity. Finally, this review addresses the need for future quantitative research on the implications of false negative diagnoses of pediatric BP.

The role of semantic clustering in the relationship between verbal memory and psychosocial functioning in schizophrenia and bipolar disorder: Possible distinct cognitive pathway compared to healthy controls

BACKGROUND

Verbal memory (VM) is impaired in schizophrenia (SZ) and bipolar disorder (BD), and predicts psychosocial functioning. However, there is a lack of research exploring the role of VM component processes, including semantic clustering, in these disorders. Semantic clustering might impact this association, as effective semantic memory strategies may reflect unimpaired executive control, leading to an adequate functioning. We aimed to investigate VM components in SZ and BD, and the role of semantic clustering in the relationship between VM and functioning.

METHODS

We included 495 participants (156 SZ, 172 BD, and 167 healthy controls (HC)) that underwent an assessment using the Hopkins Verbal Learning Test - Revised for VM and the Functioning Assessment Short Test for psychosocial functioning. We compared groups through ANOVAs and investigated the effect of semantic clustering in the relationship between VM total immediate free recall and functioning through linear regression models.

RESULTS

SZ had worse overall VM performance compared to BD, which performed worse than HCs. HCs used more semantic clustering than SZ and BD, but there were no differences between the two clinical groups. In HCs, semantic clustering impacted the relationship between VM performance and functioning, while no interaction was observed in SZ or BD.

LIMITATIONS

Cross-sectional design; no medication effects or other cognitive functions were assessed.

CONCLUSIONS

SZ and BD may use an alternative cognitive pathway in which the relationship between VM and functioning is independent of complex cognitive processes such as semantic clustering, supporting the cognitive remediation targeting of VM in these disorders.

Neuropsychological aspects of bipolar disorder

Bipolar disorder (BD) is a chronic condition with serious consequences on the health and functionality of patients who suffer from it, with a high heritability and segregation, and aprevalence of between 1% and 2%. Neuropsychological deficits have been implicated as a very important issue related to BD prognosis, so a review was conducted of these deficits, the related factors and their functional consequences. It has been determined that the presence of neuropsychological deficits can vary in patients with BD according to their mood state, with a great influence of depressive symptoms on the cognitive variability of patients with respect to the general population and differences with respect to patients in the manic phase. In euthymic patients, the most affected cognitive domains are those of memory, attention, and executive function, associated with a more severe disease, sociodemographic vulnerability factors, and stable over time. A relationship has been found between poor cognitive performance, especially executive dysfunction, and objective functional deficit. Furthermore, cognitive differences have been outlined between BD and other serious mental illnesses that are described in this review.

A neuropsychological study on Leonhard's nosological system

Phenotype validation of endogenous psychosis is a problem that remains to be solved. This study investigated the neuropsychological performance of endogenous psychosis subtypes according to Wernicke-Kleist-Leonhard's classification system (WKL). The participants included consecutive admissions of patients with schizophrenia spectrum disorder or mood disorder with psychotic symptoms (N = 98) and healthy comparison subjects (N = 50). The patients were assessed by means of semi-structured interviews and diagnosed through the WKL system into three groups: a manic-depressive illness and cycloid psychosis group (MDC), unsystematic schizophrenia (USch) and systematic schizophrenia (SSch). All the participants completed a comprehensive neuropsychological battery. The three Leonhard's psychosis subtypes showed a common neuropsychological profile with differences in the severity of impairment relative to healthy controls. MDC patients showed better performance on premorbid intelligence, verbal memory and global cognitive index than USch and SSch patients, and they showed better performance on processing speed, and working memory than SSch patients. USch patients outperformed SSch patients in verbal memory, working memory and global cognitive index. Neuropsychological performance showed a modest accuracy for classification into the WKL nosology. Our results suggest the existence of a common profile of cognitive impairment cutting across WKL subtypes of endogenous psychosis but with significant differences on a severity continuum. In addition, classification accuracy in the three WKL subtypes by means of neuropsychological performance was modest, ranging between 40 and 64% of correctly classified patients.

Graph Analysis of Verbal Fluency Tests in Schizophrenia and Bipolar Disorder

Verbal Fluency Tests (VFT) are one of the most common neuropsychological tasks used in bipolar disorder (BD) and schizophrenia (SZ) research. Recently, a new VFT analysis method based on graph theory was developed. Interpreting spoken words as nodes and every temporal connection between consecutive words as edges, researchers created graph structures, allowing the extraction of more data from participants’ speech, called Speech Graph Attributes (SGA). The aim of our study was to compare speech graphs, derived from Phonemic and Semantic VFT, between SZ, BD, and healthy controls (HC). Twenty-nine SZ patients, twenty-nine BD patients, and twenty-nine HC performed Semantic and Phonemic VFT. Standard measures (SM) and 13 SGA were analyzed. SZ patients’ Semantic VFT graphs showed lower total word count and correct responses. Their graphs presented less nodes and edges, higher density, smaller diameter, average shortest path (ASP), and largest strongly connected component than the HC group. SM did not differentiate BD and HC groups, and patients’ Semantic VFT graphs presented smaller diameter and ASP than HC. None of the parameters differentiated BD and SZ patients. Our results encourage the use of speech graph analysis, as it reveals verbal fluency alterations that remained unnoticed in the routine comparisons of groups with the use SM.

An examination of neurocognition and theory of mind as predictors of engagement with a tailored digital therapeutic in persons with serious mental illness

There is an increasing interest in the development and implementation of digital therapeutics (apps) in individuals with serious mental illness (SMI). However, there is limited understanding of the role of neurocognition and social cognition on engagement with apps. The present study is a secondary analysis of a pilot randomized controlled trial (N = 62) comparing a tailored digital intervention to treat tobacco use disorder in individuals with SMI to a standard of care digital intervention for the general population. The purpose of this study was to examine the impact of neurocognition, social cognition, and clinical characteristics on indices of app engagement in users of the tailored app compared to users of the standard of care app. Correlational analyses demonstrated that individuals with low levels of neurocognition and social cognition engaged more often and for longer duration with the tailored app compared to the standard of care app. In a series of multilevel zero-inflated negative binomial models, assignment to the tailored app remained the most robust predictor of app interactions (Risk Ratio [RR] = 1.72; p < .01), duration of app use (RR = 6.47; p < .01), and average length of interaction (RR = 2.70; p < .01), after adjusting for key demographic and clinical characteristics, and two measures of cognition. This is one of the first studies to demonstrate that digital therapeutics can be designed to mitigate the impact of neurocognition and social cognition on device engagement in SMI populations. Recommendations are made to advance the use of new analytic models to uncover patterns of engagement with digital therapeutics.

Neurocognition in Bipolar and Depressive Schizoaffective Disorder: A Comparison with Schizophrenia

INTRODUCTION

Schizoaffective disorder (SA) is classified into bipolar (bSA) and depressive (dSA) subtypes. Although clinical differences between both have been reported, there is no clear information regarding their specific cognitive profile.

OBJECTIVE

To compare neurocognition between SA subtypes and schizophrenia (SC).

METHODS

A total of 61 patients were assessed and divided into 3 groups: 35 SC, 16 bSA, and 10 dSA. All participants signed an informed consent letter. The MATRICS Consensus Cognitive Battery, Central and South American version was used to assess neurocognition. The study was performed at the Instituto Nacional de Psiquiatría "Ramón de la Fuente". Participants were identified by specialized psychiatrists. Trained neuropsychologists carried out the clinical and cognitive assessment, which lasted 2 h approximately.

RESULTS

The cognitive assessment showed a significant difference in Trail Making Test part A subtest (F[2,58] = 4.043; p = 0.023]. Post hoc analyses indicated that dSA obtained a significantly higher score than SC (MD = -11.523; p = 0.018). The f test showed a large effect size (f = 0.401). No statistical differences were observed regarding other cognitive variables.

CONCLUSIONS

The cognitive profile of SA subtypes and SC is similar since no differences were found in most subtests. However, dSA may be less impaired than SC in measures of processing speed. Further research with larger samples must be conducted.

Neuropsychological Aspects of Bipolar Disorder

Bipolar disorder (BD) is a chronic condition with serious consequences on the health and functionality of patients who suffer from it, with a high heritability and segregation, and a prevalence of between 1% and 2%. Neuropsychological deficits have been implicated as a very important issue related to BD prognosis, so a review was conducted of these deficits, the related factors and their functional consequences. It has been determined that the presence of neuropsychological deficits can vary in patients with BD according to their mood state, with a great influence of depressive symptoms on the cognitive variability of patients with respect to the general population and differences with respect to patients in the manic phase. In euthymic patients, the most affected cognitive domains are those of memory, attention, and executive function, associated with a more severe disease, sociodemographic vulnerability factors, and stable over time. A relationship has been found between poor cognitive performance, especially executive dysfunction, and objective functional deficit. Furthermore, cognitive differences have been outlined between BD and other serious mental illnesses that are described in the review.

Different facial recognition patterns in schizophrenia and bipolar disorder assessed using a computerized emotional perception test and fMRI

BACKGROUND

The emotional perception test is considered an effective tool in differentiating between schizophrenia and bipolar disorder. We hypothesized that schizophrenic patients would show decreased emotional perception ability compared with bipolar patients and that the disrupted emotional perception ability would be associated with the disrupted functional connectivity within the fronto-temporal-occipital circuit.

METHODS

In total, 55 schizophrenic patients, 54 bipolar patients, and 50 healthy participants were evaluated using a computerized assessment tool for facial emotion recognition, resting-state magnetic resonance imaging, and Korean versions of the Positive and Negative Syndrome Scale (PANSS) and Young Mania Rating Scale (YMRS).

RESULTS

The emotional perception index (EPI) was higher in the schizophrenia group than in the bipolar and healthy control (lowest) groups. The PANSS total and YMRS scores positively correlated with the EPI in schizophrenia and bipolar patients. In healthy controls, EPI positively correlated with regional homogeneity (ReHo) within the left fusiform gyrus, left superior frontal gyrus, left inferior frontal gyrus, and right inferior temporal gyrus. In schizophrenic patients, EPI negatively correlated with ReHo within the frontal lobe and left fusiform gyrus. In bipolar patients, EPI positively correlated with ReHo within the left parietal lobe and negatively correlated with ReHo within both frontal lobes.

LIMITATIONS

More specific definition of EPI should be suggested. Due to lack of cognitive function tests, cognitive functions might be biased throughout the analyses.

CONCLUSIONS

Schizophrenic patients showed decreased emotion recognition abilities compared with bipolar patients. Further, schizophrenic patients showed less frontal cortex usage, while bipolar patients used the parietal lobe to compensate for facial emotion recognition.

Distinct Associations of Cognitive Impairments and Reduced Gray Matter Volumes in Remitted Patients with Schizophrenia and Bipolar Disorder

Background

Cognitive impairments are documented in schizophrenia (SZ) and bipolar disorder (BD) and may be related to gray matter volumes (GMVs). Thus, this study is aimed at exploring whether the association between cognitive impairments and GMV alterations is similar in patients with SZ and BD and understanding the underlying neurobiological mechanisms.

Methods

A total of 137 adult subjects (46 with SZ, 35 with BD, and 56 age-, sex-, and education-matched healthy controls (HC)) completed the MATRICS Consensus Cognitive Battery (MCCB) and structural magnetic resonance imaging scanning. We performed group comparisons of the cognitive impairments, the GMV alterations, and the association between them.

Results

Compared with HC, the patients with SZ and BD showed shared deficits in 4 cognitive domains (i.e., processing speed, working memory, problem solving, and social cognition) and the composite. SZ and BD had commonly decreased GMVs, mainly in the insula, superior temporal pole, amygdala, anterior cingulate, and frontal cortices (superior, middle, opercular inferior, and orbital frontal gyrus). No correlation between MCCB scores and GMVs was detected in SZ. However, for BD, working memory was relevant to the right hemisphere (i.e., right insula, amygdala, superior temporal pole, and medial and dorsolateral superior frontal gyrus). Limitations. The major limitations were that not all patients were the first-episode status and no medication.

Conclusions

The association was mainly limited to the BD group. Thus, the underlying pathophysiology of the cognitive deficits, in terms of GMV alterations, may be diverse between two disorders.

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.

Distinguishing prodromal stage of bipolar disorder and early onset schizophrenia spectrum disorders during adolescence

Prodromal symptoms of bipolar disorder (BD) and early onset schizophrenia spectrum disorder (EOSSD) overlap. To date, there has been no study directly comparing the prodromal stage of both disorders. Thus, the current study is aimed at determining which prodromal symptom clusters differentiate BD and EOSSD. One hundred twenty one adolescents (33 BD-1, 30 EOSSD, 58 healthy controls) were evaluated for the presence of 79 prodromal symptoms, divided into 7 prodromal symptom clusters. Great than 2 subsyndromal manic symptoms and ADHD comorbidity were significantly more specific for BD than schizophrenia; brief limited intermittent psychotic symptoms (BLIPS) were more likely to be part of EOSSD. In contrast, attenuated psychotic symptoms, and negative symptoms were not specifically related to the diagnosis of EOSSD. In conclusion, subsyndromal manic symptoms, BLIPS, and ADHD might be useful for predicting the trajectory of an emerging affective disorder versus schizophrenia and thus valuable for early detection, and intervention strategies.