Spatial frequency discrimination in patients with schizophrenia spectrum and bipolar disorders: Evidence of early visual processing deficits and associations with intellectual abilities

Objective: Low-level sensory disruption is hypothesized as a precursor to clinical and cognitive symptoms in severe mental disorders. We compared visual discrimination performance in patients with schizophrenia spectrum disorder or bipolar disorder with healthy controls, and investigated associations with clinical symptoms and IQ. Methods: Patients with schizophrenia spectrum disorder (n=32), bipolar disorder (n=55) and healthy controls (n=152) completed a computerized visual discrimination task. Participants responded whether the latter of two consecutive grids had higher or lower spatial frequency, and discrimination thresholds were estimated using an adaptive maximum likelihood procedure. Case-control differences in threshold were assessed using linear regression, F-test and post-hoc pair-wise comparisons. Linear models were used to test for associations between visual discrimination threshold and psychotic symptoms derived from the PANSS and IQ assessed using the Matrix Reasoning and Vocabulary subtests from the Wechsler Abbreviated Scale of Intelligence (WASI). Results: Robust regression revealed a significant main effect of diagnosis on discrimination threshold (robust F=6.76, p=.001). Post-hoc comparisons revealed that patients with a schizophrenia spectrum disorder (mean=14%, SD=0.08) had higher thresholds compared to healthy controls (mean=10.8%, SD = 0.07, β = 0.35, t=3.4, p=0.002), as did patients with bipolar disorder (12.23%, SD=0.07, β= 0.21, t=2.42, p=0.04). There was no significant difference between bipolar disorder and schizophrenia (β=-0.14, t=-1.2, p=0.45). Linear models revealed negative associations between IQ and threshold across all participants when controlling for diagnostic group (β = -0.3, t=-3.43, p=0.0007). This association was found within healthy controls (t=-3.72, p=.0003) and patients with bipolar disorder (t=-2.53, p=.015), and no significant group by IQ interaction on threshold (F=0.044, p=.97). There were no significant associations between PANSS domain scores and discrimination threshold. Conclusion: Patients with schizophrenia spectrum or bipolar disorders exhibited higher visual discrimination thresholds than healthy controls, supporting early visual deficits among patients with severe mental illness. Discrimination threshold was negatively associated with IQ among healthy controls and bipolar disorder patients. These findings elucidate perception-related disease mechanisms in severe mental illness, which warrants replication in independent samples.

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Traumatic Stress Disorders and Risk of Subsequent Schizophrenia Spectrum Disorder or Bipolar Disorder: A Nationwide Cohort Study

Schizophrenia Bulletin ◽

10.1093/schbul/sbw082 ◽

2016 ◽

Vol 43 (1) ◽

pp. 180-186 ◽

Cited By ~ 23

Author(s):

Niels Okkels ◽

Betina Trabjerg ◽

Mikkel Arendt ◽

Carsten Bøcker Pedersen

Keyword(s):

Bipolar Disorder ◽

Cohort Study ◽

Traumatic Stress ◽

Spectrum Disorder ◽

Stress Disorders ◽

Schizophrenia Spectrum Disorder ◽

Schizophrenia Spectrum ◽

Traumatic Stress Disorders

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T73. COGNITIVE CLUSTERING IN SCHIZOPHRENIA SPECTRUM DISORDER AND THE ASSOCIATION WITH BRAIN VOLUME

Schizophrenia Bulletin ◽

10.1093/schbul/sbaa029.633 ◽

2020 ◽

Vol 46 (Supplement_1) ◽

pp. S259-S259

Author(s):

Priscilla Oomen ◽

Marieke Begemann ◽

Hannah de Muinck Keizer ◽

Iris Sommer

Keyword(s):

Hierarchical Clustering ◽

Brain Volume ◽

Spectrum Disorder ◽

Healthy Controls ◽

Cognitive Profiles ◽

Schizophrenia Spectrum Disorder ◽

Whole Brain ◽

Schizophrenia Spectrum ◽

Significant Difference ◽

Cluster 2

Abstract Background Cognitive impairment is a core feature of schizophrenia spectrum disorder (SSD), and appears in both mild and severe forms. As cognition is crucial for functioning in daily life, it is important to understand these impairments. Large heterogeneity exists within these cognitive impairments, and different cognitive profiles may be associated with dissimilar structural brain volumes. Such cognitive brain profiles may be relevant biomarkers for more homogeneous subclasses to be used for both prognosis and choice of optimal care. Methods The population consisted of 85 individuals with schizophrenia spectrum disorder (mean age 27 years, 64 males) and 40 healthy controls (mean age 24 years, 31 males). To identify cognitive clusters, hierarchical clustering analyses were conducted using performance on the Brief Assessment of Cognition in Schizophrenia (BACS) battery. The emerging cognitive clusters were compared in performance on the BACS, diagnosis and whole brain volume. Results Hierarchical clustering analyses revealed three cognitive profiles: cluster 1 “relatively intact” cluster 2 “mild-moderate impairment” and cluster 3 “severe impairment”. Cluster 1 comprised of 68% healthy controls vs 32% SSD patients, whereas clusters 3 comprised of 89% SSD patients vs 11% healthy controls. Cluster 2 was a rather mixed cluster with 25% healthy controls and 75% SSD patients. Whole brain volume shows a continuum towards smaller brain volume in the more impaired clusters with a significant difference shown in whole brain volume between cluster 1 and 3. Discussion These findings support the concept that cognitive heterogeneity among individuals with schizophrenia spectrum disorder can be reduced by using cognitive clustering methods. Furthermore, cognitive clusters are associated with brain volume sizes, indicating different underlying brain structure. Future research should focus on the predictive power of such clusters.

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Prevalence and correlates of major depressive disorder, bipolar disorder and schizophrenia among nursing home residents without dementia: systematic review and meta-analysis

The British Journal of Psychiatry ◽

10.1192/bjp.2019.5 ◽

2019 ◽

Vol 216 (1) ◽

pp. 6-15 ◽

Cited By ~ 2

Author(s):

Michele Fornaro ◽

Marco Solmi ◽

Brendon Stubbs ◽

Nicola Veronese ◽

Francesco Monaco ◽

...

Keyword(s):

Systematic Review ◽

Bipolar Disorder ◽

Major Depressive Disorder ◽

Nursing Homes ◽

Depressive Disorder ◽

Meta Analysis ◽

Spectrum Disorder ◽

Schizophrenia Spectrum Disorder ◽

Major Depressive ◽

Schizophrenia Spectrum

BackgroundThe elderly population and numbers of nursing homes residents are growing at a rapid pace globally. Uncertainty exists regarding the actual rates of major depressive disorder (MDD), bipolar disorder and schizophrenia as previous evidence documenting high rates relies on suboptimal methodology.AimsTo carry out a systematic review and meta-analysis on the prevalence and correlates of MDD, bipolar disorder and schizophrenia spectrum disorder among nursing homes residents without dementia.MethodMajor electronic databases were systematically searched from 1980 to July 2017 for original studies reporting on the prevalence and correlates of MDD among nursing homes residents without dementia. The prevalence of MDD in this population was meta-analysed through random-effects modelling and potential sources of heterogeneity were examined through subgroup/meta-regression analyses.ResultsAcross 32 observational studies encompassing 13 394 nursing homes residents, 2110 people were diagnosed with MDD, resulting in a pooled prevalence rate of 18.9% (95% CI 14.8–23.8). Heterogeneity was high (I2 = 97%, P≤0.001); no evidence of publication bias was observed. Sensitivity analysis indicated the highest rates of MDD among North American residents (25.4%, 95% CI 18–34.5, P≤0.001). Prevalence of either bipolar disorder or schizophrenia spectrum disorder could not be reliably pooled because of the paucity of data.ConclusionsMDD is highly prevalent among nursing homes residents without dementia. Efforts towards prevention, early recognition and management of MDD in this population are warranted.

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Physical health behaviours and health locus of control in people with schizophrenia-spectrum disorder and bipolar disorder: a cross-sectional comparative study with people with non-psychotic mental illness

BMC Psychiatry ◽

10.1186/1471-244x-11-104 ◽

2011 ◽

Vol 11 (1) ◽

Cited By ~ 38

Author(s):

Kurt Buhagiar ◽

Liam Parsonage ◽

David PJ Osborn

Keyword(s):

Bipolar Disorder ◽

Mental Illness ◽

Locus Of Control ◽

Comparative Study ◽

Physical Health ◽

Health Behaviours ◽

Spectrum Disorder ◽

Schizophrenia Spectrum Disorder ◽

Cross Sectional ◽

Schizophrenia Spectrum

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Semantic Memory Impairment Across the Schizophrenia Continuum: A Meta-Analysis of Category Fluency Performance

Schizophrenia Bulletin Open ◽

10.1093/schizbullopen/sgaa054 ◽

2020 ◽

Vol 1 (1) ◽

Author(s):

Eric Josiah Tan ◽

Erica Neill ◽

Kiandra Tomlinson ◽

Susan Lee Rossell

Keyword(s):

Semantic Memory ◽

Cluster Size ◽

Spectrum Disorder ◽

Healthy Controls ◽

Chronic Patients ◽

Schizophrenia Spectrum Disorder ◽

Illness Onset ◽

First Degree Relatives ◽

Schizophrenia Spectrum ◽

Category Fluency

Abstract Semantic memory (SM) impairments are a core feature of schizophrenia and are present along the psychosis continuum. It is, however, unclear whether the degree of SM impairments vary along this continuum and if demographic and clinical factors affect impairment severity. This study performed meta-analyses of category fluency task performance (a task commonly used to assess SM) in 4 groups along the schizophrenia continuum: high schizotypes (HSZT), first-degree relatives (FDR), recent-onset patients (≤2 y; ROP) and chronic patients (CSZ). Electronic databases were searched for relevant studies published up to October 2019 resulting in the inclusion of 48 articles. The main analyses assessed fluency productivity scores in 2978 schizophrenia spectrum disorder patients, 340 first-degree relatives of schizophrenia spectrum disorder patients, and 3204 healthy controls. Further analyses assessed errors, mean cluster size, and switching data that were available in the CSZ group only. Results revealed significant impairments in fluency productivity were present in the FDR, ROP, and CSZ groups relative to healthy controls, but not in HSZT. In the CSZ group, significant differences relative to healthy controls were also observed in non-perseverative errors, mean cluster size, and number of switches. The findings collectively suggest that SM deficits are present at each stage of the continuum and are exacerbated post-illness onset. They also support the centrality of SM impairments in schizophrenia and most elevated risk groups. Future studies with more diverse measures of SM function are needed to replicate and extend this research.

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