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1.
Schizophr Bull ; 50(1): 177-186, 2024 Jan 01.
Article in English | MEDLINE | ID: mdl-37606284

ABSTRACT

BACKGROUND AND HYPOTHESIS: Individuals at familial risk for developing schizophrenia (FRSZ) or bipolar disorder (FRBD) have shared and unique genetic risks. Few studies have compared neural activation between these two groups. Therefore, the present meta-analysis investigated functional brain similarities and differences between FRSZ and FRBD individuals. STUDY DESIGN: A systematic literature review was conducted of articles that compared FRSZ or FRBD individuals to healthy controls (31 FRSZ and 22 FRBD). Seed-based d mapping was used to conduct the meta-analysis. Analyses included comparisons of FRSZ to controls, FRBD to controls, and both relative groups to each other. STUDY RESULTS: Using a highly conservative family-wise error rate correction, there were no significant findings. Using a less conservative threshold, FRSZ compared to controls had lower activation in the left precuneus (Puncorrected = .02) across all studies and in the left middle frontal gyrus (Puncorrected = .03) in nonsocial cognition studies. FRBD compared to controls had lower activation in the left superior parietal gyrus (Puncorrected = .03) and right angular gyrus (Puncorrected = .03) in nonsocial cognition studies, and higher activation in the left superior frontal gyrus (Puncorrected = .01) in social tasks. Differences between FRSZ and FRBD were not significant. CONCLUSIONS: There were few robust differences between FRSZ or FRBD compared to controls. This suggests only weak support for neural activation differences between individuals at genetic risk for schizophrenia or bipolar disorder and controls. The tentative findings observed were in different brain regions for FRSZ and FRBD, with no strong evidence for shared effects between schizophrenia and bipolar genetic risk on neural activation.


Subject(s)
Bipolar Disorder , Schizophrenia , Humans , Bipolar Disorder/diagnostic imaging , Bipolar Disorder/genetics , Bipolar Disorder/pathology , Schizophrenia/diagnostic imaging , Schizophrenia/genetics , Schizophrenia/pathology , Brain , Magnetic Resonance Imaging/methods , Genetic Predisposition to Disease
2.
Schizophr Bull ; 49(4): 1022-1031, 2023 07 04.
Article in English | MEDLINE | ID: mdl-36752824

ABSTRACT

BACKGROUND AND HYPOTHESIS: Attenuated Psychosis Syndrome (APS) impacts functioning and predicts increased risk of psychosis. Risk for developing APS itself has received minimal attention. Knowledge of familial and environmental contributions to APS symptoms would advance understanding of APS and risk for psychosis. As an initial step, this report presents the first data on APS symptoms in family members of APS patients. STUDY DESIGN: This study utilized a discordant sibling-pair family study design. The Structured Interview for Psychosis-risk Syndromes (SIPS) was administered to 17 APS probands and 26 non-APS biological siblings. Probands and siblings were compared on positive, negative, disorganized, and general SIPS symptom scales and factors derived from those scales. STUDY RESULTS: There was significantly greater symptom severity in probands compared to siblings on nine of 19 SIPS scales. Negative/anxiety, functioning, and positive symptom factors were identified. Probands showed significantly greater severity than siblings on the negative/anxiety and positive factors. Elevated pathology on the negative/anxiety factor best differentiated between probands and siblings, over and above the contribution of the positive factor. No difference was found for the functioning factor. CONCLUSIONS: Results support the importance of non-familial effects on risk for APS and suggest differences in familial contribution to APS symptoms. Understanding the relative contribution of familial and environmental effects on APS symptoms may reveal important differences among APS patients, with implications for risk characterization, symptom course, and treatment selection.


Subject(s)
Psychotic Disorders , Humans , Adolescent , Syndrome , Psychotic Disorders/genetics , Psychotic Disorders/diagnosis , Family , Anxiety , Siblings , Prodromal Symptoms
3.
J Psychopathol Clin Sci ; 131(6): 674-688, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35737559

ABSTRACT

Risk for schizophrenia peaks during early adulthood, a critical period for brain development. Although several influential theoretical models have been proposed for the developmental relationship between brain pathology and clinical onset, to our knowledge, no study has directly evaluated the predictions of these models for schizophrenia developmental genetic effects on brain structure. To address this question, we introduce a framework to estimate the effects of schizophrenia genetic variation on brain structure phenotypes across the life span. Five-hundred and six participants, including 30 schizophrenia probands, 200 of their relatives (aged 12-85 years) from 32 families with at least two first-degree schizophrenia relatives, and 276 unrelated controls, underwent MRI to assess regional cortical thickness (CT) and cortical surface area (CSA). Genetic variance decomposition analyses were conducted to distinguish among schizophrenia neurogenetic effects that are most salient before schizophrenia peak age-of-risk (i.e., early neurodevelopmental effects), after peak age-of-risk (late neurodevelopmental effects), and during the later plateau of age-of-risk (neurodegenerative effects). Genetic correlations between schizophrenia and cortical traits suggested early neurodevelopmental effects for frontal and insula CSA, late neurodevelopmental effects for overall CSA and frontal, parietal, and occipital CSA, and possible neurodegenerative effects for temporal CT and parietal CSA. Importantly, these developmental neurogenetic effects were specific to schizophrenia and not found with nonpsychotic depression. Our findings highlight the potentially dynamic nature of schizophrenia genetic effects across the lifespan and emphasize the utility of integrating neuroimaging methods with developmental behavior genetic approaches to elucidate the nature and timing of risk-conferring processes in psychopathology. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Subject(s)
Schizophrenia , Brain/pathology , Cerebral Cortex/diagnostic imaging , Humans , Magnetic Resonance Imaging , Schizophrenia/diagnostic imaging , Temporal Lobe/pathology
4.
Schizophr Res ; 246: 39-48, 2022 08.
Article in English | MEDLINE | ID: mdl-35709646

ABSTRACT

Cognition shares substantial genetic overlap with schizophrenia, yet it remains unclear whether such genetic effects become significant during developmental periods of elevated risk for schizophrenia, such as the peak age of onset. We introduce an investigative framework integrating epidemiological, developmental, and genetic approaches to determine whether genetic effects shared between schizophrenia and cognition are significant across periods of differing risk for schizophrenia onset, and whether these effects are shared with depression. 771 European-American participants, including 636 (ages 15-84 years) from families with at least two first-degree relatives with schizophrenia and 135 unrelated controls, were divided into three age-risk groups based on ages relative to epidemiological age of onset patterns for schizophrenia: Pre-Peak (before peak age-of-onset: 15 to 22 years), Post-Peak (after peak age-of-onset: 23-42 years), and Plateau (during plateau of age-of-onset: over 42 years). For general cognition and 11 specific cognitive traits, we estimated genetic correlations with schizophrenia and with depression within each age-risk group. Genetic effects shared between deficits in general cognition and schizophrenia were nonsignificant before peak age of onset, yet were high and significant after peak age of onset and during the plateau of onset. These age-dependent genetic effects were largely consistent across specific cognitive traits and not transdiagnostically shared with depression. Schizophrenia genetic effects appear to influence cognitive traits in an age-dependent manner, supporting late developmental and perhaps neurodegenerative models that hypothesize increased expression of schizophrenia risk genes during and after the peak age of risk. Our findings underscore the utility of cognitive traits for tracking schizophrenia genetic effects across the lifespan.


Subject(s)
Schizophrenia , Adolescent , Adult , Aged , Aged, 80 and over , Cognition , Humans , Middle Aged , Phenotype , Risk Factors , Schizophrenia/epidemiology , Schizophrenia/genetics , Young Adult
5.
Am J Med Genet B Neuropsychiatr Genet ; 183(7): 403-411, 2020 10.
Article in English | MEDLINE | ID: mdl-32812349

ABSTRACT

Schizophrenia has substantial variation in symptom severity, course of illness, and overall functioning. Earlier age of onset (AOO) is consistently associated with negative outcomes and yet the causes of this association are still unknown. We used a multiplex, extended pedigree design (total N = 771; 636 relatives from 43 multigenerational families with at least 2 relatives diagnosed with schizophrenia and 135 matched controls) to examine among the schizophrenia relatives (N = 103) the relationship between AOO and negative and positive symptom severity, cognition, and community functioning. Most importantly, we assessed whether there are shared genetic effects between AOO and negative symptoms, positive symptoms, cognition, and community functioning. As expected, earlier AOO was significantly correlated with increased severity of negative and positive symptoms and poorer cognition and community functioning among schizophrenia patients. Notably, the genetic correlation between AOO of schizophrenia and negative symptoms was significant (Rg = -1.00, p = .007). Although the genetic correlations between AOO and positive symptoms, cognition, and community functioning were estimated at maximum and in the predicted direction, they were not statistically significant. AOO of schizophrenia itself was modestly heritable, although not significant and negative symptoms, positive symptoms, and cognition were all strongly and significantly heritable. In sum, we replicated prior findings indicating that earlier AOO is associated with increased symptom severity and extended the literature by detecting shared genetic effects between AOO and negative symptoms, suggestive of pleiotropy.


Subject(s)
Schizophrenia/genetics , Schizophrenia/physiopathology , Adult , Age Factors , Age of Onset , Family/psychology , Female , Humans , Male , Middle Aged , Neuropsychological Tests , Pedigree , Psychiatric Status Rating Scales , Schizophrenic Psychology , Severity of Illness Index
7.
Neurosci Biobehav Rev ; 98: 85-94, 2019 03.
Article in English | MEDLINE | ID: mdl-30615934

ABSTRACT

Despite hundreds of structural MRI studies documenting smaller brain volumes on average in schizophrenia compared to controls, little attention has been paid to group differences in the variability of brain volumes. Examination of variability may help interpret mean group differences in brain volumes and aid in better understanding the heterogeneity of schizophrenia. Variability in 246 MRI studies was meta-analyzed for 13 structures that have shown medium to large mean effect sizes (Cohen's d≥0.4): intracranial volume, total brain volume, lateral ventricles, third ventricle, total gray matter, frontal gray matter, prefrontal gray matter, temporal gray matter, superior temporal gyrus gray matter, planum temporale, hippocampus, fusiform gyrus, insula; and a control structure, caudate nucleus. No significant differences in variability in cortical/subcortical volumes were detected in schizophrenia relative to controls. In contrast, increased variability was found in schizophrenia compared to controls for intracranial and especially lateral and third ventricle volumes. These findings highlight the need for more attention to ventricles and detailed analyses of brain volume distributions to better elucidate the pathophysiology of schizophrenia.


Subject(s)
Cerebral Cortex/physiopathology , Gray Matter/physiopathology , Hippocampus/physiopathology , Schizophrenia/physiopathology , Animals , Brain Stem/pathology , Brain Stem/physiopathology , Cerebral Cortex/pathology , Gray Matter/pathology , Hippocampus/pathology , Humans , Magnetic Resonance Imaging/methods , Schizophrenia/diagnosis
8.
J Abnorm Psychol ; 127(2): 216-227, 2018 02.
Article in English | MEDLINE | ID: mdl-29528675

ABSTRACT

Although cognition is one of the most important predictors of community functioning in schizophrenia, little is known about the causes of this correlation. To our knowledge, this study is the first to examine the extent to which this correlation is genetically mediated and whether the genetic correlation is specific to schizophrenia. Six hundred thirty-six participants from 43 multigenerational families with at least two relatives with schizophrenia and 135 unrelated controls underwent diagnostic interview and cognition and functioning assessment. Quantitative genetic analyses were conducted using maximum-likelihood variance decomposition methods implemented in SOLAR (Almasy & Blangero, 1998). Among patients with schizophrenia, cognition and community functioning were positively correlated and genetic effects shared between them were significant contributors to this relationship whereas environmental effects shared between them were not. In contrast, genetic effects were not shared significantly between cognition in depressed or nondiagnosed relatives and community functioning in schizophrenia. In all analyses, the contributions of social cognition to community functioning were accounted for by general cognition. These findings support heritable factors that contribute to the correlation between cognition and community functioning that are relatively specific to schizophrenia and are not significantly shared with depression or a lack of psychopathology. This suggests the possibility of identifying specific genetic variants that contribute to this correlation and to these important individual differences among schizophrenia patients. (PsycINFO Database Record


Subject(s)
Cognition , Schizophrenia/genetics , Schizophrenic Psychology , Social Behavior , Adult , Female , Humans , Independent Living/psychology , Male , Middle Aged , Neuropsychological Tests
9.
Am J Med Genet B Neuropsychiatr Genet ; 174(8): 817-827, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28902459

ABSTRACT

Schizophrenia is a serious mental illness, involving disruptions in thought and behavior, with a worldwide prevalence of about one percent. Although highly heritable, much of the genetic liability of schizophrenia is yet to be explained. We searched for susceptibility loci in multiplex, multigenerational families affected by schizophrenia, targeting protein-altering variation with in silico predicted functional effects. Exome sequencing was performed on 136 samples from eight European-American families, including 23 individuals diagnosed with schizophrenia or schizoaffective disorder. In total, 11,878 non-synonymous variants from 6,396 genes were tested for their association with schizophrenia spectrum disorders. Pathway enrichment analyses were conducted on gene-based test results, protein-protein interaction (PPI) networks, and epistatic effects. Using a significance threshold of FDR < 0.1, association was detected for rs10941112 (p = 2.1 × 10-5 ; q-value = 0.073) in AMACR, a gene involved in fatty acid metabolism and previously implicated in schizophrenia, with significant cis effects on gene expression (p = 5.5 × 10-4 ), including brain tissue data from the Genotype-Tissue Expression project (minimum p = 6.0 × 10-5 ). A second SNP, rs10378 located in TMEM176A, also shows risk effects in the exome data (p = 2.8 × 10-5 ; q-value = 0.073). PPIs among our top gene-based association results (p < 0.05; n = 359 genes) reveal significant enrichment of genes involved in NCAM-mediated neurite outgrowth (p = 3.0 × 10-5 ), while exome-wide SNP-SNP interaction effects for rs10941112 and rs10378 indicate a potential role for kinase-mediated signaling involved in memory and learning. In conclusion, these association results implicate AMACR and TMEM176A in schizophrenia risk, whose effects may be modulated by genes involved in synaptic plasticity and neurocognitive performance.


Subject(s)
Exome , Genetic Markers , Neurocognitive Disorders/genetics , Polymorphism, Single Nucleotide , Schizophrenia/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Case-Control Studies , Family , Female , Genetic Predisposition to Disease , Genome-Wide Association Study , Humans , Male , Mental Status and Dementia Tests , Middle Aged , Neurocognitive Disorders/diagnosis , Neurocognitive Disorders/epidemiology , Risk Factors , Schizophrenia/complications , Young Adult
10.
Schizophr Bull ; 42(2): 288-300, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26405221

ABSTRACT

Schizophrenia is a mental disorder characterized by impairments in behavior, thought, and neurocognitive performance. We searched for susceptibility loci at a quantitative trait locus (QTL) previously reported for abstraction and mental flexibility (ABF), a cognitive function often compromised in schizophrenia patients and their unaffected relatives. Exome sequences were determined for 134 samples in 8 European American families from the original linkage study, including 25 individuals with schizophrenia or schizoaffective disorder. At chromosome 5q32-35.3, we analyzed 407 protein-altering variants for association with ABF and schizophrenia status. For replication, significant, Bonferroni-corrected findings were tested against cognitive traits in Mexican American families (n = 959), as well as interrogated for schizophrenia risk using GWAS results from the Psychiatric Genomics Consortium (PGC). From the gene SYNPO, rs6579797 (MAF = 0.032) shows significant associations with ABF (P = .015) and schizophrenia (P = .040), as well as jointly (P = .0027). In the Mexican American pedigrees, rs6579797 exhibits significant associations with IQ (P = .011), indicating more global effects on neurocognition. From the PGC results, other SYNPO variants were identified with near significant effects on schizophrenia risk, with a local linkage disequilibrium block displaying signatures of positive selection. A second missense variant within the QTL, rs17551608 (MAF = 0.19) in the gene WWC1, also displays a significant effect on schizophrenia in our exome sequences (P = .038). Remarkably, the protein products of SYNPO and WWC1 are interaction partners involved in AMPA receptor trafficking, a brain process implicated in synaptic plasticity. Our study reveals variants in these genes with significant effects on neurocognition and schizophrenia risk, identifying a potential pathogenic mechanism for schizophrenia spectrum disorders.


Subject(s)
Cognition Disorders/genetics , Exome/genetics , Intracellular Signaling Peptides and Proteins/metabolism , Microfilament Proteins/metabolism , Phosphoproteins/metabolism , Receptors, Glutamate/metabolism , Schizophrenia/genetics , Genome-Wide Association Study , Humans , Intracellular Signaling Peptides and Proteins/genetics , Microfilament Proteins/genetics , Pedigree , Phosphoproteins/genetics , Quantitative Trait Loci
11.
Schizophr Res ; 161(2-3): 478-83, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25510926

ABSTRACT

Substance use is a frequent problem in schizophrenia, and although many substance misusing patients with the disorder also experience considerable cognitive impairments, such individuals have been routinely excluded from clinical trials of cognitive remediation that could support their functional and addiction recoveries. This study conducted a small-scale feasibility trial of Cognitive Enhancement Therapy (CET) in substance misusing schizophrenia patients to assess the feasibility and efficacy of implementing comprehensive neurocognitive and social-cognitive remediation in this population. A total of 31 schizophrenia outpatients meeting addiction severity criteria for alcohol and/or cannabis use were randomized to 18months of CET or usual care. Feasibility findings indicated high degrees of satisfaction with CET, but also presented significant challenges in the recruitment and retention of substance misusing patients, with high levels of attrition (50%) over the study period, primarily due to positive symptom exacerbation. Intent-to-treat efficacy analyses showed large and significant improvements in neurocognition (d=.86), social cognition (d=1.13), and social adjustment (d=.92) favoring CET. Further, individuals treated with CET were more likely to reduce alcohol use (67% in CET vs. 25% in usual care) during treatment (p=.021). These results suggest that once engaged and stabilized, CET is a feasible and potentially effective treatment for cognitive impairments in patients with schizophrenia who misuse alcohol and/or cannabis. Substance misusing patients who are able to engage in treatment may be able to benefit from cognitive remediation, and the treatment of cognitive impairments may help improve substance use outcomes among this underserved population.


Subject(s)
Alcoholism/complications , Cognitive Behavioral Therapy/methods , Marijuana Abuse/complications , Psychotic Disorders/therapy , Schizophrenia/therapy , Adult , Alcoholism/psychology , Alcoholism/therapy , Cognition , Feasibility Studies , Female , Humans , Male , Marijuana Abuse/psychology , Marijuana Abuse/therapy , Psychotic Disorders/complications , Psychotic Disorders/psychology , Schizophrenia/complications , Schizophrenic Psychology , Social Adjustment , Social Perception , Treatment Outcome
12.
Biol Psychiatry ; 77(2): 137-46, 2015 Jan 15.
Article in English | MEDLINE | ID: mdl-24976379

ABSTRACT

BACKGROUND: Brain abnormalities of subcortical and limbic nuclei are common in patients with schizophrenia, and variation in these structures is considered a putative endophenotype for the disorder. Multiplex-multigenerational families with schizophrenia provide an opportunity to investigate the impact of shared genetic ancestry, but these families have not been previously examined to study structural brain abnormalities. We estimate the heritability of subcortical and hippocampal brain volumes in multiplex-multigenerational families and the heritability of subregions using advanced shape analysis. METHODS: The study comprised 439 participants from two sites who underwent 3T structural magnetic resonance imaging. The participants included 190 European-Americans from 32 multiplex-multigenerational families with schizophrenia and 249 healthy comparison subjects. Subcortical and hippocampal volume and shape were measured in 14 brain structures. Heritability was estimated for volume and shape. RESULTS: Volume and shape were heritable in families. Estimates of heritability in subcortical and limbic volumes ranged from .45 in the right hippocampus to .84 in the left putamen. The shape of these structures was heritable (range, .40-.49), and specific subregional shape estimates of heritability tended to exceed heritability estimates of volume alone. CONCLUSIONS: These results demonstrate that volume and shape of subcortical and limbic brain structures are potential endophenotypic markers in schizophrenia. The specificity obtained using shape analysis may improve selection of imaging phenotypes that better reflect the underlying neurobiology. Our findings can aid in the identification of specific genetic targets that affect brain structure and function in schizophrenia.


Subject(s)
Brain/pathology , Schizophrenia/genetics , Schizophrenia/pathology , Adult , Cohort Studies , Endophenotypes , Family , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Organ Size , United States , White People
13.
Neuropsychology ; 28(2): 161-176, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24364396

ABSTRACT

OBJECTIVE: The advent of functional MRI (fMRI) enables the identification of brain regions recruited for specific behavioral tasks. Most fMRI studies focus on group effects in single tasks, which limits applicability where assessment of individual differences and multiple brain systems is needed. METHOD: We demonstrate the feasibility of concurrently measuring fMRI activation patterns and performance on a computerized neurocognitive battery (CNB) in 212 healthy individuals at 2 sites. Cross-validated sparse regression of regional brain amplitude and extent of activation were used to predict concurrent performance on 6 neurocognitive tasks: abstraction/mental flexibility, attention, emotion processing, and verbal, face, and spatial memory. RESULTS: Brain activation was task responsive and domain specific, as reported in previous single-task studies. Prediction of performance was robust for most tasks, particularly for abstraction/mental flexibility and visuospatial memory. CONCLUSIONS: The feasibility of administering a comprehensive neuropsychological battery in the scanner was established, and task-specific brain activation patterns improved prediction beyond demographic information. This benchmark index of performance-associated brain activation can be applied to link brain activation with neurocognitive performance during standardized testing. This first step in standardizing a neurocognitive battery for use in fMRI may enable quantitative assessment of patients with brain disorders across multiple cognitive domains. Such data may facilitate identification of neural dysfunction associated with poor performance, allow for identification of individuals at risk for brain disorders, and help guide early intervention and rehabilitation of neurocognitive deficits.


Subject(s)
Brain Mapping , Brain/physiology , Cognition/physiology , Magnetic Resonance Imaging , Neuropsychological Tests , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Regression Analysis , Young Adult
14.
Schizophr Bull ; 39(5): 1008-17, 2013 Sep.
Article in English | MEDLINE | ID: mdl-22927671

ABSTRACT

Certain cognitive measures are heritable and differentiate individuals at risk for schizophrenia from unaffected family members and healthy comparison subjects. These deficits in neurocognitive performance in patients with schizophrenia appear stable in the short-term. However, the duration of most, but not all, longitudinal studies is modest and the majority have relied on traditional average performance measures to examine stability. Using a computerized neurocognitive battery (CNB), we assessed mean performance (accuracy and speed) and intra-individual variability (IIV) in a longitudinal study aimed to examine neurocognitive stability in European-American multiplex families with schizophrenia. Thirty-four patients with schizophrenia, 65 unaffected relatives, and 45 healthy comparison subjects completed the same computerized neurocognitive assessment over approximately 5 years. Measures of mean performance showed that patients had stable accuracy performance but were slower in many neurocognitive domains over time as compared with unaffected family members and healthy subjects. Furthermore, patients and family members showed dissociable patterns of change in IIV for speed across cognitive domains: compared with controls, patients showed higher across-task IIV in performance compared with family members, who showed lower across-task IIV. Patients showed an increase in IIV over time, whereas family members showed a decrease. These findings suggest that measures of mean performance and IIV of speed during a CNB may provide useful information about the genetic susceptibility in schizophrenia.


Subject(s)
Cognition Disorders/diagnosis , Neuropsychological Tests , Schizophrenia/diagnosis , Adolescent , Adult , Aged , Aged, 80 and over , Cognition Disorders/etiology , Cognition Disorders/genetics , Female , Genetic Predisposition to Disease , Humans , Longitudinal Studies , Male , Middle Aged , Neuropsychological Tests/statistics & numerical data , Schizophrenia/complications , Schizophrenia/genetics , Task Performance and Analysis , Time Factors , White People/genetics , White People/psychology , Young Adult
15.
J Abnorm Psychol ; 121(2): 396-406, 2012 May.
Article in English | MEDLINE | ID: mdl-22288909

ABSTRACT

Identification of endophenotypes (Gottesman & Gould, 2003; Gottesman & Shields, 1972) that genetically correlate with schizophrenia and are genetically homogeneous is an important strategy for detecting genes that affect schizophrenia risk. Symptoms of schizotypy may familially correlate with schizophrenia; however, there are critical limitations of the current literature concerning this association. The present study examined the genetic architecture and genetic associations between schizotypy and schizophrenia among multigenerational, multiplex schizophrenia families. Genetic schizotypy factor scales were developed that genetically correlated with schizophrenia, although some relations were unexpected in direction suggesting minimization of "psychotic-like" symptoms. These genetic schizotypy factor scales did not genetically correlate with major depressive disorder or substance dependence indicating specificity to schizophrenia. The results highlight the possibility of significant response bias in schizophrenia families, particularly among close relatives, and suggest an important consideration when acquiring self-report information. This is a topic that deserves future study as the origins of this putative bias in relatives are unclear. In addition, the results support the identification of genetic schizotypy factors as a promising technique for maximizing genetic correlation of endophenotypes with schizophrenia.


Subject(s)
Schizophrenia/genetics , Schizophrenic Psychology , Schizotypal Personality Disorder/etiology , Adult , Case-Control Studies , Depressive Disorder, Major/genetics , Female , Genetic Predisposition to Disease , Humans , Male , Middle Aged , Pedigree , Psychiatric Status Rating Scales , Substance-Related Disorders/genetics
16.
Psychiatr Genet ; 22(2): 70-81, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22183611

ABSTRACT

OBJECTIVES: Recent work shows promising associations between schizophrenia and polymorphisms in neuregulin-1 (NRG1) and a large literature also finds strong familial relationships between schizophrenia and cognitive deficits. Given the role of NRG1 in glutamate regulation and glutamate's effect on cognition, we hypothesized that cognitive deficits may be related to variation within NRG1, providing a possible mechanism to increase risk for schizophrenia. METHODS: This study examined the associations between NRG1, cognition, and schizophrenia using a multigenerational multiplex family sample (total N=419, 40 families), including 58 affected participants (schizophrenia or schizoaffective disorder-depressed type) and their 361 unaffected relatives. Participants were genotyped for 40 NRG1 single nucleotide polymorphisms (SNPs), chosen largely based on previous associations with schizophrenia. All participants completed structured diagnostic interviews and a computerized neurocognitive battery assessing eight cognitive domains. Variance component quantitative trait analyses tested for associations between individual NRG1 SNPs and cognitive performance in the total sample, a subsample of healthy participants with no Diagnostic and Statistical Manual of Mental Disorders diagnosis, and using general intelligence as a covariate. RESULTS: Effect sizes (within-family ß coefficients) ranged from 0.08 to 0.73, and 61 of these associations were nominally significant (P≤0.05), with 12 associations at P≤0.01, although none achieved the modified Bonferroni significance threshold of P<0.0003. Attention was the most frequently nominally associated domain and rs10503929, a nonsynonymous SNP, was the most frequently nominally associated SNP. CONCLUSION: Although not significant experiment-wise, these findings suggest that further study of the associations between variation in NRG1 and cognition may be productive.


Subject(s)
Cognition , Genetic Diseases, Inborn/genetics , Neuregulin-1/genetics , Polymorphism, Single Nucleotide , Schizophrenia/genetics , Humans , Neuropsychological Tests
17.
Clin Psychol Rev ; 31(7): 1169-82, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21855827

ABSTRACT

Although generally accepted that schizotypal personality disorder diagnosis is more prevalent among relatives of individuals with schizophrenia and may be associated with genetic liability to schizophrenia, it seems likely that this diagnosis is itself heterogeneous and thus perhaps not as useful in identifying genes that affect schizophrenia risk (i.e. endophenotypes) as it could be. In contrast, symptoms and dimensions of schizotypal personality disorder may be more etiologically homogeneous, and thus more useful in genetic studies. The current review evaluated and consolidated evidence to date regarding specific symptoms and dimensions of schizotypal personality disorder among non-psychotic relatives of schizophrenia patients. Comparisons were made with relatives of affective disorder patients and non-psychiatric controls. Findings indicate strong support for elevation of social-interpersonal schizotypal symptoms among relatives of schizophrenia patients versus other groups along with moderate specificity. Results suggest only a small elevation of cognitive-perceptual and disorganized symptoms in relatives of schizophrenia patients and results for disorganized symptoms were inconsistent across studies. Thus, evidence to date supports further investigation of genetic associations between symptoms of schizotypal personality disorder and schizophrenia, and suggests that social-interpersonal symptoms may be particularly promising in genetic analyses of schizophrenia.


Subject(s)
Schizophrenia/genetics , Schizotypal Personality Disorder/genetics , Family/psychology , Humans , Psychiatric Status Rating Scales , Risk , Schizophrenia/diagnosis , Schizophrenic Psychology , Schizotypal Personality Disorder/diagnosis , Schizotypal Personality Disorder/psychology
18.
Schizophr Bull ; 36(5): 983-90, 2010 Sep.
Article in English | MEDLINE | ID: mdl-19282471

ABSTRACT

Polymorphisms of the gene encoding the regulator of G protein signaling, subtype 4 (RGS4), may be associated with schizophrenia. Among first-episode schizophrenia patients, they are also associated with dorsolateral prefrontal cortex (DLPFC) volume. The DLPFC is a key region that regulates heritable cognitive functions implicated in schizophrenia pathogenesis. To further understand the relationship of RGS4 variants to schizophrenia, we examined their associations with cognitive functions among schizophrenia patients and their relatives. We analyzed 31 multiplex, multigenerational Caucasian families with schizophrenia recruited on the basis of 2 affected first-degree relatives. All participants underwent a computerized neurocognitive battery that evaluates accuracy and speed (response time) of performance on abstraction/mental flexibility; attention; verbal, spatial, and face memory; and spatial ability. "Tag" single-nucleotide polymorphisms (SNPs) representing common polymorphisms were genotyped. Measured genotype analyses accounting for family relationships were performed using Sequential Oligogenic Linkage Analysis Routines. SNPs rs10917670 ("SNP1") and rs951439 ("SNP7") were associated with face memory speed (P = .0003) at a significance level that survived Bonferroni correction (P = .039). The same SNPs have earlier been reported to be associated with schizophrenia. There also were uncorrected associations with rs10917670 ("SNP1") and rs951439 ("SNP7") on face memory efficiency (P = .03) and verbal memory efficiency (P = 0.02), rs28757217 on abstraction/mental flexibility speed (P = .02) and verbal memory efficiency (P = .03), SNP18 (rs2661319) on spatial memory accuracy (P = 0.02) and face memory speed (P = .03). RGS4 polymorphisms are associated with variations in cognitive functions and contribute a small but statistically significant proportion of variance in a family-based sample.


Subject(s)
Alleles , Cognition Disorders/genetics , Genome-Wide Association Study , Neuropsychological Tests/statistics & numerical data , Polymorphism, Single Nucleotide/genetics , RGS Proteins/genetics , Schizophrenia/genetics , Schizophrenic Psychology , Adolescent , Adult , Aged , Aged, 80 and over , Base Sequence , Child , Chromosome Mapping , Cognition Disorders/diagnosis , Cognition Disorders/psychology , Face , Female , Genetic Variation , Genotype , Humans , Linkage Disequilibrium , Male , Mental Recall , Middle Aged , Neurons/physiology , Neurotransmitter Agents/metabolism , Pattern Recognition, Visual , Psychometrics , Schizophrenia/diagnosis , Signal Transduction/genetics , Young Adult
19.
Schizophr Bull ; 36(2): 370-80, 2010 Mar.
Article in English | MEDLINE | ID: mdl-18648021

ABSTRACT

The emotion management subscale of the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) has recently been recommended by the National Institute of Mental Health Measurement and Treatment Research to Improve Cognition in Schizophrenia committee as the sole measure of social cognition for trials of cognitive enhancement in schizophrenia, yet the psychometric properties of this subscale and the larger instrument in schizophrenia patients have not been thoroughly examined. This research presents a psychometric investigation of the MSCEIT in a sample of 64 early course outpatients with schizophrenia, schizoaffective, or schizophreniform disorder. Results demonstrated that the MSCEIT possesses adequate internal consistency reliability among its branch and total scales and that patients' branch and overall test performance was significantly below normative levels. Estimates of discriminant and concurrent validity indicated that the MSCEIT diverged from measures of neurocognitive functioning and psychopathology, but was only modestly related with objective measures of functional outcome. Convergent validity estimates suggested that, contrary to expectations, the MSCEIT did not correlate with a behavioral measure of social cognition. Finally, exploratory factor analyses suggested the possibility of a shift in the latent structure of emotional intelligence in schizophrenia, compared with studies with healthy individuals. These findings support the use of the MSCEIT as a reliable and potentially valid method of assessing the emotional components of social cognition in schizophrenia, but also point to a need for additional measurement development efforts to assess broader social-cognitive domains that may exhibit stronger relations with functional outcome. Further investigation is warranted to examine the instrument's latent factor structure and convergence with other measures of social cognition.


Subject(s)
Cognition Disorders/diagnosis , Emotional Intelligence , Psychiatric Status Rating Scales/statistics & numerical data , Psychotic Disorders/diagnosis , Psychotic Disorders/psychology , Schizophrenia/diagnosis , Schizophrenic Psychology , Adolescent , Adult , Antipsychotic Agents/therapeutic use , Cognition Disorders/drug therapy , Cognition Disorders/psychology , Female , Humans , Male , Psychometrics/statistics & numerical data , Psychotic Disorders/drug therapy , Reproducibility of Results , Schizophrenia/drug therapy , Social Adjustment , Young Adult
20.
Schizophr Res ; 114(1-3): 105-9, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19501486

ABSTRACT

The Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) is a key measure of social cognition recommended by the MATRICS committee. While the psychometric properties of the MSCEIT appear strong, previous evidence suggested its factor structure may have shifted when applied to schizophrenia patients, posing important implications for cross-group comparisons. Using multi-group confirmatory factor analysis, we explicitly tested the factorial invariance of the MSCEIT across schizophrenia (n=64) and two normative samples (n=2099 and 451). Results indicated that the factor structure of the MSCEIT was significantly different between the schizophrenia and normative samples. Implications for future research are discussed.


Subject(s)
Cognition/physiology , Emotions/physiology , Intelligence/physiology , Schizophrenia/physiopathology , Schizophrenic Psychology , Social Perception , Adult , Factor Analysis, Statistical , Female , Humans , Intelligence Tests , Male , Reference Values , Young Adult
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