Neurocognitive performance in family-based and case-control studies of schizophrenia

BACKGROUND

Neurocognitive deficits in schizophrenia (SZ) are established and the Consortium on the Genetics of Schizophrenia (COGS) investigated such measures as endophenotypes in family-based (COGS-1) and case-control (COGS-2) studies. By requiring family participation, family-based sampling may result in samples that vary demographically and perform better on neurocognitive measures.

METHODS

The Penn computerized neurocognitive battery (CNB) evaluates accuracy and speed of performance for several domains and was administered across sites in COGS-1 and COGS-2. Most tests were included in both studies. COGS-1 included 328 patients with SZ and 497 healthy comparison subjects (HCS) and COGS-2 included 1195 patients and 1009 HCS.

RESULTS

Demographically, COGS-1 participants were younger, more educated, with more educated parents and higher estimated IQ compared to COGS-2 participants. After controlling for demographics, the two samples produced very similar performance profiles compared to their respective controls. As expected, performance was better and with smaller effect sizes compared to controls in COGS-1 relative to COGS-2. Better performance was most pronounced for spatial processing while emotion identification had large effect sizes for both accuracy and speed in both samples. Performance was positively correlated with functioning and negatively with negative and positive symptoms in both samples, but correlations were attenuated in COGS-2, especially with positive symptoms.

CONCLUSIONS

Patients ascertained through family-based design have more favorable demographics and better performance on some neurocognitive domains. Thus, studies that use case-control ascertainment may tap into populations with more severe forms of illness that are exposed to less favorable factors compared to those ascertained with family-based designs.

Verbal working memory in schizophrenia from the Consortium on the Genetics of Schizophrenia (COGS) study: the moderating role of smoking status and antipsychotic medications

OBJECTIVES

Working memory impairment has been extensively studied in schizophrenia, but less is known about moderators of the impairment. Using the Consortium on the Genetics of Schizophrenia case-control study (COGS-2), we examined smoking status, types of antipsychotic medication, and history of substance as moderators for working memory impairment in schizophrenia.

METHODS

From 5 sites, 1377 patients with schizophrenia or schizoaffective, depressed type and 1037 healthy controls completed the letter-number span (LNS) task. The LNS uses intermixed letter and digit stimuli that increase from 2 up to 8 stimuli. In the forward condition, participants repeated the letters and numbers in the order they were presented. In the reorder condition, participants repeated the digits in ascending order followed by letters in alphabetical order.

RESULTS

Schizophrenia patients performed more poorly than controls, with a larger difference on reorder than forward conditions. Deficits were associated with symptoms, functional capacity, and functional outcome. Patients who smoked showed larger impairment than nonsmoking patients, primarily due to deficits on the reorder condition. The impairing association of smoking was more pronounced among patients taking first-generation than those taking second-generation antipsychotic medications. Correlations between working memory and community functioning were stronger for nonsmokers. History of substance use did not moderate working memory impairment.

CONCLUSIONS

Results confirm the working memory impairment in schizophrenia, and indicate smoking status as an important moderator for these deficits. The greater impairment in smokers may reflect added burden of smoking on general health or that patients with greater deficits are more likely to smoke.

Negative symptoms and functioning during the first year after a recent onset of schizophrenia and 8 years later

BACKGROUND

Understanding the longitudinal course of negative symptoms, especially in relationship to functioning, in the early phase of schizophrenia is crucial to developing intervention approaches. The course of negative symptoms and daily functioning was examined over a 1-year period following a recent onset of schizophrenia and at an 8-year follow-up point.

METHODS

The study included 149 recent-onset schizophrenia patients who had a mean age of 23.7 (SD=4.4)years and mean education of 12.9 (SD=2.2)years. Negative symptom (BPRS and SANS) and functional outcome (SCORS) assessments were conducted frequently by trained raters.

RESULTS

After antipsychotic medication stabilization, negative symptoms during the first outpatient year were moderately stable (BPRS ICC=0.64 and SANS ICC=0.66). Despite this overall moderate stability, 24% of patients experienced at least one period of negative symptoms exacerbation. Furthermore, entry level of negative symptoms was significantly associated with poor social functioning (r=-.34, p<.01) and work/school functioning (r=-.25, p<.05) at 12months, and with negative symptoms at the 8-year follow-up (r=.29, p<.05).

DISCUSSION

Early negative symptoms are fairly stable during the first outpatient year, are predictors of daily functioning at 12months, and predict negative symptoms 8years later. Despite the high levels of stability, negative symptoms did fluctuate in a subsample of patients. These findings suggest that negative symptoms may be an important early course target for intervention aimed at promoting recovery.

The relationship of attitudinal beliefs to negative symptoms, neurocognition, and daily functioning in recent-onset schizophrenia

BACKGROUND

In the early course of schizophrenia, premorbid functioning, negative symptoms, and neurocognition have been robustly associated with several domains of daily functioning. Research with chronic schizophrenia patients suggests that attitudinal beliefs may influence daily functioning. However, these relationships have not been examined in recent-onset schizophrenia patients.

METHODS

The sample consisted of recent-onset schizophrenia outpatients (n = 71) who were on average 21.7 (SD = 3.3) years old, had 12.5 (SD = 1.8) years of education, and 5.9 (SD = 6.3) months since psychosis onset. Patients were assessed for premorbid adjustment, positive and negative symptoms, neurocognition, attitudinal beliefs, and daily functioning. Normal controls (n = 20) were screened for psychopathology and demographically matched to the patients.

RESULTS

Comparisons indicated that recent-onset patients had higher levels of dysfunctional attitudes and lower self-efficacy compared to healthy controls (t = 3.35, P < .01; t = -4.1, P < .01, respectively). Dysfunctional attitudes (r = -.34) and self-efficacy (r = .36) were significantly correlated with daily functioning. Negative symptoms were found to mediate the relationship between self-efficacy and daily functioning (Sobel test, P < .01), as well as between dysfunctional attitudes and daily functioning (Sobel test, P < .05). Neurocognition was a significant mediator of the relationship between self-efficacy and daily functioning (Sobel test, P < .05).

DISCUSSION

Early course schizophrenia patients have significantly more dysfunctional attitudes and lower self-efficacy than healthy subjects. Both self-efficacy and dysfunctional attitudes partially contribute to negative symptoms, which in turn influence daily functioning. In addition, self-efficacy partially contributes to neurocognition, which in turn influences daily functioning.

Comparison of the heritability of schizophrenia and endophenotypes in the COGS-1 family study

BACKGROUND

Twin and multiplex family studies have established significant heritability for schizophrenia (SZ), often summarized as 81%. The Consortium on the Genetics of Schizophrenia (COGS-1) family study was designed to deconstruct the genetic architecture of SZ using neurocognitive and neurophysiological endophenotypes, for which heritability estimates ranged from 18% to 50% (mean = 30%). This study assessed the heritability of SZ in these families to determine whether there is a "heritability gap" between the diagnosis and related endophenotypes.

METHODS

Nuclear families (N = 296) with a SZ proband, an unaffected sibling, and both parents (n = 1366 subjects; mean family size = 4.6) underwent comprehensive endophenotype and clinical characterization. The Family Interview for Genetic Studies was administered to all participants and used to obtain convergent psychiatric symptom information for additional first-degree relatives of interviewed subjects (N = 3304 subjects; mean family size = 11.2). Heritability estimates of psychotic disorders were computed for both nuclear and extended families.

RESULTS

The heritability of SZ was 31% and 44% for nuclear and extended families. The inclusion of bipolar disorder increased the heritability to 37% for the nuclear families. When major depression was added, heritability estimates dropped to 34% and 20% for nuclear and extended families, respectively.

CONCLUSIONS

Endophenotypes and psychotic disorders exhibit comparable levels of heritability in the COGS-1 family sample. The ascertainment of families with discordant sibpairs to increase endophenotypic contrast may underestimate diagnostic heritability relative to other studies. However, population-based studies also report significantly lower heritability estimates for SZ. Collectively, these findings support the importance of endophenotype-based strategies and the dimensional view of psychosis.

Social cognition and functional outcome in schizophrenia: The moderating role of cardiac vagal tone

Individuals with schizophrenia face significant challenges in daily functioning, and although social cognition predicts how well patients respond to these challenges, associated physiological mechanisms remain unspecified. The present study draws from polyvagal theory and tested the hypothesis that respiratory sinus arrhythmia (RSA), an established indicator of the capacity to self-regulate and adapt to environmental demands, combines with social cognition to predict functional outcome. Using data from 41 schizophrenia patients and 36 healthy comparison subjects, we replicated group differences in RSA and social cognition and also demonstrated that RSA and social cognition interact to predict how effectively patients manage work and independent living activities. Specifically, RSA did not enhance functional outcomes when social cognition was already strong, but higher levels of RSA enabled effective role functioning when social-cognitive performance was impaired. Jointly, RSA and social cognition accounted for 40% of the variance in outcome success, compared with 21% when evaluating social cognition alone. As polyvagal theory suggests, physiological flexibility and self-regulatory capacity may compensate for poorer social-cognitive skills among schizophrenia patients.

The impact of second-generation antipsychotic adherence on positive and negative symptoms in recent-onset schizophrenia

OBJECTIVE

The aim of the study was to explore the extent to which initial severity of positive or negative symptoms in patients with recent-onset schizophrenia is related to medication nonadherence during the first outpatient year.

METHODS

The study involved 64 first-episode schizophrenia patients treated with the second-generation oral antipsychotic medication, risperidone, for 12 months. Symptoms were evaluated using the SANS and SAPS completed every 3 months. Pearson correlations between medication adherence and symptoms were examined over each 3-month interval during 12 months of follow-through treatment. Possible causality was inferred from cross-lagged panel analyses.

RESULTS

As expected, higher levels of adherence with antipsychotic medication were generally associated with lower levels of concurrent reality distortion (mean of SAPS delusions and hallucinations). Greater adherence during the 3-month baseline interval was generally associated with lower levels of avolition-apathy as well as alogia throughout the first outpatient year. However, medication adherence was not significantly associated with decreases in avolition-apathy or alogia over time. Cross-lagged panel analyses based on correlation coefficients are consistent with a causal relationship between initial medication adherence and lower levels of alogia. A test of mediation confirmed that an indirect path through reality distortion mediated the relationship between medication nonadherence and alogia.

CONCLUSIONS

The associations between greater medication adherence and lower levels of negative symptoms appeared to be accounted for by the relationship of both variables to positive psychotic symptoms. The findings suggest that the impact of second-generation antipsychotic medication on suppression of negative symptoms might be mediated via a reduction in positive symptoms.

Detecting reliable cognitive change in individual patients with the MATRICS Consensus Cognitive Battery

OBJECTIVE

Clinicians often need to evaluate the treatment response of an individual person and to know that observed change is true improvement or worsening beyond usual week-to-week changes. This paper gives clinicians tools to evaluate individual changes on the MATRICS Consensus Cognitive Battery (MCCB). We compare three different approaches: a descriptive analysis of MCCB test-retest performance with no intervention, a reliable change index (RCI) approach controlling for average practice effects, and a regression approach.

METHOD

Data were gathered as part of the MATRICS PASS study (Nuechterlein et al., 2008). A total of 159 people with schizophrenia completed the MCCB at baseline and 4weeks later. Data were analyzed using an RCI and a regression formula establishing confidence intervals.

RESULTS

The RCI and regression approaches agree within one point when baseline values are close to the sample mean. However, the regression approach offers more accurate limits for expected change at the tails of the distribution of baseline scores.

CONCLUSIONS

Although both approaches have their merits, the regression approach provides the most accurate measure of significant change across the full range of scores. As the RCI does not account for regression to the mean and has confidence limits that remain constant across baseline scores, the RCI approach effectively gives narrower confidence limits around an inaccurately predicted average change value. Further, despite the high test-retest reliability of the MCCB, a change in an individual's score must be relatively large to be confident that it is beyond normal month-to-month variation.

Paternal age of schizophrenia probands and endophenotypic differences from unaffected siblings

We evaluated the discrepancy of endophenotypic performance between probands with schizophrenia and unaffected siblings by paternal age at proband birth, a possible marker for de novo mutations. Pairs of schizophrenia probands and unaffected siblings (N=220 pairs) were evaluated on 11 neuropsychological or neurophysiological endophenotypes previously identified as heritable. For each endophenotype, the sibling-minus-proband differences were transformed to standardized scores. Then for each pair, the average discrepancy was calculated from its standardized scores. We tested the hypothesis that the discrepancy is associated with paternal age, controlling for the number of endophenotypes shared between proband and his or her sibling, and proband age, which were both associated with paternal age. The non-significant association between the discrepancy and paternal age was in the opposite direction from the hypothesis. Of the 11 endophenotypes only sensori-motor dexterity was significant, but in the opposite direction. Eight other endophenotypes were also in the opposite direction, but not significant. The results did not support the hypothesized association of increased differences between sibling/proband pairs with greater paternal age. A possible explanation is that the identification of heritable endophenotypes was based on samples for which schizophrenia was attributable to inherited rather than de novo/non-inherited causes.

Developing a Cognitive Training Strategy for First-Episode Schizophrenia: Integrating Bottom-Up and Top-Down Approaches

It is clear that people with schizophrenia typically have cognitive problems in multiple domains as part of their illness. The cognitive deficits are among the main contributors to limitations in their everyday functioning, including their work recovery. Cognitive remediation has been applied successfully to help people with long-term, persistent schizophrenia to improve their cognitive functioning, but it is only beginning to be applied with individuals who have recently had a first episode of psychosis. Several different approaches to cognitive training have been developed. Some approaches emphasize extensive systematic practice with lower-level cognitive processes and building toward higher-level processes ("bottom-up"), while others emphasize greater focus on high-level cognitive processes that normally integrate and organize lower-level processes ("top-down"). Each approach has advantages and disadvantages for a disorder like schizophrenia, with its multiple levels of cognitive dysfunction. In addition, approaches to cognitive remediation differ in the extent to which they systematically facilitate transfer of learning to everyday functioning. We describe in this article the cognitive training approach that was developed for a UCLA study of people with a recent first episode of schizophrenia, a group that may benefit greatly from early intervention that focuses on cognition and recovery of work functioning. This approach integrated bottom-up and top-down computerized cognitive training and incorporated an additional weekly group session to bridge between computerized training and application to everyday work and school functioning.

Contributions of Feature Binding During Encoding and Functional Connectivity of the Medial Temporal Lobe Structures to Episodic Memory Deficits Across the Prodromal and First-Episode Phases of Schizophrenia

Patients with and at risk for psychosis may have difficulty using associative strategies to facilitate episodic memory encoding and recall. In parallel studies, patients with first-episode schizophrenia (n = 27) and high psychosis risk (n = 28) compared with control participants (n = 22 and n = 20, respectively) underwent functional MRI during a remember-know memory task. Psychophysiological interaction analyses, using medial temporal lobe (MTL) structures as regions of interest, were conducted to measure functional connectivity patterns supporting successful episodic memory. During encoding, patients with first-episode schizophrenia demonstrated reduced functional coupling between MTL regions and regions involved in stimulus representations, stimulus selection, and cognitive control. Relative to control participants and patients with high psychosis risk who did not convert to psychosis, patients with high psychosis risk who later converted to psychosis also demonstrated reduced connectivity between MTL regions and auditory-verbal and visual-association regions. These results suggest that episodic memory deficits in schizophrenia are related to inefficient recruitment of cortical connections involved in associative memory formation; such deficits precede the onset of psychosis among those individuals at high clinical risk.

Neural substrates of visual masking by object substitution in schizophrenia

Despite a well-known behavioral finding of visual backward masking impairment in schizophrenia, its underlying neural mechanism remains obscure. This study examined neural correlates of a distinct type of visual backward masking, object substitution masking (OSM), in schizophrenia. Twenty schizophrenia patients and 26 healthy controls completed a 4-Dot OSM task and three functional localizer tasks for the lateral occipital (LO), human motion-sensitive (hMT+), and retinotopic areas in the scanner. In 4-dot masking, subjects detected a target that was followed by a mask consisting of 4 dots that surrounded a target. Stimulus-onset asynchrony (SOA) between target and mask was varied to examine the modulation of masking: (1) within three visual processing areas regions of interest (ROI) (i.e., ROI analysis) and (2) in brain regions outside the three visual processing areas (i.e., whole brain analysis). In the ROI analyses, LO and retinotopic areas showed increased peak amplitude when SOA become longer in both patients and controls. There was also an effect of ROI in that both groups showed higher activation in LO and hMT+ compared with the retinotopic areas. The whole brain analyses revealed a significantly activated area for longer SOAs vs. a short SOA in the occipital cortex in controls only, but the group contrast was not significant. Overall, this study did not find strong evidence for neural abnormalities of OSM in schizophrenia, suggesting that neural substrates of OSM in schizophrenia are not as compromised as those involved in the more common masking methods that rely on disruption of object formation.

A novel, online social cognitive training program for young adults with schizophrenia: A pilot study

BACKGROUND

Pervasive social cognition deficits are evident early in the course of schizophrenia and are directly linked to functional outcome, making them an important target for intervention. Here, we tested the feasibility of use, and initiated the evaluation of efficacy, of a novel, neuroplasticity-based online training program (SocialVille) in young adults with schizophrenia.

METHODS

Schizophrenia patients (n=17) completed 24 hours of online SocialVille game play either from home or at a clinic, over a 6-10 week period. We examined training feasibility, gains on the SocialVille exercises relative to matched healthy controls (n=17), and changes on measures of social cognition, social functioning, global functioning and motivation.

RESULTS

Subjects adhered to training requirements, and rated SocialVille in the medium to high range in satisfaction, enjoyment, and ease of use. Subjects demonstrated significant, large improvements on the speeded SocialVille tasks, and small to moderate improvements on the working memory tasks. Post-training performance on the SocialVille tasks were similar to initial performance of the healthy controls. Subjects also showed improvements on standard measures of social cognition, social functioning, and motivation. No improvements were recorded for emotion recognition indices on the MSCEIT, or on quality of life scales.

CONCLUSION

This study provides an initial proof of concept for online social cognition training in schizophrenia. This form of training demonstrated feasibility and resulted in within-subject gains in social functioning and motivation. This pilot study represents a first step towards validating this training approach; randomized controlled trials, now underway, are designed to confirm and extend these findings.

The early longitudinal course of cognitive deficits in schizophrenia

Cognitive impairment is a core feature of schizophrenia. However, the longitudinal course and pattern of this impairment, and its relationship to functional outcome, are not fully understood. Among the likely factors in the persistence of cognitive deficits in schizophrenia are brain tissue changes over time, which in turn appear to be related to antipsychotic medication adherence. Cognitive deficits are viewed as a core feature of schizophrenia primarily because cognitive deficits clearly exist before the onset of psychosis and can predict illness onset among those at high risk of developing the illness. Additionally, these deficits often persist during symptomatic remissions in patients and are relatively stable across time both in patients and in individuals at risk for schizophrenia. Despite clear evidence that cognitive impairment can predict functional outcome in chronic schizophrenia, results of studies examining this relationship in the early phase of psychosis have been mixed. Recent data, however, strongly suggest that interventions targeting early cognitive deficits may be crucial to the prevention of chronic disability and thus should be a prominent target for therapy. Finally, it is vital to keep schizophrenia patients consistently on their antipsychotic medications. A novel method of examining intracortical myelin volume indicated that the choice of antipsychotic treatment had a differential impact on frontal myelination. These data suggest that long-acting injectable antipsychotic medication may prevent patients from declining further through a combination of better adherence and pharmacokinetics.

Managing disclosure following recent-onset psychosis: utilizing the individual placement and support model

AIMS

Individual Placement and Support is the most defined and evidence-based approach to supported employment for severe mental illness, including recent-onset psychosis. However, there is limited evidence or detailed guidelines informing the management of mental illness disclosure to educators or employers when delivering individual placement and support. In this paper, we describe the initial disclosure preferences of young people with recent-onset psychosis enrolled in individual placement and support and provide guidance for managing disclosure when delivering Individual Placement and Support with this population.

METHODS

Drawing from sites in Melbourne, Australia and Los Angeles, USA, clients' initial disclosure preferences were examined. We describe approaches to providing individual placement and support when no disclosure is permitted compared with when disclosure is permitted, including two illustrative case vignettes.

RESULTS

No disclosure of mental illness or disability was requested by 54-59% of clients; 41-46% of clients permitted partial or complete disclosure. The 'no disclosure' scenario required the individual placement and support worker to provide support 'behind the scenes', whereas when disclosure was permitted, the individual placement and support worker could have contact with instructors/employers and work 'on the front lines'. The case vignettes illustrate how both approaches can lead to successful vocational outcomes.

CONCLUSIONS

We found that Individual Placement and Support can be provided in an educative, flexible, creative and collaborative manner according to client disclosure preferences. We suggest that disclosure preferences do not prevent successful vocational outcomes, although this supposition requires empirical investigation.

Sex differences in familiality effects on neurocognitive performance in schizophrenia

BACKGROUND

Numerous studies have documented that patients with schizophrenia show neurocognitive impairments, which are also heritable in schizophrenia families. In view of these findings, the current investigation tested the hypothesis that neurocognitive performance of schizophrenia probands can predict the neurocognitive performance of their unaffected family members.

METHODS

Participants (n=1967; schizophrenia=369; first-degree relatives=1072; community comparison subjects=526) in the Consortium on the Genetics of Schizophrenia were administered the Penn Computerized Neurocognitive Battery.

RESULTS

Consistent with prior work, probands showed significant neurocognitive impairment, and neurocognitive ability was significantly heritable across domains. On average, unaffected relatives did not differ from community comparison subjects in their neurocognitive performance. However, in six of seven domains, proband scores predicted the performance of their unaffected siblings. Male, but not female, proband performance was predictive of their unaffected relatives' (siblings and mothers) performance, most consistently in face memory and spatial processing.

CONCLUSIONS

Using a novel approach in which individual probands are paired with their respective unaffected relatives within each family, we found that male proband performance predicted both sister and brother performance, an effect that was most powerfully observed for face memory and spatial processing. Results suggest that the familial transmission of sexually dimorphic neurocognitive domains, in which a particular sex tends to show a performance advantage over the other, may not itself be sex specific in schizophrenia families.

Genome-wide linkage analyses of 12 endophenotypes for schizophrenia from the Consortium on the Genetics of Schizophrenia

OBJECTIVE

The Consortium on the Genetics of Schizophrenia has undertaken a large multisite study to characterize 12 neurophysiological and neurocognitive endophenotypic measures as a step toward understanding the complex genetic basis of schizophrenia. The authors previously demonstrated the heritability of these endophenotypes; in the present study, genetic linkage was evaluated.

METHOD

Each family consisted of a proband with schizophrenia, at least one unaffected sibling, and both parents. A total of 1,286 participants from 296 families were genotyped in two phases, and 1,004 individuals were also assessed for the endophenotypes. Linkage analyses of the 6,055 single-nucleotide polymorphisms that were successfully assayed, 5,760 of which were common to both phases, were conducted using both variance components and pedigree-wide regression methods.

RESULTS

Linkage analyses of the 12 endophenotypes collectively identified one region meeting genome-wide significance criteria, with a LOD (log of odds) score of 4.0 on chromosome 3p14 for the antisaccade task, and another region on 1p36 nearly meeting genome-wide significance, with a LOD score of 3.5 for emotion recognition. Chromosomal regions meeting genome-wide suggestive criteria with LOD scores >2.2 were identified for spatial processing (2p25 and 16q23), sensorimotor dexterity (2q24 and 2q32), prepulse inhibition (5p15), the California Verbal Learning Test (8q24), the degraded-stimulus Continuous Performance Test (10q26), face memory (10q26 and 12p12), and the Letter-Number Span (14q23).

CONCLUSIONS

Twelve regions meeting genome-wide significant and suggestive criteria for previously identified heritable, schizophrenia-related endophenotypes were observed, and several genes of potential neurobiological interest were identified. Replication and further genomic studies are needed to assess the biological significance of these results.

Disease and genetic contributions toward local tissue volume disturbances in schizophrenia: a tensor-based morphometry study

Structural brain deficits, especially frontotemporal volume reduction and ventricular enlargement, have been repeatedly reported in patients with schizophrenia. However, it remains unclear whether brain structural deformations may be attributable to disease-related or genetic factors. In this study, the structural magnetic resonance imaging data of 48 adult-onset schizophrenia patients, 65 first-degree nonpsychotic relatives of schizophrenia patients, 27 community comparison (CC) probands, and 73 CC relatives were examined using tensor-based morphometry (TBM) to isolate global and localized differences in tissue volume across the entire brain between groups. We found brain tissue contractions most prominently in frontal and temporal regions and expansions in the putamen/pallidum, and lateral and third ventricles in schizophrenia patients when compared with unrelated CC probands. Results were similar, though less prominent when patients were compared with their nonpsychotic relatives. Structural deformations observed in unaffected patient relatives compared to age-similar CC relatives were suggestive of schizophrenia-related genetic liability and were pronounced in the putamen/pallidum and medial temporal regions. Schizophrenia and genetic liability effects for the putamen/pallidum were confirmed by regions-of-interest analysis. In conclusion, TBM findings complement reports of frontal, temporal, and ventricular dysmorphology in schizophrenia and further indicate that putamen/pallidum enlargements, originally linked mainly with medication exposure in early studies, also reflect a genetic predisposition for schizophrenia. Thus, brain deformation profiles revealed in this study may help to clarify the role of specific genetic or environmental risk factors toward altered brain morphology in schizophrenia.

Statistical shape analysis of the corpus callosum in Schizophrenia

We present a statistical shape-analysis framework for characterizing and comparing morphological variation of the corpus callosum. The midsagittal boundary of the corpus callosum is represented by a closed curve and analyzed using an invariant shape representation. The shape space of callosal curves is endowed with a Riemannian metric. Shape distances are given by the length of shortest paths (geodesics) that are invariant to shape-confounding transformations. The statistical framework enables computation of shape averages and covariances on the shape space in an intrinsic manner (unique to the shape space). The statistical framework makes use of the tangent principal component approach to achieve dimension reduction on the space of corpus callosum shapes. The advantages of this approach are - it is fully automatic, invariant, and avoids the use of landmarks to define shapes. We applied our method to determine the effects of sex, age, schizophrenia and schizophrenia-related genetic liability on callosal shape in a large sample of patients and controls and their first-degree relatives (N=218). Results showed significant age, sex, and schizophrenia effects on both global and local callosal shape structure.

Spectral decomposition of P50 suppression in schizophrenia during concurrent visual processing

Reduced suppression of the auditory P50 event-related potential has long been associated with schizophrenia, but the mechanisms associated with the generation and suppression of the P50 are not well understood. Recent investigations have used spectral decomposition of the electroencephalograph (EEG) signal to gain additional insight into the ongoing electrophysiological activity that may be reflected by the P50 suppression deficit. The present investigation extended this line of study by examining how both a traditional measure of sensory gating and the ongoing EEG from which it is extracted might be modified by the presence of concurrent visual stimulation - perhaps better characterizing gating deficits as they occur in a real-world, complex sensory environment. The EEG was obtained from 18 patients with schizophrenia and 17 healthy control subjects during the P50 suppression paradigm and while identical auditory paired-stimuli were presented concurrently with affectively neutral pictures. Consistent with prior research, schizophrenia patients differed from healthy subjects in gating of power in the theta range; theta activity also was modulated by visual stimulation. In addition, schizophrenia patients showed intact gating but overall increased power in the gamma range, consistent with a model of NMDA receptor dysfunction in the disorder. These results are in line with a model of schizophrenia in which impairments in neural synchrony are related to sensory demands and the processing of multimodal information.

Impact on intracortical myelination trajectory of long acting injection versus oral risperidone in first-episode schizophrenia

CONTEXT

Imaging and post-mortem studies suggest that frontal lobe intracortical myelination is dysregulated in schizophrenia (SZ). Prior MRI studies suggested that early in the treatment of SZ, antipsychotic medications initially increase frontal lobe intracortical myelin (ICM) volume, which subsequently declines prematurely in chronic stages of the disease. Insofar as the trajectory of ICM decline in chronic SZ is due to medication non-adherence or pharmacokinetics, it may be modifiable by long acting injection (LAI) formulations.

OBJECTIVES

Assess the effect of risperidone formulation on the ICM trajectory during a six-month randomized trial of LAI (RLAI) versus oral (RisO) in first-episode SZ subjects.

DESIGN

Two groups of SZ subjects (RLAI, N=9; and RisO, N=13) matched on pre-randomization oral medication exposure were prospectively examined at baseline and 6 months later, along with 12 healthy controls (HCs). Frontal lobe ICM volume was assessed using inversion recovery (IR) and proton density (PD) MRI images. Medication adherence was tracked.

MAIN OUTCOME MEASURE

ICM volume change scores were adjusted for the change in the HCs.

RESULTS

ICM volume increased significantly (p=.005) in RLAI and non-significantly (p=.39) in the RisO groups compared with that of the healthy controls. A differential between-group treatment effect was at a trend level (p=.093). SZ subjects receiving RLAI had better medication adherence and more ICM increases (chi-square p<.05).

CONCLUSIONS

The results suggest that RLAI may promote ICM development in first-episode SZ patients. Better adherence and/or pharmacokinetics provided by LAI may modify the ICM trajectory. In vivo MRI myelination measures can help clarify pharmacotherapeutic mechanisms of action.

Social cognition in schizophrenia, Part 2: 12-month stability and prediction of functional outcome in first-episode patients

This study evaluated the longitudinal stability and functional correlates of social cognition during the early course of schizophrenia. Fifty-five first-episode schizophrenia patients completed baseline and 12-month follow-up assessments of 3 key domains of social cognition (emotional processing, theory of mind, and social/relationship perception), as well as clinical ratings of real-world functioning and symptoms. Scores on all 3 social cognitive tests demonstrated good longitudinal stability with test-retest correlations exceeding .70. Higher baseline and 12-month social cognition scores were both robustly associated with significantly better work functioning, independent living, and social functioning at the 12-month follow-up assessment. Furthermore, cross-lagged panel analyses were consistent with a causal model in which baseline social cognition drove later functional outcome in the domain of work, above and beyond the contribution of symptoms. Social cognitive impairments are relatively stable, functionally relevant features of early schizophrenia. These results extend findings from a companion study, which showed stable impairments across patients in prodromal, first-episode, and chronic phases of illness on the same measures. Social cognitive impairments may serve as useful vulnerability indicators and early clinical intervention targets.

The interaction of electrodermal activity and expressed emotion in predicting symptoms in recent-onset schizophrenia

In the present study, expressed emotion (EE) was assessed among immediate family members of 94 recent-onset schizophrenia patients at initial study entry point, and patients' electrodermal activity (EDA) was measured without the presence of family members at a baseline outpatient stabilization assessment. Psychiatric symptoms were also rated, both at the baseline outpatient test and at 1-year follow-up. Electrodermal activity × expressed emotion interactions were observed at both test points. In each case, the highest levels of negative symptoms were observed among those who exhibited greater EDA and lived in a high-EE environment. These results support the view that the combination of high family EE and sympathetic nervous system arousal confer especially high risk for poor negative symptom outcomes.

Social cognition in schizophrenia, Part 1: performance across phase of illness

Social cognitive impairments are consistently reported in schizophrenia and are associated with functional outcome. We currently know very little about whether these impairments are stable over the course of illness. In the current study, 3 different aspects of social cognition were assessed (emotion processing, Theory of Mind [ToM], and social relationship perception) at 3 distinct developmental phases of illness: prodromal, first episode, and chronic. In this cross-sectional study, participants included 50 individuals with the prodromal risk syndrome for psychosis and 34 demographically comparable controls, 81 first-episode schizophrenia patients and 46 demographically comparable controls, and 53 chronic schizophrenia patients and 47 demographically comparable controls. Outcome measures included total and subtest scores on 3 specialized measures of social cognition: (1) emotion processing assessed with the Mayer-Salovey-Caruso Emotional Intelligence Test, (2) ToM assessed with The Awareness of Social Inference Test, and (3) social relationship perception assessed the Relationships Across Domains Test. Social cognitive performance was impaired across all domains of social cognition and in all clinical samples. Group differences in performance were comparable across phase of illness, with no evidence of progression or improvement. Age had no significant effect on performance for either the clinical or the comparison groups. The findings suggest that social cognition in these 3 domains fits a stable pattern that has outcome and treatment implications. An accompanying article prospectively examines the longitudinal stability of social cognition and prediction of functional outcome in the first-episode sample.