Ethnoracialized group differences in attitudes and knowledge about schizophrenia and willingness to engage in biomarker research: The UBIGR Study

Although there is renewed optimism in biomarker research in schizophrenia, there is also need for greater inclusion of historically underrepresented groups in the research. In the present study, we surveyed 599 African American, 352 American Indian/Alaska Native, and 725 NonHispanic White participants about their attitudes toward research, knowledge and attitudes about schizophrenia, and willingness to engage in biomarker testing. Attitudes toward research were examined using the standardized 7-item Research Attitudes Questionnaire (RAQ) measure. Using structural equation modeling (SEM), we tested our predictive model of the likelihood of willingness to engage in biomarker testing for schizophrenia risk. Members of historically underrepresented groups were less willing to engage in biomarker testing. Overall, attitudes toward research, particularly trust, influenced biomarker testing willingness. These findings suggest that factors influencing willingness to engage in schizophrenia biomarker testing may be modifiable by outreach engagement and education.

Plasma Aβ42/40 and cognitive variability are associated with cognitive function in Black Americans: Findings from the AA-FAIM cohort

Introduction

It is critical to develop more inclusive Alzheimer's disease (AD) research protocols to ensure that historically excluded groups are included in preclinical research and have access to timely diagnosis and treatment. If validated in racialized groups, plasma AD biomarkers and measures of subtle cognitive dysfunction could provide avenues to expand diversity in preclinical AD research. We sought to evaluate the utility of two easily obtained, low-burden disease markers, plasma amyloid beta (Aβ)42/40, and intra-individual cognitive variability (IICV), to predict concurrent and longitudinal cognitive performance in a sample of Black adults.

Methods

Two hundred fifty-seven Black participants enrolled in the African Americans Fighting Alzheimer's in Midlife (AA-FAIM) study underwent at least one cognitive assessment visit; a subset of n = 235 had plasma samples. Baseline IICV was calculated as the standard deviation across participants' z scores on five cognitive measures: Rey Auditory Verbal Learning Test Delayed Recall, Trail Making Test Parts A and B (Trails A and B), and Boston Naming Test. Using mixed effects regression models, we compared concurrent and longitudinal models to baseline plasma Aβ42/40 or IICV by age interactions. PrecivityAD assays quantified baseline plasma Aβ42/40.

Results

IICV was associated with concurrent/baseline performance on several outcomes but did not modify associations between age and cognitive decline. In contrast, plasma Aβ42/40 was unrelated to baseline cognitive performance, but a pattern emerged in interactions with age in longitudinal models of Trails A and B and Rey Auditory Verbal Learning Test total learning trials. Although not significant after correcting for multiple comparisons, low Aβ42/40 was associated with faster cognitive declines over time.

Discussion

Our results are promising as they extend existing findings to an Black American sample using low-cost, low-burden methods that can be implemented outside of a research center, thus supporting efforts for inclusive AD biomarker research.

Social anhedonia and other indicators of risk for schizophrenia: Theory and inquiry

In this commentary, the author traces theoretical contributions that fueled her interest in the role of social/interpersonal striving, relating, and enjoyment in terms of schizophrenia. Social anhedonia is discussed in the context of schizophrenia. The author reviews selective empirical evidence indicating that social anhedonia has a unique role in terms of risk for schizophrenia as well as schizophrenia outcome. Other risk indicators for adult schizophrenia-spectrum outcomes are briefly considered. The author discusses the measurement of social anhedonia across the lifespan and transdiagnostically. Finally, this commentary offers a critique of current strategies for risk calculation.

Racial Differences in Associations of Cognitive Health Status With Happiness, Helplessness, and Hopelessness Among Older Adults: An Exploratory Study

Background

The relationship between healthy and positive aging and dementia and cognitive impairment has received limited attention in the field of aging. Affect impacts cognitive changes and processes, and cognitive impairment is associated with affective comorbidities. The purpose of the study was to examine (a) whether happiness, helplessness, and hopelessness are linked to cognitive health status, and (b) whether these associations differ by race.

Methods

Participants were enrollees in the Wisconsin Alzheimer's Disease Research Center's Clinical Core (ADRC). Average age at baseline was 60.85 (SD = 8.65), 73.70 (SD = 8.02), and 73.80 (SD = 9.59) years for cognitively normal individuals, individuals with MCI, and individuals with dementia, respectively.

Results

In the full sample, chi-square test results revealed associations between Cognitive Health Status (CHS) and (a) happiness, χ2(2) = 6.06, p < 0.05, (b) helplessness, χ2(2) = 6.44, p < 0.05, and (c) hopelessness, χ2(2) = 14.11, p < 0.01.

Conclusion

This study provides support for the association of both positive and negative affect with cognitive health status in middle- to older-aged adults.

The Transdiagnostic Nature of Social Anhedonia: Historical and Current Perspectives

In this chapter, we trace the historical roots of the social anhedonia (SoA) construct to current conceptualizations. We first describe the aspects of SoA that distinguish it from anhedonia in general. We summarize evidence that SoA is a transdiagnostic symptom and risk factor. Although several forms of psychopathology are associated with elevated rates of self-reported SoA, one unresolved issue is whether the processes and mechanisms underlying SoA in one disorder are the same as the processes and mechanisms underlying SoA seen in another disorder. We assert that there may be different causal factors underlying SoA across disorders. Considering both the principles of equifinality and multifinality, we offer an integrative model for social reward processing. This conceptualization considers roles for the following: attention; social cognition, including, but not limited to, social skills; reward learning and valuation; working memory; anticipation, prediction, and remembering; and motivation and effort. We conclude that SoA may be caused by multiple underlying impairments, all of which may serve as targets for intervention. This conceptualization is provided as an impetus for further research in the area.

The characterization of social anhedonia and its correlates in schizophrenia and schizoaffective patients

Although social hedonic capacity is often assessed in clinical settings, its operational definitions have not been evaluated for concurrent validity. One hundred and twenty-five patients with schizophrenia and schizoaffective disorder were classified according to their self-reported social hedonic functioning into three groups on the basis of their total scores on the Anticipatory and Consummatory Interpersonal Pleasure Scale (ACIPS). Participants were assessed before discharge using questionnaires and psychiatric rating scales. Using an empirically based cutoff score, we identified three groups: an intact social hedonic group (WNL), a socially anhedonic group (SA), and a socially hypohedonic group (i.e., those with scores intermediate between normal functioning and aberrantly low functioning, H). The SA patients were significantly different from the two other groups (WNL and H) by their higher severity of psychopathology, lower levels of self-efficacy, and less self-esteem. The SA patients also reported less perceived social support, poorer quality of life, and less subjective recovery. Our findings indicate that social anhedonia is a meaningful target for intervention. Further implications of our findings are discussed.

Assessing social anhedonia in adolescence: The ACIPS-A in a community sample

To date, nearly all self-report measures of anhedonia have been developed for use with adult samples. A valid measure of anhedonia that can be used with adolescents would be useful in order to address key questions about the nature and course of anhedonia during adolescence. This study examined the psychometric properties of an adolescent version of a relatively new measure of social anhedonia, namely, the Anticipatory and Consummatory Interpersonal Pleasure Scale (ACIPS-A). The ACIPS-A was administered to a general, community-derived Spanish adolescent sample of 449 students, including 251 males (55.9%), who ranged in age from 13 to 19 years old. Other measures included the Temporal Experience of Pleasure Scale (TEPS), anhedonia subscales from the Oviedo Schizotypy Assessment Questionnaire (ESQUIZO-Q), and the General Health Questionnaire-12 (GHQ-12). Exploratory factor analysis yielded a four-factor solution (close relationships, casual friendships and relationships, social bonding, and negative affiliation/emancipation). The total ACIPS-A showed excellent internal consistency, with ordinal alpha=0.95. The ACIPS-A total scores were positively correlated with the TEPS-Anticipatory scores (r=0.44, P<0.001) and TEPS-Consummatory scores (r=0.30, P<0.001) but not with total GHQ-12 scores. The ACIPS-A total scores were negatively correlated with social anhedonia subscale scores (r=-0.55) taken from a measure developed for use with adolescents. These results suggest that the ACIPS-A is a valid measure for use with non-clinical adolescents and is likely to prove useful for screening purposes.

Thought disorder in mid-childhood as a predictor of adulthood diagnostic outcome: findings from the New York High-Risk Project

BACKGROUND

Thought disorder has been proposed as an indicator of schizotypy, which is considered to be necessary but not sufficient for the development of schizophrenia. It is unclear whether thought disorder is an indicator of susceptibility (i.e. an endophenotype) for schizophrenia. The goal of the present study was to elucidate the role of thought disorder in relation to schizotypy by examining its presence in high-risk individuals during mid-childhood. Method The sample consisted of 265 subjects drawn from the New York High-Risk Project. Individuals at high risk for schizophrenia (i.e. offspring of parents with schizophrenia) were compared with individuals at low risk for schizophrenia (i.e. offspring of parents with affective disorder or offspring of psychiatrically normal parents). Videotaped interviews were rated for thought disorder using the Scale for the Assessment of Thought, Language, and Communication (TLC). The same subjects were administered diagnostic interviews in late adolescence/early adulthood.

RESULTS

Although positive thought disorder was equally present in subjects with affective and non-affective psychoses, negative thought disorder (namely, poverty of speech and poverty of content of speech) was elevated only in subjects with schizophrenia-related psychosis. Logistic regression analyses revealed that negative thought disorder added to the prediction of schizophrenia-related psychosis outcomes over and above positive thought disorder.

CONCLUSIONS

These findings suggest that negative thought disorder may have a specific association with schizotypy, rather than a more general association with psychosis. The findings also support consideration of negative thought disorder as an endophenotypic indicator of a schizophrenia diathesis.

Theory of Mind and psychometric schizotypy

The extent to which Theory of Mind impairments are a trait associated with schizotypy is unclear. To date, findings have been mixed. We compared two groups of psychometrically identified schizotypes, namely, those characterized by positive schizotypy (perceptual aberrations and magical ideation; n=36) and those characterized by negative schizotypy (social anhedonia; n=30) to a low schizotypy comparison group (n=68) in terms of their Theory of Mind performance. Theory of Mind was assessed in two ways: a composite Hinting Task and the Reading the Mind in the Eyes Test. The groups were also compared in terms of their self-reported levels of referential thinking. Our results indicate that individuals characterized by positive schizotypy show Theory of Mind deficits, as measured by the Hinting Task. The three groups did not differ in terms of the Eyes Test. Referential thinking was significantly associated with the Eyes Test but not the Hinting Task. Overall these findings suggest that different aspects of schizotypy are associated differentially with Theory of Mind deficits. The results also provide further rationale for the inclusion of multiple tasks when attempting to study multifaceted constructs such as Theory of Mind.

Schizotypy and altered digit ratios: a second look

Alterations in the ratio between the 2nd and 4th finger digits have been posited as a potential indicator of increased liability for neurodevelopmental disorders such as autism and schizophrenia. We compared digit ratios in two groups of psychometrically-identified schizotypes, namely, those characterized by positive schizotypy (perceptual aberrations and magical ideation; n=76) and those characterized by negative schizotypy (social anhedonia; n=64), to a control group (n=110). The groups were also compared in terms of their performance on a measure of Theory of Mind, namely, the Reading the Mind in the Eyes Test (RMET) and trait affect, as measured by the PANAS. Our results indicate that neither negative schizotypy nor positive schizotypy is associated with altered digit ratios. Similarly, the groups showed no significant differences on the RMET. However, we observed a small but significant inverse association between Theory of Mind performance and negative affect. The findings are considered in light of the extant literature. These results call into question the viability of altered digit ratios to serve as an indicator of increased risk for schizophrenia-spectrum disorders.

Attentional deficits in cocaine-dependent patients: converging behavioral and electrophysiological evidence

Although there are several reports of patients with cocaine dependence displaying cognitive deficits, the nature of their information processing deficits is not well characterized. In the present study, the attentional performance of cocaine-dependent patients (n=14) was examined and compared with that of healthy control individuals (n=15). Attention was assessed using an auditory oddball event-related task as well as the Continuous Performance Test (CPT, Identical Pairs version). The cocaine-dependent group displayed P300 amplitude reduction compared to controls. The group difference in P300 response latency did not reach significance. On the CPT, the cocaine-dependent patients displayed significantly poorer discriminability and greater errors of commission than the controls. There was a positive correlation between performance on the oddball event-related task and performance on the CPT. This investigation provides converging behavioral and electrophysiological evidence of attentional deficits in cocaine-dependent patients.

Temporal stability of saccadic task performance in schizophrenia and bipolar patients

BACKGROUND

Identifying endophenotypes of schizophrenia will assist in the identification of individuals who are at heightened risk for the disorder. Investigators have proposed antisaccade task deficits as an endophenotypic marker of schizophrenia. However, the diagnostic specificity and the temporal stability of the task deficit are unresolved issues. To date, there are few published reports of test-retest stability of antisaccade task performance in psychiatric patients.

METHOD

Twenty-three schizophrenia out-patients and 10 bipolar out-patients were administered two saccadic (antisaccade and refixation) tasks at two separate assessments, with an average test retest interval of 33 months.

RESULTS

The schizophrenia patients displayed high test-retest reliabilities of antisaccade task accuracy, despite changes in medication and clinical status. Additionally, the schizophrenia group's saccadic reaction times for antisaccade correct responses and task errors were moderately stable over time. In contrast, the bipolar patients did not show temporal stability in their antisaccade task accuracy or in their response latencies to either correct or incorrect antisaccade responses.

CONCLUSIONS

The results are supportive of the trait-like characteristics of antisaccade task deficits in schizophrenia patients. These findings also suggest that antisaccade task deficits may serve as an endophenotypic marker of schizophrenia.

Evidence of schizophrenia patients' reduced perceptual biases in response to emotion chimera

The goal of the study was to determine whether dextral individuals with schizophrenia display atypical perceptual biases in response to faces in general, or whether they display atypical perceptual biases in response to emotional facial cues. To this end, we assessed perceptual processing in schizophrenia patients with four types of free-vision chimeric stimuli. Perceptual biases were evaluated in 45 schizophrenia patients and in 46 controls using two face (emotion, gender) tasks and two nonface (dots, gradients) tasks. In response to the emotion chimera, the patients with schizophrenia displayed a reduced left perceptual bias. The two groups did not differ significantly in their response to the gender chimera or to the two nonface chimera. These findings are consistent with the assertion that schizophrenia patients have impaired emotional perception. In the discussion we consider possible reasons for schizophrenia patients' difficulty comprehending emotional facial stimuli. We suggest that schizophrenia patients' reduced perceptual bias in response to the emotion chimera reflects a hypothesized affective information-processing deficit.

Cognitive slippage in schizotypic individuals

The Miers and Raulin Cognitive Slippage Scale was used to assess subtle thought disorder, and the Wisconsin Card Sorting Test (WCST) was used to assess cognitive performance in deviantly high scorers on the Perceptual Aberration and Magical Ideation Scales (N = 63), high scorers on the revised Social Anhedonia Scale (N = 62), and in control subjects (N = 83). Results indicate that schizotypic individuals are more likely to report greater cognitive slippage and less likely to achieve as many WCST categories as controls. Individuals with both positive and negative symptoms of schizotypy reported higher levels of cognitive slippage than those individuals reporting only negative schizotypy. Additionally, the results confirm the presence of an especially high-risk group of psychosis-prone individuals, namely, those individuals with deviant scores on the revised Social Anhedonia Scale who possess additional indicators of schizotypy.

The association between antisaccade task and working memory task performance in schizophrenia and bipolar disorder

To date, the research literature has yielded conflicting reports regarding the specificity of antisaccade deficits to schizophrenia. We sought to examine antisaccade and working memory task performance in schizophrenia patients and bipolar patients, as well as to examine the relationship between the two tasks in both patient populations. Thirty-four schizophrenia patients, 20 bipolar patients, and 30 nonpatient controls were administered saccadic inhibition (antisaccade), working memory, and sensorimotor tasks. Compared with the controls, the schizophrenia patients displayed both antisaccade deficits and working memory deficits. In contrast, the bipolar patients produced significantly more errors on the antisaccade task than the controls, though the bipolar group performed similarly to the control group on the working memory task. Mediational analyses demonstrated that working memory partially mediates the relationship between patients' diagnostic group status and antisaccade task performance; working memory performance contributed uniquely to the prediction of antisaccade task performance in the two patient groups. Antisaccade deficits do not appear specific to schizophrenia. The results suggest that in schizophrenia, working memory and antisaccade tasks are tapping similar cognitive processes, whereas in bipolar patients the processes underlying antisaccade and working memory performance are disparate.

Fixation stability in schizophrenia, bipolar, and control subjects

A few investigators have suggested that visual fixation abnormalities may serve as an endophenotype of liability for schizophrenia. However, the data are equivocal. Conflicting reports regarding the specificity of fixation deficits to schizophrenia may be attributable to methodological differences. Thirty-four schizophrenia patients, 20 bipolar patients, and 30 non-patient controls were presented targets for central fixation. Fixation was scored in terms of frequency of saccades as well as qualitative ratings. Analysis of variance on the number of saccades produced during fixation revealed that the three groups did not differ. Similarly, we observed that the schizophrenia patients did not differ from either bipolar patients or controls in terms of ratings of fixation quality. It appears that schizophrenia patients are not characterized by poor visual fixation. The findings are discussed in terms of the viability of visual fixation as a marker of schizophrenic diathesis, as well as possible implications for the analysis of schizophrenia patients' visual search performance.

Smooth pursuit eye tracking and visual fixation in psychosis-prone individuals

Subjects identified by Perceptual Aberration-Magical Ideation (Per-Mag) scores (n=97), Social Anhedonia (SocAnh) scores (n=45), and Physical Anhedonia (PhysAnh) scores (n=31) as well as normal controls (n=94), underwent psychophysiological and clinical assessment. This is the first published investigation of pursuit system functioning in three groups of questionnaire-identified at-risk individuals. Pursuit during a simple non-monitor tracking task was measured using root-mean-square error (RMSE) scores and pursuit gain scores. Fixation performance was measured in terms of number of saccades away from the central fixation point. The at-risk subjects were more likely to display aberrant smooth pursuit tracking than controls, though there were no significant differences between the at-risk subjects endorsing items relevant to positive-symptom schizotypy and those endorsing items pertaining to negative-symptom schizotypy. The groups did not differ significantly in their visual fixation performance. Participants were also evaluated for the presence of Axis I symptomatology and psychotic-like experiences. Neither the experimental subjects nor the control subjects displayed a significant association between ocular motor performance and psychotic-like experiences. These findings are consistent with prior evidence that pursuit tracking is a trait characteristic, independent of clinical status.

Working memory and Wisconsin Card Sorting Test performance in schizotypic individuals: a replication and extension

The present study examined spatial working memory and Wisconsin Card Sorting Test (WCST) performance in psychosis-prone individuals, either those with extremely high scores on the Social Anhedonia Scale (SocAnh; n = 49) or deviant scores on the Perceptual Aberration-Magical Ideation Scales (Per-Mag; n = 66). Sixty-three individuals with normal scores on the Chapman Psychosis-Proneness Scales served as control subjects. In order to evaluate working memory performance, participants were administered three tasks, namely, sensorimotor, degraded stimulus, and delayed-response tasks. Although the SocAnh and Per-Mag groups displayed poorer performance than control subjects on the working memory task, they did not differ significantly from each other. The SocAnh group exhibited slower reaction times on the working memory task compared to the control group. The groups did not differ in their performance on sensorimotor or degraded stimulus control tasks. Both psychosis-prone groups differed significantly from control subjects in terms of their WCST performance. Working memory performance was inversely associated with the number of perseverative errors (r = -0.17) and the number of trials to complete the first category on the WCST (r= -0.15). These findings extend the literature by indicating that some psychosis-prone individuals with social-interpersonal schizotypal deficits also display subtle spatial working memory impairments.

Wisconsin Card Sorting Test deficits in schizotypic individuals

The present study investigates executive functioning in schizotypic college students and control subjects using the Wisconsin Card Sorting Test (WCST). Inhibitory control and working memory, two aspects of executive functioning, were examined in deviantly high scorers on the Perceptual Aberration and Magical Ideation Scales (n=97), high scorers on the revised Social Anhedonia Scale (n=58), and in control subjects (n=104). The schizotypic groups displayed significantly more perseverative errors and achieved fewer categories than the control group. The two schizotypic groups did not differ from each other. We identified a subset of schizotypic individuals who also produced clinically deviant WCST profiles. The findings support the hypothesis that executive function deficits may precede the onset of schizophrenia and related illnesses.

Smooth pursuit and saccadic eye movement performance in a prefrontal leukotomy patient

The authors wished to examine the role of the prefrontal cortex in oculomotor performance. They assessed smooth pursuit and saccadic performance in a patient with schizophrenia who had undergone a bilateral prefrontal leukotomy. Her performance on neuropsychological test measures sensitive to frontal lobe functioning were also examined. Against a background of intact intellectual and neurological functioning, the patient displayed a dissociation in premotor and prefrontal functioning. Smooth pursuit performance was within normal limits, as were the patient's finger tapping scores. In contrast, the patient performed poorly on the Wisconsin Card Sorting Test, and verbal and design fluency tasks. Similarly, her performance on the antisaccade task was markedly deviant. Despite advanced age and a frontal leukotomy, this patient with schizophrenia displayed intact smooth pursuit, indicating that the frontal cortex is not necessary for normal smooth pursuit performance.

Perceptual biases in psychosis-prone individuals

College students screened for psychosis-proneness using the Chapman scales were compared on 4 free-vision tasks that typically yield left-spatial-field biases. The tasks included 2 chimeric face tests, consisting of happy/neutral faces and male/female faces, and 2 nonface tasks, consisting of pairs of dot-filled or gradient-filled rectangles. Participants endorsing perceptual aberration items, magical ideation items, or both (n = 98) and control participants (n = 112) were left-biased on all tasks but gradients and were most biased on emotion faces; in contrast, i.e., social anhedonia participants (n = 40) displayed very little or no left-field biases. For all groups, task intercorrelations were greatest between the 2 face tasks and between the 2 nonface tasks. These findings suggest patterns of atypical perceptual asymmetry in psychosis-prone individuals.

Perceptual biases in psychosis-prone individuals

College students screened for psychosis-proneness using the Chapman scales were compared on 4 free-vision tasks that typically yield left-spatial-field biases. The tasks included 2 chimeric face tests, consisting of happy/neutral faces and male/female faces, and 2 nonface tasks, consisting of pairs of dot-filled or gradient-filled rectangles. Participants endorsing perceptual aberration items, magical ideation items, or both (n = 98) and control participants (n = 112) were left-biased on all tasks but gradients and were most biased on emotion faces; in contrast, i.e., social anhedonia participants (n = 40) displayed very little or no left-field biases. For all groups, task intercorrelations were greatest between the 2 face tasks and between the 2 nonface tasks. These findings suggest patterns of atypical perceptual asymmetry in psychosis-prone individuals.

Antisaccade task performance in questionnaire-identified schizotypes

Individuals who scored high on Perceptual Aberration-Magical Ideation Scales (Per-Mag; n = 90), the Social Anhedonia Scale (SocAnh; n = 39), and control participants (n = 89) were administered saccadic refixation (prosaccade) and saccadic suppression (antisaccade) tasks. Eye movements were scored in terms of error rates and latency. None of the groups differed in terms of their performance on the prosaccade task. Both the Per-Mag (p < 0.01) and SocAnh (p < 0.05) groups exceeded the controls in terms of mean antisaccade errors. The high-risk groups did not differ from each other. Eighteen of the Per-Mag individuals and 10 of the SocAnh individuals displayed deviant antisaccade performance. These findings are particularly interesting in light of suggestive evidence that antisaccade task deficits may serve as a marker of susceptibility to schizophrenia. It is hypothesized that the individuals who scored aberrantly on the Chapman scales and displayed antisaccade performance deficits are most likely to be at risk for the development of psychosis.

Nailfold capillary plexus visibility in relation to schizotypy

High plexus visibility is a potential biological marker of a schizophrenia diathesis. Plexus visibility was assessed in college students endorsing schizotypal traits and normal controls. Twenty-two (nearly 14%) of the 160 schizotypal individuals displayed the trait. None of the controls (n = 99) showed high plexus visibility. These results provide supportive evidence for an association between increased plexus visibility and schizotypy.

Temporal stability of smooth-pursuit eye tracking in first-episode psychosis

We evaluated the temporal stability of smooth-pursuit eye tracking in 38 schizophrenic, 42 nonschizophrenic psychotic (bipolar, depressive, paranoid psychotic, and schizophreniform), and 49 normal subjects. Pursuit performance was evaluated on two testing occasions separated by approximately 9.5 months. Retest reliability coefficients of root mean square (RMS) error scores for schizophrenic and normal subjects were .68 and .57, respectively. The reliability coefficients of RMS error scores for the nonschizophrenic psychotic patients ranged from .44 to .51. Level of psychological functioning was not significantly related to tracking performance, and most patients' pursuit performance remained stable despite changes in medication and clinical status. These results support the hypothesis that eye tracking dysfunction is a trait characteristic that can serve as a vulnerability indicator of schizophrenia.

The association between lithium carbonate and smooth pursuit eye tracking among first-episode patients with psychotic affective disorders

The association between treatment with lithium carbonate and smooth pursuit eye tracking performance was investigated in first-episode patients with psychotic affective disorders. The horizontal pursuit performance of patients with major depression and bipolar disorder who were receiving lithium carbonate was contrasted with that of patients not receiving lithium carbonate. In addition, the accuracy and quality of pursuit eye tracking was examined in bipolar patients whose lithium status changed from the time of initial testing to the time of retest 10 months later. For the combined group of depressed and bipolar patients, treatment with lithium carbonate was not associated with worse pursuit performance. Bipolar disordered patients on lithium did not differ in tracking proficiency from those not on lithium; bipolar patients whose lithium status changed from intake to retest also did not display a significant change in pursuit performance.