Convergent validity and neuropsychological correlates of the schedule for the assessment of negative symptoms (SANS) attention subscale.

Cognitive deficits have come to be viewed as a hallmark feature of schizophrenic illness. Although laboratory based assessment of patients' cognitive deficits has been well investigated, few studies to date have examined the utility of clinical ratings of cognitive symptoms using the Schedule for the Assessment of Negative Symptoms (SANS) attention subscale. In this report, we examined the convergence between clinical ratings of cognitive impairment using the SANS attention subscale and performance on a variety of neurocognitive tests designed to measure attentional impairment, as well as other cognitive constructs such as working memory and executive functioning. A total of 56 acute schizophrenic inpatients were clinically rated with the SANS and completed the Continuous Performance Test, Digit Span Distraction Test, Wisconsin Card Sorting Task, and the Trailmaking Test. A series of correlational and regression analyses were conducted to test the concurrent and discriminant validity of the SANS attention subscale. Performance measures of attention, but not working memory or executive functioning, were significantly correlated with and moderately predicted the severity of SANS rated inattention. Additionally, the attention subscale was discriminated from the other SANS negative symptom subscales in predicting a laboratory measure of attentional functioning. The SANS attention subscale demonstrated both concurrent and discriminant validity. These data indicate that attentional dysfunction in schizophrenia can be meaningfully rated and interpreted using the SANS.

The convergence of neuropsychological testing and clinical ratings of cognitive impairment in patients with schizophrenia.

This study examined the relationship between clinical rating of cognitive symptoms and performance on neuropsychological tests in acute and chronic samples of patients with schizophrenia. Two separate studies examined patients who varied widely in their lifetime functional outcome, including 263 elderly poor-outcome inpatients and 20 acutely admitted patients. In the first study, six cognitive performance measures were collected, and in the second study, five different measures were collected. Correlations with different symptom models of cognitive and negative symptoms were examined. In both samples, cognitive symptoms were never more highly correlated with cognitive test performance than with negative symptoms. When cognitive and negative symptom ratings were combined, they never accounted for as much as half of the variance in performance on the cognitive tests in both samples. These data suggest that clinical assessment of symptoms is not a viable alternative to neuropsychological testing to obtain information about cognitive functioning in schizophrenia. These results may also be specific to the clinical rating scale used, the Positive and Negative Syndrome Scale (PANSS).

Practice-related improvement in information processing with novel antipsychotic treatment.

BACKGROUND: Attentional deficits are prominent in schizophrenia, and skill learning is impaired. Novel antipsychotic treatment has been reported to improve certain cognitive skills in schizophrenic patients, but no information is yet available about the effect of newer medications on skill learning. METHODS: Clinically stable patients with schizophrenia (n=16) and chronically hospitalized inpatients (n=8) were recruited while receiving conventional antipsychotic treatment. Subjects were tested at baseline on a visual continuous performance test (CPT), performed alone and simultaneously with an auditory CPT. Normal controls (n=8) were also tested at baseline. The inpatients and half of the outpatients were switched to treatment with risperidone. All patients then performed the visual CPT on a daily basis and performed the dual tasks once per week, for 4weeks. RESULTS: Patients who remained on conventional medications did not improve in their performance despite the extensive practice on the test. Both chronic and stable patients receiving risperidone treatment manifested a statistically significant (P<0.05) improvement from baseline on both single and dual-task visual CPT. Stable outpatients performed significantly better at the end of the protocol than the normal controls performance at baseline (P<0.05). IMPLICATIONS: These results suggest that practice-related improvements in the performance of information processing tests are enhanced by novel antipsychotic medications. Although the specific biological mechanism of this effect is not yet known, the results may suggest that use of newer medications will enhance skill development and perhaps facilitate rehabilitation of patients with schizophrenia.

Neurocognitive functioning in recently abstinent, cocaine-abusing schizophrenic patients.

PURPOSE: This report examined a broad range of cognitive functioning in a group of recently abstinent, cocaine-abusing schizophrenic patients (CA + SZ). METHODS: Measures of selective and sustained attention, learning and memory, and executive functioning were administered to CA + SZ patients within 72 h of last cocaine use. A comparison group of non-substance-abusing schizophrenic patients (SZ) presenting for inpatient psychiatric treatment were also examined in an identical time frame. We hypothesized that the neurobiological impact of cocaine abuse and acute abstinence would cause CA + SZ to manifest deficits in all domains of cognitive functioning relative to non-abusing SZ patients. RESULTS: Results revealed that CA + SZ displayed significant memory impairment relative to their non-abuser SZ counterparts. No group differences, however, were detected on any other neurocognitive measure. CA + SZ were able to selectively process digit strings during the presence and absence of distracting stimuli, sustain attention, and perform executive functions at performance levels equal to their non-abuser SZ counterparts. IMPLICATIONS: These results are consistent with many past studies that have found CA + SZ patients to manifest memory impairment but have relatively well preserved functioning in other cognitive domains. The results are discussed in terms of the biological concomitants of cocaine abuse and acute abstinence in schizophrenia.

Learning and memory impairment in cocaine-dependent and comorbid schizophrenic patients.

Impairments in verbal learning and memory functioning have been found to be cardinal features among individuals with schizophrenia as well as among non-schizophrenic cocaine abusers. Cognitive deficits in these areas, moreover, have been associated with poor treatment response and short-term outcome. Little is known, however, about the acute effects of cocaine abuse on schizophrenic patients' learning and memory functioning. Consequently, a potentially reversible and treatable source of cognitive impairment has been virtually ignored. The present study examined the extent of verbal learning and memory impairment in a group of cocaine-dependent schizophrenic patients (n=42) and a group of non-schizophrenic cocaine-dependent patients (n=21) within 72 h of the last cocaine use using the California Verbal Learning Test (CVLT). Schizophrenic patients (n=34) without any substance-use disorders were also tested in an identical time frame and served as a comparison group. Results revealed that all groups demonstrated significant learning and memory impairment relative to CVLT published age and gender corrected norms. Both cocaine-dependent and non-substance abusing schizophrenic groups presented a very similar pattern of impaired learning and recall performance across all CVLT task domains. Comorbid patients, in contrast, presented with marked deficits in their ability to learn and recall verbal information relative to either schizophrenic or cocaine-only groups. Moreover, the cocaine-abusing schizophrenic patients showed significant forgetfulness of the information that they did acquire during delayed recall conditions. The performance deficits exhibited by cocaine-abusing schizophrenic patients differed not only in relative severity of impairment, but also qualitatively in their increased rates of forgetfulness of acquired information. These results are interpreted in terms of the neurobiological substrates of learning and memory and the neurobiological impact of cocaine on schizophrenic patients' cognition during the early phase of inpatient hospitalization. These results suggest that comorbid patients should be targeted for specialized remediation efforts at the beginning phases of inpatient treatment.

Social support and psychopathology in homeless patients presenting for emergency psychiatric treatment.

We compared homeless to domiciled psychiatric patients' symptomatology and perceived level of social support (PSS) within hours of psychiatric emergency service (PES) arrival. Homeless patients experienced less PSS and more negative symptoms, but not more psychosis, than their domiciled counterparts. Domiciled patients' PSS was highly related to their clinical presentation: less support predicted increased psychopathology. Homeless patients' clinical symptoms, although as common and severe, were unassociated with PSS. These findings suggest that homeless psychiatric patients may be less reactive to positive environmental influences like social support and manifest more severe and refractory symptoms than domiciled patients presenting for emergency treatment.

Symptomatic overlap of cocaine intoxication and acute schizophrenia at emergency presentation.

Cocaine intoxication and acute abstinence alter brain dopaminergic functioning, resulting in behavioral changes closely mimicking the positive and negative symptoms of schizophrenia. In emergency room settings, recent cocaine abuse can be mistaken for schizophrenia and may cause inappropriate diagnosis and in some instances medical mismanagement. Schizophrenia patients presenting with recent cocaine abuse may also present with significant diagnostic and treatment dilemmas. This study attempts to distinguish between cocaine and schizophrenic psychosis by examining patients who present with both recent cocaine abuse and acute schizophrenia (CA+SZ), cocaine intoxication without schizophrenic illness (CA), and acute schizophrenia with no comorbid substance abuse (SZ) within the first 24 hours after arrival at the Bellevue psychiatric emergency service. Clinical assessment included the Brief Psychiatric Rating Scale, the Schedule for the Assessment of Positive Symptoms, and the Schedule for the Assessment of Negative Symptoms. Both cocaine abusing groups were required to have positive urine toxicology screens for inclusion in the study. Multivariate analysis of variance showed the CA+SZ patients present with a clinical profile that overlaps with CA patients on mood and negative symptom dimensions and overlaps with SZ patients on most positive symptoms. CA+SZ patients differed from both groups, however, by presenting with significantly more hallucinatory experiences than cocaine abusing or schizophrenia patient counterparts. Despite considerable overlap, each group of patients presented with a discernible cross-sectional symptom pattern.

Attentional and clinical neuroleptic response in schizophrenia: a study with the continuous performance test.

Past research has confirmed the importance of vigilance deficits in schizophrenia. The present investigation examined the temporal relationship between treatment response of acute schizophrenic inpatients' (n = 13) psychopathology and their vigilance performance, using the Continuous Performance Test, at four time points over the course of an acute hospitalisation: at medication-free baseline and then weekly for 21 days after the initiation of neuroleptic treatment. A comparison group of stable schizophrenic outpatients (n = 12) receiving neuroleptics at all assessments were also tested during the same time period. For the acute group we found a significant improvement in both vigilance and symptoms over the course of neuroleptic treatment and the extent of improvement in vigilance performance was correlated with improvements in symptomatology. The control patients exhibited no CPT improvement or symptomatic changes. Because vigilance deficits correlate with poor outcome in schizophrenia, these data suggest that the medication-related changes in cognitive performance early in the course of neuroleptic treatment may provide clues to the expected course of illness in acute patients.

Clinical effects of recent cocaine use on patients with acute schizophrenia.

OBJECTIVE: Dopamine function has been hypothesized to be involved in both producing schizophrenic symptoms and mediating cocaine's reinforcing properties. As a result, cocaine abuse in schizophrenic patients may be seen as a natural experiment that may alter the phenomenology and neurobiology of schizophrenia. This report concerns the clinical effects of cocaine abuse and cessation in schizophrenic patients at two times: when patients presented to the psychiatric emergency service and again after 4 weeks of hospitalization. METHOD: The subjects were 15 cocaine-abusing and 22 cocaine-abstaining schizophrenic patients. Diagnostic assessments were performed with the Structured Clinical Interview for DSM-III-R--Patient Version, which uses DSM-III-R criteria. All of the patients were assessed at both times with the Brief Psychiatric Rating Scale, the Scale for the Assessment of Positive Symptoms, and the Scale for the Assessment of Negative Symptoms. RESULTS: Cocaine-abusing schizophrenic patients showed fewer negative signs and more anxiety/depression at the hospital-admission assessment than their nonabusing counterparts. At retest, no group differences were detected in patients' negative signs or mood symptoms. Severity of positive symptoms was equal at both testing sessions. CONCLUSIONS: The significant difference in negative signs and mood symptoms at admission assessment was attributed to the neurobiological impact of cocaine. The role of psychostimulants in schizophrenic patients is discussed.

Attentional predictors of clinical change during neuroleptic treatment in schizophrenia.

Improvement in auditory selective attention performance was examined in acute schizophrenic inpatients (n = 13) both off and on medication using the digit span distraction task. Subjects were tested at drug-free baseline and weekly for three weeks during treatment with haloperidol. Improvements in distractability preceded and predicted clinical improvements. A control group of stable schizophrenic outpatients (n = 12) medicated at all testing intervals were examined during the same time period. No significant clinical or attentional changes were found in the control group over the four testing intervals. These results suggest that specific types of attentional functions are intrinsically related to the biological processes affected by neuroleptic treatment and lend preliminary support to the contention that schizophrenic symptoms are mediated by attentional impairment.

The need to integrate neuropsychological and experimental schizophrenia research.

Although the experimental and the neuropsychological approaches to the study of schizophrenic cognition have coexisted for many years, they remain detached, with virtually independent methods and literatures. The result has been a needless duplication of work and effort. In this article we review the emergence and representative research of each approach, examine model integrative studies, and suggest ways in which the two approaches can be better integrated to generate comprehensive cognitive schizophrenia theories and research.

Visual controlled information processing resources and formal thought disorder in schizophrenia and mania.

Visual selective attentional performance under low and high processing load conditions was examined in patients with schizophrenia (n = 20), or bipolar affective disorder-manic type (n = 21) and a group of normal control subjects (n = 18). Although schizophrenic patients demonstrated significantly more impaired cognitive performance than normal controls, bipolar patients were found to be as deviant as the schizophrenic patients on almost all of the performance variables. Positive thought disorder under high processing load demands was moderately correlated with schizophrenic patients' response processing ability. In contrast, negative thought disorder ratings were found to be moderately associated with reaction time performance during high processing demands for both patient groups. These findings are discussed with regard to the relationship between selective attention, visual-motor controlled information processing deficits, and thought disorder in psychosis.

Empirical assessment of the factorial structure of clinical symptoms in schizophrenic patients: formal thought disorder.

Male schizophrenic patients (n = 142) were examined with a clinical assessment of their language dysfunctions with the Scale for the Assessment of Thought, Language, and Communication (TLC). Confirmatory factor analyses were conducted to test the relative fit of several differential theoretical models of the factorial structure of thought disorders. The models examined were positive-negative thought disorder, a three-factor model based on the results of an earlier exploratory factor analysis, and a simpler verbal productivity-disconnection model that can be extracted from other exploratory analyses and empirical studies. The positive-negative thought disorder model failed to fit the data, while the three-factor model fit the data, but no better than the simpler verbal productivity-disconnection model.

Continuous performance tests in schizophrenic patients: stimulus and medication effects on performance.

Medicated (n = 17) and unmedicated (n = 17) schizophrenic patients were compared to a normal control group (n = 19) on their performance on auditory and visual versions of the Continuous Performance Test (CPT). Within each stimulus modality, performance was examined on lexical and nonlexical target stimuli. Neuromotor competence was assessed on the basis of motor speed and proficiency. Normal subjects made fewer errors of all types than schizophrenic patients. Unmedicated patients made significantly more errors on nonlexical stimuli than medicated patients, with medication status found not to be associated with stimulus modality effects. Motor proficiency was associated with CPT performance in the medicated patients, but not the unmedicated ones, although this difference in correlations did not account for the group differences between these patients. The authors discuss the implications of these data for the type of cognitive and attentional functions that are affected by medication in schizophrenia.

Development and preliminary validation of a questionnaire assessment of expressed emotion.

A questionnaire for management of expressed emotion was constructed. It consisted of two scales, criticism and emotional overinvolvement. The questionnaire and the Camberwell Family Interview were then administered to relatives of schizophrenics and preliminary assessments of scale reliabilities and concurrent validities were done. Both questionnaire scales were reliable. With respect to validity the criticism scale correctly classified 88% of the subjects relative to the criticism scale of the interview. The emotional overinvolvement scale was less satisfactory (67%) but still assisted in classification of over-all expressed emotion. Expressed emotion, classification by the questionnaire, correctly identified 84% of the subjects with respect to the interview.

Linguistic and cognitive failures in schizophrenia. A multivariate analysis.

Schizophrenic (N = 38), manic (N = 30), and normal (N = 25) subjects were examined with laboratory tasks measuring serial recall and encoding, distractibility, and reality monitoring. In addition, the psychiatric patients were examined with three measures of verbal communication disorder, including positive thought disorder, negative thought disorder, and frequency of reference failures. It was found that positive thought disorder and reference failures in schizophrenics were best predicted by measures of distractibility and reality monitoring, with communication disorder in mania, although common and severe, not predicted by these cognitive performance measures. Furthermore, negative thought disorder in schizophrenics was not predicted by the cognitive measures. These results are discussed in terms of their implications regarding the differences in potential determinants of positive and negative thought disorders.

Medication may be required for the development of automatic information processing in schizophrenia.

Medicated and unmedicated schizophrenic patients and normal subjects (n's = 4) were examined on the extent to which their information-processing performance became automated over time, as reflected by increased competence in dual task performance. The central task was a computerized version of the Continuous Performance Test, and the secondary task was a word-list shadowing task. Normal subjects and medicated schizophrenic patients became much more efficient at performing both tasks simultaneously with practice, with unmedicated patients showing no improvement over time.

Cognitive deficits and thought disorder: II. An 8-month followup study.

Schizophrenic (n = 21) and manic (n = 19) patients were followed up an average of 8 months after an index assessment during an acute admission. These patients were tested at both assessments with laboratory tasks measuring distractibility and reality monitoring and were examined with clinical ratings of positive and negative thought disorder. For manic patients, none of the measures predicted the patients' clinical state of followup, while negative thought disorder, although rare, was temporally stable. For the schizophrenic patients, both negative thought disorder and distractibility were temporally stable, and more severe negative thought disorder was found at index assessment in patients who were psychotic at followup. The differential utility of laboratory and clinical indices for the prediction of overall clinical state is related to these data.