Search PubMed⌕ Search

Biomedical subjects

M F Green

Publications and source records attributed to M F Green.

At least 37 records · Page 2Linked to original sources
PubMed1998

Risperidone vs. haloperidol on reaction time, manual dexterity, and motor learning in treatment-resistant schizophrenia patients.

BACKGROUND: The present study compared the effects of risperidone vs. haloperidol on reaction time, manual dexterity, and two types of motor learning in a sample of treatment-resistant schizophrenia patients. METHODS: Fifty-six DSM-III-R diagnosed schizophrenia inpatients participated in a randomized, double-blind comparison of risperidone vs. haloperidol. Measures of reaction time, manual dexterity, motor sequence learning, and gross motor learning were administered at baseline, after 4 weeks of fixed-dose medication, and after 4 weeks of flexible-dose medication. RESULTS: The results indicated that patients receiving risperidone showed greater improvement in reaction time and manual dexterity than patients receiving haloperidol. After covarying symptom changes and movement disorder ratings, the results remained significant. The two treatment groups did not differ on either measure of motor learning. CONCLUSIONS: The differences in performance in reaction time and manual dexterity may be due to a specific beneficial effect of risperidone, as opposed to a general reduction in extrapyramidal symptom liability, compared to haloperidol.

Adult↗
PubMed1998

Prediction of the deficit syndrome from initial deficit symptoms in the early course of schizophrenia.

The Proxy for the Deficit Syndrome (PDS) was used with longitudinal symptom assessment data to identify recent-onset schizophrenia patients with the deficit syndrome. We evaluated the stability of deficit symptoms using repeated assessments. Symptom ratings were examined at an initial point of outpatient stabilization on antipsychotic medication as well as prospectively over the subsequent 12 months of outpatient treatment and assessment in 83 recent-onset schizophrenia patients. The vast majority of patients who were classified as non-deficit at the cross-sectional baseline assessment continued to remain non-deficit throughout the first year of treatment. However, patients classified as deficit at baseline did not consistently remain classified as showing deficit syndrome during the follow-through period. Thus, the presence of deficit symptoms detected in a single cross-sectional rating may be an inaccurate way to rate the deficit syndrome, yielding excessive false positives. Our use of longitudinal data allowed the stability criterion of the deficit syndrome to be evaluated using the PDS.

Adult↗
PubMed1998

Training and quality assurance with the Structured Clinical Interview for DSM-IV (SCID-I/P).

Accuracy in psychiatric diagnosis is critical for evaluating the suitability of the subjects for entry into research protocols and for establishing comparability of findings across study sites. However, training programs in the use of diagnostic instruments for research projects are not well systematized. Furthermore, little information has been published on the maintenance of interrater reliability of diagnostic assessments. At the UCLA Research Center for Major Mental Illnesses, a Training and Quality Assurance Program for SCID interviewers was used to evaluate interrater reliability and diagnostic accuracy. Although clinically experienced interviewers achieved better interrater reliability and overall diagnostic accuracy than neophyte interviewers, both groups were able to achieve and maintain high levels of interrater reliability, diagnostic accuracy, and interviewer skill. At the first quality assurance check after training, there were no significant differences between experienced and neophyte interviewers in interrater reliability or diagnostic accuracy. Standardization of training and quality assurance procedures within and across research projects may make research findings from study sites more comparable.

Clinical Competence↗
PubMed1998

Risperidone versus haloperidol for perception of emotion in treatment-resistant schizophrenia: preliminary findings.

Currently, little is known about the pharmacological effects of the new generation of antipsychotic medications on perception of emotion in schizophrenia. The present study was designed to compare the effects of risperidone versus haloperidol on the ability to perceive emotion in 20 treatment-resistant schizophrenia patients, using a double-blind design. Measures of emotion perception included a facial emotion identification test (still photographs presented on videotape), a voice emotion identification test (audiotape), and an affect perception test (brief interpersonal vignettes presented on videotape). These measures were administered during the final week of baseline and after 8 weeks of double-blind medication. Risperidone treatment produced a greater effect on patients' ability to perceive emotion compared with haloperidol treatment. Additionally, all patients who received risperidone demonstrated improvement in performance between baseline and retest, compared with four of the nine patients who received haloperidol. When changes in positive symptoms were statistically controlled, the results remained significant. These findings suggest that resperidone may facilitate patients' ability to accurately perceive emotion, an effect which may be mediated either directly by risperidone's pharmacological action or perhaps indirectly by its influence on basic neurocognition.

Adult↗
PubMed1997

Neurocognitive impairments associated with ambiguous handedness in the chronically mentally ill.

One form of atypical handedness, ambiguous handedness, is found in roughly one-quarter of chronic schizophrenic patients. Despite its prevalence, relatively little is known about the neurocognitive underpinnings of ambiguous handedness. In the present study we examined the performance of ambiguous (n = 19) and non-ambiguous (n = 39) handed chronically mentally ill inpatients on selected measures of verbal learning, motor learning and manual dexterity. The results revealed that ambiguous handers were more impaired than non-ambiguous handers in verbal learning, but not motor learning. Group differences in manual dexterity were significant for the entire sample, but not when analyses were limited to males. These findings suggest that impairments in verbal learning may be linked to the pathogenesis of ambiguous handedness in chronic psychiatric patients.

Adult↗
PubMed1997

Normal neurocognitive performance after extended practice in patients with schizophrenia.

This study evaluated new methods for improving the performance of patients with schizophrenia on specific neurocognitive tasks. Patients (n = 22) practiced sustained perceptual, memory and motor tasks 5 times/week for 10 weeks. Tasks were initially easy enough for patients to do well, but were made gradually more difficult over the 10 weeks. Patients received base pay and performance-based monetary supplements. No coaching or ongoing instruction was provided, and performance gains were assumed to depend upon implicit learning. High functioning healthy controls (n = 5) were given the same tasks at difficulty levels comparable to those achieved by patients after 10 weeks of practice. After 10 weeks of practice, 16 of the 22 patients performed as well or better than the best control on the perceptual and memory tasks, and 11 patients performed within the range of control subjects on the motor task. Half of the patients retested 6 months after training maintained supranormal performance, while the others showed marked performance declines. Patients with schizophrenia appear to have greater potential for neurocognitive improvement, and potentially for employment, than generally appreciated.

Adult↗
PubMed1997

Backward masking performance in unaffected siblings of schizophrenic patients. Evidence for a vulnerability indicator.

BACKGROUND: Visual masking is a procedure that is used to assess the earliest components of visual processing. In backward masking, the identification of an initial stimulus (the target) is disrupted by a later stimulus (the mask). The masking function can be divided into an early component (e.g., up to about 60 ms) that reflects the involvement of sensory-perceptual processes, and a later component that reflects susceptibility to attentional disengagement as the mask diverts processing away from the representation of the target. Schizophrenic patients show anomalies on both masking components. It is not known whether backward masking deficits reflect enduring genetic vulnerability to schizophrenia. METHODS: We assessed 32 unaffected siblings of schizophrenic patients and 52 normal control subjects on the early and late components of 4 masking conditions. The conditions differentially involved the sustained and transient visual pathways. RESULTS: The unaffected siblings showed poorer overall performance than control subjects on the masking procedures. More specifically, siblings showed anomalies on the early, sensory-perceptual component, but not on the later, attentional disengagement component. CONCLUSIONS: The backward masking performance deficits that have been observed in schizophrenic patients appear to reflect enduring vulnerability to the disorder rather than only the symptoms of the illness. This vulnerability appears to be associated with early, sensory-perceptual processes.

Adolescent↗
PubMed1997

Long-term morbidity associated with delayed treatment of first admission schizophrenic patients: a re-analysis of the Camarillo State Hospital data.

BACKGROUND: The authors examined data from a follow-up study of first admission schizophrenic patients treated with and without antipsychotic medications, who were discharged from the hospital within 6 months. It was predicted that patients who did not require antipsychotic medications for discharge would have a more favourable long-term outcome. METHODS: The subjects were part of the Camarillo State Hospital study conducted by May and colleagues in the late 1950s and early 1960s. Patients had been randomly assigned to treatment with and without antipsychotic medications. The number of rehospitalization days and total prescribed chlorpromazine equivalents were calculated for each patient for the 2 years following discharge. In order to assess patients' continuing ability to function, 11 patients from each group who met DSM-IV criteria for schizophrenia were matched for age, educational status at first admission, race, and gender; their Global Assessment of Functioning Scale (GAF) score was estimated across a period of 6-7 years following discharge. RESULTS: During the second year following discharge, patients initially treated with antipsychotic medications required fewer rehospitalization days than the initially non-medicated patients. Furthermore, 6-7 years following initial discharge, those patients initially treated with medications were functioning at a higher level, as measured by GAF scores, than patients not initially treated with antipsychotic medications. CONCLUSIONS: The results of this study suggest that, at least for this subgroup of patients, early treatment with antipsychotic medications both decreases the immediate morbidity associated with schizophrenia, and prevents detrimental changes possibly related to prolonged untreated psychosis.

Adolescent↗
PubMed1997

Social processing correlates of nonverbal social perception in schizophrenia.

This study examines the relationship of nonverbal social perception to other areas of social functioning in schizophrenia. One model of interpersonal problem-solving skills presents a sequence of receiving, processing, and sending skills. Social perception skills best fit the first stage in this model: receiving skills. As expected, schizophrenic subjects (N = 29) were less skillful than normal subjects (N = 15) on measures of social problem solving, understanding of social sequences, and social judgment. In addition, performance on these tasks was significantly related to nonverbal social perception, but only for the schizophrenic group. Thus, deficits in nonverbal social perception are related to other measures of social functioning in schizophrenia. Implications of these findings for understanding and treating social deficits in schizophrenia are discussed.

Adult↗
PubMed1997

Does risperidone improve verbal working memory in treatment-resistant schizophrenia?

OBJECTIVE: Treatment efficacy in schizophrenia is typically defined in terms of symptom reduction. However, new antipsychotic medications could potentially have an impact on aspects of disability, such as neurocognitive deficits. The authors evaluated the effects of risperidone on verbal working memory, a memory component of theoretical interest because of its link to prefrontal activity and of practical interest because of its link to psychosocial rehabilitation. METHOD: Verbal working memory of 59 treatment-resistant schizophrenic patients was assessed as part of a randomized, double-blind comparison of treatment with risperidone and haloperidol. Verbal working memory was measured under both distracting and nondistracting conditions at baseline and after 4 weeks of both fixed- and flexible-dose pharmacotherapy. RESULTS: Risperidone treatment had a greater beneficial effect on verbal working memory than haloperidol treatment across testing conditions (with and without distraction) and study phases (fixed and flexible dose). The treatment effect remained significant after the effects of benztropine cotreatment, change in psychotic symptoms, and change in negative symptoms were controlled. Neither benztropine status nor symptom changes were significantly related to memory performance. CONCLUSIONS: Treatment with risperidone appears to exert a more favorable effect on verbal working memory than treatment with a conventional neuroleptic. The beneficial effect appears to be due, at least partially, to a direct effect of the drug, possibly through antagonism of the 5-HT2A receptor. Results from this study suggest that pharmacotherapeutic efficacy in schizophrenia treatment could be broadened to include impact on neurocognitive abilities.

Adult↗
PubMed1996

What are the functional consequences of neurocognitive deficits in schizophrenia?

OBJECTIVE: It has been well established that schizophrenic patients have neurocognitive deficits, but it is not known how these deficits influence the daily lives of patients. The goal of this review was to determine which, if any, neurocognitive deficits restrict the functioning of schizophrenic patients in the outside world. METHOD: The author reviewed studies that have evaluated neurocognitive measures as predictors and correlates of functional outcome for schizophrenic patients. The review included 1) studies that have prospectively evaluated specific aspects of neurocognition and community (e.g., social and vocational) functioning (six studies), 2) all known studies of neurocognitive correlates of social problem solving (five studies), and 3) all known studies of neurocognitive correlates and predictors of psychosocial skill acquisition (six studies). RESULTS: Despite wide variation among studies in the selection of neurocognitive measures, some consistencies emerged. The most consistent finding was that verbal memory was associated with all types of functional outcome. Vigilance was related to social problem solving and skill acquisition. Card sorting predicted community functioning but not social problem solving. Negative symptoms were associated with social problem solving but not skill acquisition. Notably, psychotic symptoms were not significantly associated with outcome measures in any of the studies reviewed. CONCLUSIONS: Verbal memory and vigilance appear to be necessary for adequate functional outcome. Deficiencies in these areas may prevent patients from attaining optimal adaptation and hence act as "neurocognitive rate-limiting factors." On the basis of this review of the literature, a series of hypotheses are offered for follow-up studies.

Activities of Daily Living↗
PubMed1995

Backward masking performance during and after manic episodes.

In a longitudinal design, 16 inpatients with bipolar mood disorder and 16 normal control participants were administered measures of backward masking. Bipolar inpatients were assessed while actively manic and again following manic episode. Clinical state was determined from ratings on an expanded version of the Brief Psychiatric Rating Scale. Two backward masking paradigms were used: (a) a staircase method, which yielded a critical interstimulus interval, and (b) set interstimulus intervals, which provided a masking function. Bipolar patients performed significantly worse than the normal controls at both sessions, but the Group X Session interaction was nonsignificant with both masking procedures. The masking performance deficit for the manic patients was not related to the presence of psychotic symptoms but seemed to be partially associated with lithium treatment. The results indicate that the impaired masking performance of manic patients is not strictly limited to the period of the manic episode.

Adolescent↗
PubMed1995

Modification of performance on the span of apprehension, a putative marker of vulnerability to schizophrenia.

The present study examined the effectiveness of 2 types of intervention (contingent monetary reinforcement and enhanced instruction) on span of apprehension performance. Forty chronic schizophrenia inpatients (26 men, 14 women) received a 3- and 12-letter array version of the span of apprehension task 4 times: baseline, intervention, immediate posttest, and 1-week follow-up. All patients were randomly assigned to 1 of 4 groups that differed according to method of intervention: repeat administration, monetary reinforcement only, instruction only, and monetary reinforcement plus instruction. The combination of monetary reinforcement plus instruction yielded significantly greater improvement in span accuracy than the other methods of intervention. These findings suggest that performance on this putative vulnerability indicator can be modified through certain interventions.

Adult↗
PubMed1994

Backward masking in schizophrenia and mania. I. Specifying a mechanism.

BACKGROUND: Backward masking is a neuropsychological procedure that involves the earliest phases of visual processing. Compared with normal controls, the performance of schizophrenic patients is more disrupted by a visual mask. Masking procedures used previously with schizophrenic patients have combined two separate masking mechanisms (interruption and integration), which prevent interpretation of the nature of the abnormality. The current study systematically limited the masking mechanism to interruption to specify the underlying mechanisms. Manic patients were included to examine diagnostic specificity. METHODS: Sixty-three schizophrenic inpatients, 31 manic inpatients, and 48 normal controls received three versions of the backward masking procedure. One version used a high-energy mask that combines both integration and interruption mechanisms. Another procedure used a low-energy mask that works mainly through interruption. A final condition altered the features of the mask so that masking was almost entirely through interruption. RESULTS: Schizophrenic patients showed performance deficits across masking conditions, even in procedures that were largely limited to masking by interruption. The masking performance of the patients did not appear to fit a simple generalized deficit. Manic patients performed significantly worse than normal controls and comparably with the schizophrenic patients. CONCLUSIONS: Schizophrenic patients have abnormalities at least with interruptive mechanisms. The results suggest that deficits on masking procedures are not entirely specific to schizophrenia because comparable masking deficits were found in manic inpatients with chronic disease. The current study addresses the neuropsychological mechanisms of the masking deficit. The next step will be to investigate the contributions of two distinct neuroanatomical visual pathways to the masking abnormality in schizophrenia.

Adult↗
PubMed1994

Backward masking in schizophrenia and mania. II. Specifying the visual channels.

BACKGROUND: The backward masking procedures that have been used in psychopathology research have confounded two types of masking mechanisms (integration and interruption) and two types of visual channels (transient and sustained). In an earlier study, we attempted to limit the masking mechanism to interruption. The current study limited the role of sustained (parvocellular) visual channels to masking performance. METHODS: Masking procedures were altered in the following two ways to reduce reliance on sustained visual channels: (1) the spatial frequency was lowered by blurring the target and (2) a location task was used instead of an identification task. Manic patients were included to examine the specificity of deficits on these tasks to schizophrenia and to test the hypothesis that mania is associated with abnormalities on visuospatial tasks. RESULTS: Schizophrenic patients differed significantly from normal controls on both masking conditions. Manic patients also showed deficits relative to normal controls. Manic patients showed a significantly different masking function from that of schizophrenic patients on the location condition. CONCLUSIONS: Schizophrenic deficits within masking paradigms may involve abnormalities in transient, as opposed to sustained, visual channels. Masking performance deficits were also found in manic patients, but the underlying processes are probably different. A reformulation is offered concerning the nature of early visual processing deficits in schizophrenia.

Adult↗
PubMed1994

Preliminary evidence for an association between minor physical anomalies and second trimester neurodevelopment in schizophrenia.

Two types of markers, dermatoglyphics and minor physical anomalies, have been used as indicators of problems with fetal neurodevelopment in schizophrenia. The degree to which these markers overlap is not known. While it is agreed that abnormal dermatoglyphics reflect early second trimester maldevelopment, the timing of the development of minor physical anomalies has not been determined. Forty-six schizophrenic patients received assessments for minor physical anomalies, dermatoglyphics (right-left ridge count asymmetry and total finger ridge count), and information processing. Higher scores for minor physical anomalies were associated with greater dermatoglyphic asymmetry. Patients who had both types of indicators (high minor physical anomalies and dermatoglyphic asymmetry) did not differ on information-processing measures from patients who had neither. On the basis of the timing of dermatoglyphic development (weeks 14-22 of gestation), the association between minor physical anomalies and dermatoglyphic asymmetry suggests that the relatively high rate of minor physical anomalies observed in schizophrenia can be considered to reflect at least second trimester maldevelopment.

Adult↗
PubMed1994

Cognitive correlates to social cue perception in schizophrenia.

Previous research has examined social skill learning in schizophrenic patients in relation to information-processing deficits and psychiatric symptoms. Relationships were examined in the current report between social cue perception, thought to be an early and necessary component of skill learning, and various information-processing deficits and psychiatric symptoms. Twenty-six inpatients with DSM-III-R diagnoses of schizophrenia completed measures of social cue perception, cognitive functioning, and psychiatric symptoms. Results showed that cue perception was significantly related to measures of early visual processing, recognition memory, and psychiatric symptoms of withdrawal/retardation. Implications of these findings for future research into the social-perceptual deficits of schizophrenic patients are discussed.

Adult↗