Quantitative EEG in schizophrenia and in response to acute and chronic clozapine treatment

Topographic quantitative electroencephalographic (EEG) power and frequency indices were collected in 17 treatment refractory, DSM-III diagnosed schizophrenic patients, before and after acute (single dose) and chronic (six weeks) clozapine treatment, as well as in 17 healthy volunteers. Prior to treatment, patients exhibited greater overall absolute theta power, slower mean alpha frequency and elevated absolute delta and total power in anterior regions. Acute dosing increased total spectrum power globally, slow wave power posteriorally, mean alpha frequency and beta power anteriorally and decreased alpha power posteriorally. Six weeks of clozapine treatment significantly reduced clinical ratings of positive and negative symptoms as well as symptoms of global psychopathology. Chronic treatment resulted in EEG slowing as shown by decreases in relative alpha power, mean beta/total spectrum frequency and by widespread increases in absolute total and delta/theta power. The preliminary findings suggest that brain electric profiling may be a promising tool for assessing and understanding the central impact of pharmacotherapeutic interventions in schizophrenia.

Neuropsychological change in schizophrenia after 6 weeks of clozapine

Neuropsychological change after 6weeks of clozapine treatment was examined in 18 treatment-refractory patients to test anticipated domain-specific cognitive improvements. The first aim of this study was to test the assumption that increased homogeneity of sample and treatment would yield an experimental design with sufficient sensitivity to detect general intellectual changes with clozapine that were not apparent in one previous investigation. The second aim was to test predictions derived from a domain-specific review of all other investigations with clozapine suggesting salient gains on tests sensitive to motor and mental speed, visual spatial manipulation, and new learning of verbal material. The results showed that the comprehensive neuropsychological test battery was sensitive to general cognitive changes with clozapine, and supported the hypothesized domain-specific gains on tests of motor and mental speed, visual spatial manipulation and new verbal learning. Novel gains were also apparent on tests of new learning with nonverbal material. The results are discussed in relation to aspects of experimental design necessary for the evaluation of prospective medication-induced changes in cognitive skill, particularly in future investigations designed to differentiate between second-generation antipsychotic medications.

Neuropsychological change in patients with schizophrenia after treatment with quetiapine or haloperidol

OBJECTIVE

To assess the efficacy of quetiapine, a recently introduced second generation antipsychotic medication, in reducing cognitive impairment in patients with schizophrenia.

DESIGN

Prospective, randomized, double-blind clinical trial.

PATIENTS

25 patients who met the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, (DSM-IV) criteria for schizophrenia were recruited from 3 Canadian hospitals.

INTERVENTION AND OUTCOME MEASURES

After a 48-hour washout period, 25 patients with schizophrenia were randomly assigned to double-blind treatment with quetiapine or haloperidol for 6 months and evaluated with rating scales for psychotic symptoms, mood and extrapyramidal side effects, as well as standardized neuropsychological measures sensitive to 6 cognitive domains: fine motor skill, attention span, verbal reasoning and fluency, visuospatial construction and fluency, executive skills and visuomotor tracking, and immediate recall of verbal and nonverbal materials. The measures were repeated 8 weeks and 6 months after treatment was initiated.

RESULTS

Quetiapine improved psychosis and mood without inducing extrapyramidal symptoms. Quetiapine also had beneficial effects on cognitive skills, particularly verbal reasoning and fluency skills and immediate recall, with additional improvements on executive skills and visuomotor tracking and on the average of the 6 cognitive domains with sustained treatment. Patients taking haloperidol showed improvements in general clinical status, but no specific improvements on the positive syndrome, the negative syndrome, depression ratings or cognitive skills.

CONCLUSIONS

These preliminary results support the potential value of quetiapine for improving cognitive impairment in patients with schizophrenia and emphasize the importance of further research with this promising atypical antipsychotic.

EEG hemispheric asymmetry as a predictor and correlate of short-term response to clozapine treatment in schizophrenia

In search of early neuroleptic response predictors in schizophrenia, functional interhemispheric and intrahemispheric asymmetry indices, derived from spectrally analyzed resting electroencephalographic (EEG) activity, were examined in 17 schizophrenic patients prior to open label treatment with the atypical neuroleptic clozapine. Compared to EEG asymmetry indices derived from a normative data bank, patients exhibited significant interhemispheric (left greater than right) and intrahemispheric (anterior greater than posterior) deviations in delta, theta, alpha and beta frequency bands. Intrahemispheric indices were positively correlated with clinical ratings of positive symptoms and global psychopathology. Clozapine-induced improvements in positive and negative symptoms and global psychopathology symptom ratings were related to pretreatment intrahemispheric asymmetry only, with relationships varying with symptom, recording region and frequency band. The results are discussed in relation to the neurobiology of schizophrenia and the utility of EEG as an informative predictor of treatment response.

DRD3 and DAT1 genes in schizophrenia: an association study

OBJECTIVE

To investigate the role of the dopamine receptor 3 (DRD3) and transporter 1 (DAT1) genes in schizophrenia or in modulating its phenotype.

METHODS

a Ser9Gly polymorphism in codon 9 of the DRD3 and a VNTR polymorphism in the DAT1genes were examined in two groups of schizophrenic patients, one of excellent neuroleptic responders (N=42) and one of nonresponders (N=64). A group of healthy volunteers screened for major psychiatric disorders was also included (N=89). In addition, age at onset of psychotic symptoms, attention performance and family loading for schizophrenia spectrum disorders were compared between patients with different genotypes in the DRD3 and DAT1 genes.

RESULTS

No significant differences in the allelic distribution of the DRD3 and DAT1 polymorphisms were detected between schizophrenic patients and controls. A trend toward an excess of DRD3 genotype Gly/Gly was observed in neuroleptic nonresponder schizophrenic patients compared to controls (chi(2)=3. 30, df=1, p=0.07). No significant differences in age at onset of psychotic symptoms, attention task performance or family loading for schizophrenia spectrum disorders were observed between groups with different DRD3 and DAT1 genotypes.

CONCLUSION

These results do not support the role of either of these genes in increasing susceptibility to schizophrenia or in modulating its phenotype in the studied population.

Longitudinal comparative study of risperidone and conventional neuroleptics for treating patients with schizophrenia. The Quebec Schizophrenia Study Group

This study compared the long-term (12 months) effectiveness of risperidone (RP) with that of conventional neuroleptics (CNs) in a population with chronic schizophrenia who had shown suboptimal response to CNs. A randomized, open, parallel, multicenter design was used. One hundred eighty-four subjects meeting DSM-IV criteria for schizophrenia were randomly assigned to receive either RP or a CN, and 165 of them completed the follow-up. Outcome measures were taken at 3, 6, and 12 months and included the Positive and Negative Syndrome Scale (PANSS) and the Extrapyramidal Symptom Rating Scale. Within this 12-month follow-up, RP was found to be superior to CNs in terms of both the average change in score from baseline on the PANSS (p = 0.006) and the proportion of good responders (as defined by a 20% decrease in total PANSS scores;p = 0.03). For positive symptoms, the effectiveness of the RP treatment tended to increase over time. At 12 months, the percentage of good responders in the RP group was twice as large as that in the CN group (30% vs. 15%;p = 0.03). The superiority of RP over CNs was constant over the three dose categories. In both the RP and the CN groups, the maximum decrease in psychopathology was achieved with the lowest dose range. A worsening of akathisia was less frequent in subjects receiving RP than in those receiving CNs (p = 0.02). In conclusion, this study showed that, compared with CNs, RP is beneficial in the treatment of patients with chronic schizophrenia and that some of these benefits may appear only after longer-term treatment.

Association between the methylenetetrahydrofolate reductase 677C-->T missense mutation and schizophrenia

The schizophrenia phenotype is heterogeneous with respect to clinical presentation, long-term response to medication, and outcome, possibly reflecting genetic heterogeneity and/or the presence of modifier genes. Compared to non-responders, schizophrenic patients who are responders to neuroleptic medications are characterized by a high female/male ratio, a better long-term outcome and more frequently disturbed dopamine neurotransmission. In this study, we compared two groups of schizophrenic patients selected on the basis of their long-term response to neuroleptics (excellent responders and non-responders) and a group of healthy volunteers, with regard to a missense mutation (677C-->T) in the methylenetetrahydrofolate reductase (MTHFR) gene. This polymorphism was chosen because it is functional and was previously associated with schizophrenia. The present study revealed a significant association between schizophrenia and allele T of this gene. This association was entirely due to an over-representation of allele T in responder patients compared to controls; nonresponder patients did not differ from controls. Genotype TT was more frequent in responder patients compared to controls, thus replicating the findings of Arinami et al. These results strongly suggest that the MTHFR gene is involved in the pathogenesis of schizophrenia characterized by a rapid and sustained therapeutic response to typical neuroleptics and/or a good long-term prognosis/favorable therapeutic outcome.

Neuropsychological change in early phase schizophrenia during 12 months of treatment with olanzapine, risperidone, or haloperidol. The Canadian Collaborative Group for research in schizophrenia

BACKGROUND

The purpose of this investigation was to test the efficacy of novel antipsychotic medications in the treatment of cognitive impairment in early phase schizophrenia.

METHODS

Sixty-five patients in this multicenter double-blind study were randomly assigned to olanzapine (5-20 mg), risperidone (4-10 mg), or haloperidol (5-20 mg). Standard measures of clinical and motor syndromes were administered, as well as a comprehensive battery of tests to assess (1) motor skills, (2) attention span, (3) verbal fluency and reasoning, (4) nonverbal fluency and construction, (5) executive skills, and (6) immediate recall at baseline and after 6, 30, and 54 weeks of treatment.

RESULTS

The general cognitive index derived from the 6 domain scores revealed a significantly greater benefit from treatment with olanzapine relative to haloperidol and olanzapine relative to risperidone, but no significant difference was shown between risperidone and haloperidol. The improvement related to olanzapine was apparent after 6 weeks and enhanced after 30 and 54 weeks of treatment. Exploratory within-group analyses of the 6 cognitive domains after a conservative Bonferroni adjustment revealed a significant improvement with olanzapine only on the immediate recall domain, and similar analyses of the 17 individual tests revealed a significant improvement with olanzapine only on the Hooper Visual Organization Test.

CONCLUSIONS

These data suggest that olanzapine has some superior cognitive benefits relative to haloperidol and risperidone. A larger sample replication study is necessary to confirm and generalize the observations of this study and begin evaluation of the implications of this change to cerebral function and quality of life for people with schizophrenia.

Analysis of 14 CAG repeat-containing genes in schizophrenia

Recently, it has been suggested that trinucleotide repeat-containing genes may be involved in the etiology of schizophrenia. This study was aimed at investigating putative associations between allelic variants or expansions of CAG repeat-containing genes (CAGrCG) and schizophrenia or its variability with respect to responsiveness to conventional neuroleptics. CAG repeat allelic variants of 14 expressed sequences were compared among three groups of subjects: neuroleptic-responder (R; n = 43) and neuroleptic-nonresponder (NR; n = 63) schizophrenic patients, and a control group (C; n = 122). No CAG expansions, in the range of those observed in neurodegenerative diseases, were identified in these 14 expressed sequences. The sizes of CAG repeat for the hGT1 gene were marginally different among the three groups of subjects (Kruskal-Wallis H (2, 456) = 10.48, Bonferroni corrected P = 0.047). Comparisons among the different groups indicated that neuroleptic responders have shorter alleles compared to controls (Mann-Whitney adjusted Z = -3.23, P = 0.0012). NR patients were not different from controls. These preliminary results suggest that the hGT1 gene, or a gene in its vicinity, may be involved in the etiology of schizophrenia or in modifying the disease phenotype with regard to outcome and/or neuroleptic responsiveness. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 88:694-699, 1999.

Retention rates in placebo- and nonplacebo-controlled clinical trials of schizophrenia

OBJECTIVE

To determine if the inclusion of a placebo control in clinical trials of schizophrenia affects retention rates in the first 35 days of inclusion relative to trials that did not have a placebo control.

METHOD

This was a retrospective study of 8 double-blind clinical trials, 5 of which had a placebo control while 3 did not. Using survival analysis, retention rates between the placebo-controlled trials (PCTs) and the nonplacebo-controlled trials (NPCTs) were compared. Screening and percentage improvement on Brief Psychiatric Rating Scale and Positive and Negative Syndrome Scale scores were compared.

RESULTS

Significantly more patients were retained in the 35-day period for NPCTs. Also, the PCT group had significantly more psychopathology at screening than did the NPCT group.

CONCLUSIONS

Differences in retention rates between PCTs and NPCTs cannot be uniquely attributed to placebo itself.

Lack of association between the hSKCa3 channel gene CAG polymorphism and schizophrenia

Genetic anticipation, a phenomenon characterized by increased severity of symptoms and earlier age at onset of a disease in successive generations, is believed to be present in schizophrenia. In several neurodegenerative diseases showing anticipation, the mutation causing the disease is an expanded trinucleotide repeat. Therefore, genes containing trinucleotide repeats prone to expansion have become a suitable family of candidate genes in schizophrenia. A human calcium-activated potassium channel gene (hSKCa3), possibly mapping to chromosome 22q11-13, a region previously linked to schizophrenia, was recently described. This gene contains two contiguous expressed CAG repeat stretches. Recently, long allelic variants of one of these CAG repeats were found to be overrepresented in schizophrenic patients compared to normal controls. In this study we attempted to replicate this result and to study the relationship between the length of this CAG repeat on the one hand and the severity and age at onset of the disease on the other hand. No association with the disease or correlation with the severity of schizophrenia was identified. In addition, hSKCa3 was mapped to chromosome 1. Our results do not support the involvement of this particular CAG repeat-containing gene in schizophrenia.

T102C polymorphism in the 5HT2A gene and schizophrenia: relation to phenotype and drug response variability

Although genes play a major role in the etiology of schizophrenia, no major genes involved in this disease have been identified. However, several genes with small effect have been reported, though inconsistently, to increase the risk for schizophrenia. Recently, the 5HT2A 2 allele (T102C polymorphism) was reported to be over-represented in patients with schizophrenia. Other reports have found an excess of allele 2(C) only in schizophrenic patients who are resistant to clozapine, not in those who respond to clozapine. In this study, the 5HT2A receptor allele 2 frequencies were compared between 2 groups of patients with schizophrenia (39 responders and 63 nonresponders) based on long-term outcome and response to typical neuroleptics. A control group of 90 healthy volunteers screened for mental disorders was also included. Genotype 2/2 tended to be more frequent in patients with schizophrenia with poor long-term outcome and poor response to typical neuroleptics (Bonferroni corrected p = 0.09). This difference was significant in men (Bonferroni corrected p = 0.054) but not in women. In addition, the age at first contact with psychiatric care was significantly younger in the patients with schizophrenia with genotype 2/2 than in patients with genotype 1/1. These result suggest that the 5HT2A-receptor gene may play a role in a subset of schizophrenia characterized by poor long-term outcome and poor response to neuroleptics.

The treatment of negative symptoms: a clinical and methodological study

The primary objective of this study was to evaluate the efficacy, safety and tolerability of remoxipride (controlled release) versus haloperidol in patients with negative symptoms. The study comprised a multicentre, randomised, double-blind, parallel-group clinical trial. Two hundred and five patients were randomised to either remoxipride or haloperidol. Patients eligible for this study were aged 18-65 years, met the DSM-III-R diagnosis for chronic schizophrenia and the Positive and Negative Symptoms Scale (PANSS) criteria for predominant negative symptoms. There was a statistically significant reduction in the PANSS scores of at least 20% from baseline to last rating for 39 remoxipride (49.4%) and 45 haloperidol (47.6%) treated patients. There were no statistical differences found between the two treatment groups with respect to improvement of negative symptoms and adverse events. The PANSS data suggest that both remoxipride and haloperidol improve the cluster of negative symptoms concerned with social functioning. In addition, the design of the study provides a methodology that is appropriate to the study of primary negative symptoms in schizophrenia.

Event-related potentials in schizophrenic patients during a degraded stimulus version of the visual continuous performance task

Previous studies of the auditory P300 event-related potential (ERP) have reported smaller amplitudes in chronic schizophrenics but similar consistencies have not been observed with visual P300s. This study examined P300s in symptomatically stable, medicated, chronic schizophrenics (n = 14) and normal controls (n = 14) performing a visual continuous performance task utilizing degraded stimuli to burden encoding processes. Performance analysis found slower response times, fewer target detections and more false alarms in patients than in controls. Analysis of ERPs showed P300 amplitudes of schizophrenics to be significantly smaller than those of controls and, unlike controls, schizophrenics failed to exhibit significant target vs. non-target P300 amplitude differences. Discriminant analysis indicated target and non-target midline (Fz, Cz, Pz) P300 amplitudes together correctly classified all patients and controls. Exploratory topographic analysis indicated that P300 amplitudes were not asymmetrical in patients, as has been observed with auditory P300s, and, unlike the performance measures, the P300s did not correlate with the patient's positive or negative symptom ratings. The implications of these findings are described in relation to attentional disturbances and trait versus state issues in schizophrenics.

Phase-IV multicentre clinical study of risperidone in the treatment of outpatients with schizophrenia. The RIS-CAN-3 Study Group

OBJECTIVE

Since most clinical trials of atypical antipsychotics have been conducted in hospitalized patients, a Phase-IV, multicentre, 8-week, open-label, flexible-dose study was performed to assess the efficacy and safety of risperidone in outpatients with schizophrenia.

METHOD

Three hundred and thirty patients with a Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R) diagnosis of schizophrenia were enrolled at 61 Canadian sites. Upon trial entry, the patients had their neuroleptic and antiparkinsonian drugs discontinued, and treatment with risperidone was initiated at a dose of 2 mg daily, then increased by 2 mg daily on each of the 2 following days until the initial target dose of 6 mg daily was reached on day 3. No further titration was allowed until day 14, after which the dose could be increased or decreased.

RESULTS

During the stabilization phase (days 14-56), the dose was unchanged in 44% of the patients, increased in 24%, decreased in 23%, and titrated both up and down in 9% of the patients. In the efficacy-evaluable population (n = 292), treatment with risperidone produced substantial (-26.4) and significant (P = 0.0001) improvement in the total Positive and Negative Syndrome Scale (PANSS) score. At the end of the study (week 8), 85% of patients were classified as clinically improved according to an a priori definition (that is, 20% or more decrease from baseline in total PANSS score). On their last study visit, 75% of patients reported their experience with risperidone as better than their previous neuroleptic therapy. Risperidone was generally well tolerated. The adverse events reported by more than 5% of the patients were insomnia, nausea, headache, somnolence, dizziness, fatigue, anxiety, vomiting, and ejaculation disorder. Seventy-four percent of the reported treatment-related adverse events were recorded during the first 2 weeks of the trial, possibly because of the discontinuation of prior neuroleptic and antiparkinsonian drugs followed by immediate upward titration of risperidone. However, only 8.5% of adverse events were reported to have occurred during week 3, and only 0.8% of adverse events were reported for week 8. Risperidone treatment produced significant improvements over baseline in the incidence and severity of extrapyramidal symptoms (EPS). A slight but statistically significant increase in body weight was observed.

CONCLUSIONS

The results of this open-label, Phase-IV trial in a large population of outpatients with schizophrenia found that risperidone was superior to the neuroleptics that patients had previously taken in terms of efficacy and severity of EPS. Our results suggest the use of risperidone at lower doses in outpatients with schizophrenia.

Age of onset in familial and sporadic schizophrenia

We have studied the gender and family history differences with regard to age of onset of schizophrenia. These differences have often been viewed as an important clue to the aetiology of the illness. Patients from three centres in Europe and Canada were included in the study. A sample of 1089 subjects was categorized according to the subject's sex, family history of schizophrenia, and the centre. The principal statistical method was analysis of variance. Patients with no family history of schizophrenia had a consistently higher average age of onset. This effect was seen in both male and female subjects across all three groups. These results support the relationship between familial risk and early onset, but no interaction of gender and family history was found.

Responses of indicator bacteria to forest soil amended with municipal sewage sludge from aerated and non-aerated ponds

The survival of faecal and total coliform bacteria and Streptococcus faecalis (indicator bacteria) were monitored in experimental plots receiving various amounts of biological or dephosphatation municipal sewage sludge. Biological sludge was applied on coniferous and mixed regenerative forest soils. The results show that except for total coliforms, there was little significant treatment effect on the indicator bacteria numbers in all of the sites. In most cases, there was a significant time effect, indicating that bacterial populations vary over time, according to environmental factors such as temperature, moisture or nutrient level conditions. In total coliform bacteria, populations varied over time but also in function of treatment levels. The present study suggests that even if the standards of Québec (Canada) for sludge application are respected, there may be some risk for bacterial contamination depending on the types of sewage sludge and forest habitat. Although there is only a short-term effect, high slopes can influence the movement of the indicator bacteria and may potentially cause some contamination problems.

An open trial of the D1 antagonist SCH 39166 in six cases of acute psychotic states

Six psychotic patients were included in a four-week study of the effects of the D1 selective antagonist SCH 39166 given as monotherapy. Four had a diagnosis of schizophrenia, and two suffered from a schizoaffective disorder. All presented with an acute psychotic exacerbation at the beginning of the trial. SCH 39166 was progressively increased from 50 mg/day to 600 mg/day. In the four schizophrenic patients, the BPRS worsened, and three out of the four failed to complete the study because of this. Three schizophrenic patients were aggressive or violent after abrupt discontinuation of treatment. In the two patients with schizoaffective disorder the BPRS improved during the trial, but they had an acute relapse immediately after treatment discontinuation. Extrapyramidal symptoms improved in three of the six patients, and worsened in one.

Risperidone in the treatment of pervasive developmental disorder

Elevated concentrations of blood serotonin have been documented in autistic children and mentally retarded adults. Antiserotonergic pharmacotherapy has been partially effective in treating a subgroup of children with autistic disorder. Therefore, the possibility is raised that an antiserotonergic treatment may be of value to adult psychiatric patients with a history of pervasive developmental disorder. Two such cases are described where the patients underwent psychiatric and neuropsychological examination before and after treatment with risperidone, a potent 5-HT2 antagonist with additional D2 antagonistic properties. Particular improvements were documented in both patients, despite long histories of cognitive compromise and high likelihood of damage to the central nervous system.