The MATRICS Consensus Cognitive Battery (MCCB): clinical and cognitive correlates

The purpose of this study was to examine the cognitive and clinical correlates of the MATRICS Consensus Cognitive Battery (MCCB) which was originally developed to be an endpoint for cognitive enhancement clinical trials. In a sample of 117 people with schizophrenia and 77 healthy control participants we found the following: a) the MCCB was highly sensitive to the type and level of impairment typically observed in schizophrenia, b) the MCCB composite score was highly correlated with WASI Estimated Full Scale IQ score, c) that the MCCB domain scores were generally moderately-highly intercorrelated, d) that MCCB performance was minimally related to clinical symptom type and severity, and e) the MCCB is sensitive to employment status with better performance in employed vs. unemployed patients. These data support the validity of the MCCB as a sensitive measure of cognitive impairment in schizophrenia and suggest that MCCB performance is relevant for functional outcome. The data also suggest that the MCCB domain scores may offer limited resolution on discrete cognitive functions.

Bupropion sustained release added to group support for smoking cessation in schizophrenia: a new randomized trial and a meta-analysis

OBJECTIVE

To clarify the efficacy and tolerability of bupropion sustained release (SR) for the treatment of cigarette smoking in people with schizophrenia.

METHOD

The first study is a double-blind, placebo-controlled clinical trial with 32 outpatients from the Maryland Psychiatric Research Center. From May 2003 to July 2007, clinically stable people with a DSM-IV diagnosis of schizophrenia or schizoaffective disorder who smoked at least 10 cigarettes per day and who were interested in quitting smoking or cutting down were recruited for participation. All participated in a 9-week support group and were randomly assigned to receive 12 weeks of bupropion SR or placebo. The primary outcome measure was 4 weeks' sustained abstinence over the last 4 study weeks. Secondary outcome measures included decrease in smoking behavior and change in symptoms, neuropsychological performance, and side effects. In the second study, we performed an electronic literature search of MEDLINE in September 2008. Articles in English published between 2003 and 2008 were searched for the terms schizophrenia, bupropion SR, and smoking. Bibliographies of studies identified through the MEDLINE search were also examined. Case reports, open-label studies, crossover studies, and studies using nonstandard dosing of bupropion SR were excluded. In this way, 4 studies similar in methodology to the currently presented clinical trial were identified and the individual data combined in a meta-analysis. A random effects meta-analysis using Comprehensive Meta-Analysis software was used to obtain a pooled estimate of the odds ratio for 4-week smoking abstinence between bupropion SR and placebo.

RESULTS

There were no significant results on the primary or secondary smoking measures for the clinical trial, although a numeric advantage favored the bupropion SR group. There were no significant findings for secondary symptom or side effect measures and no significant change in neuropsychological performance. For the meta-analysis totaling 226 subjects, there were significant findings in favor of bupropion SR. The pooled estimate of the odds ratio for 4-week abstinence was 2.7 (95% CI, 1.3 to 5.7; P = .009), and clinically significant greater smoking reduction in the bupropion SR group, with pooled difference estimates increasing over time between groups, became statistically significant by week 5 of study medication (P < .02).

CONCLUSIONS

New clinical trial data and a meta-analysis strongly support the tolerability and efficacy of bupropion SR for the treatment of cigarette smoking in people with schizophrenia

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00176449.

Impaired kynurenine pathway metabolism in the prefrontal cortex of individuals with schizophrenia

The levels of kynurenic acid (KYNA), an astrocyte-derived metabolite of the branched kynurenine pathway (KP) of tryptophan degradation and antagonist of α7 nicotinic acetylcholine and N-methyl-D-aspartate receptors, are elevated in the prefrontal cortex (PFC) of individuals with schizophrenia (SZ). Because endogenous KYNA modulates extracellular glutamate and acetylcholine levels in the PFC, these increases may be pathophysiologically significant. Using brain tissue from SZ patients and matched controls, we now measured the activity of several KP enzymes (kynurenine 3-monooxygenase [KMO], kynureninase, 3-hydroxyanthranilic acid dioxygenase [3-HAO], quinolinic acid phosphoribosyltransferase [QPRT], and kynurenine aminotransferase II [KAT II]) in the PFC, ie, Brodmann areas (BA) 9 and 10. Compared with controls, the activities of KMO (in BA 9 and 10) and 3-HAO (in BA 9) were significantly reduced in SZ, though there were no significant differences between patients and controls in kynureninase, QPRT, and KAT II. In the same samples, we also confirmed the increase in the tissue levels of KYNA in SZ. As examined in rats treated chronically with the antipsychotic drug risperidone, the observed biochemical changes were not secondary to medication. A persistent reduction in KMO activity may have a particular bearing on pathology because it may signify a shift of KP metabolism toward enhanced KYNA synthesis. The present results further support the hypothesis that the normalization of cortical KP metabolism may constitute an effective new treatment strategy in SZ.

Dipyridamole monotherapy in schizophrenia: pilot of a novel treatment approach by modulation of purinergic signaling

BACKGROUND

Emerging data indicate the neuromodulator adenosine may play a role in the therapeutics of schizophrenia. Adenosine A(2A) receptor stimulation exerts a functional antagonism at postsynaptic D(2) receptors. Data from animal models relevant to schizophrenia support a therapeutic effect of modulating adenosinergic transmission in the ventral striatum. One previous clinical trial showed superiority of adjunctive dipyridamole, an adenosine reuptake inhibitor, compared to placebo in ameliorating positive symptoms in schizophrenia patients.

OBJECTIVES

The aim of this study was to examine the effects of dipyridamole monotherapy of 200 mg/day on positive and negative symptoms, with the goal of determining dosing for future adjunctive studies in schizophrenia.

METHODS

Twenty symptomatic schizophrenia participants were randomized to a 6-week double-blind trial comparing olanzapine (20 mg/day) to dipyridamole monotherapy (200 mg/day). Thirteen participants completed the treatment phase (eight on dipyridamole; five on olanzapine).

RESULTS

The olanzapine group showed a trend (p = 0.08) for superiority on BPRS total scores (mean ± SD: total BPRS score decreasing from 36.8 ± 2.3 at week 1, to 33.2 ± 5.5 at the end of the study). The mean total BPRS scores decreased from 36.4 ± 5.3 to 34.0 ± 7.7 in the dipyridamole group.

CONCLUSIONS

Although these pilot data do not support a significant antipsychotic effect of dipyridamole monotherapy, the results provide some evidence for examining dipyridamole (200 mg/day) as adjunct to symptomatic antipsychotic-treated schizophrenia patients.

Antagonist-elicited cannabis withdrawal in humans

Cannabinoid CB1 receptor antagonists have potential therapeutic benefits, but antagonist-elicited cannabis withdrawal has not been reported in humans. Ten male daily cannabis smokers received 8 days of increasingly frequent 20-mg oral Δ⁹-tetrahydrocannabinol (THC) dosages (40-120 mg/d) around-the-clock to standardize cannabis dependence while residing on a closed research unit. On the ninth day, double-blind placebo or 20- (suggested therapeutic dose) or 40-mg oral rimonabant, a CB1-cannabinoid receptor antagonist, was administered. Cannabis withdrawal signs and symptoms were assessed before and for 23.5 hours after rimonabant. Rimonabant, THC, and 11-hydroxy-THC plasma concentrations were quantified by mass spectrometry. The first 6 subjects received 20-mg rimonabant (1 placebo); the remaining 4 subjects received 40-mg rimonabant (1 placebo). Fourteen subjects enrolled; 10 completed before premature termination because of withdrawal of rimonabant from clinical development. Three of 5 subjects in the 20-mg group, 1 of 3 in the 40-mg group, and none of 2 in the placebo group met the prespecified withdrawal criterion of 150% increase or higher in at least 3 visual analog scales for cannabis withdrawal symptoms within 3 hours of rimonabant dosing. There were no significant associations between visual analog scale, heart rate, or blood pressure changes and peak rimonabant plasma concentration, area-under-the-rimonabant-concentration-by-time curve (0-8 hours), or peak rimonabant/THC or rimonabant/(THC + 11-hydroxy-THC) plasma concentration ratios. In summary, prespecified criteria for antagonist-elicited cannabis withdrawal were not observed at the 20- or 40-mg rimonabant doses. These data do not preclude antagonist-elicited withdrawal at higher rimonabant doses.

Effects of moderate-dose treatment with varenicline on neurobiological and cognitive biomarkers in smokers and nonsmokers with schizophrenia or schizoaffective disorder

CONTEXT

The administration of nicotine transiently improves many neurobiological and cognitive functions in schizophrenia and schizoaffective disorder. It is not yet clear which nicotinic acetylcholine receptor (nAChR) subtype or subtypes are responsible for these seemingly pervasive nicotinic effects in schizophrenia and schizoaffective disorder.

OBJECTIVE

Because α4β2 is a key nAChR subtype for nicotinic actions, we investigated the effect of varenicline tartrate, a relatively specific α4β2 partial agonist and antagonist, on key biomarkers that are associated with schizophrenia and are previously shown to be responsive to nicotinic challenge in humans.

DESIGN

A double-blind, parallel, randomized, placebo-controlled trial of patients with schizophrenia or schizoaffective disorder to examine the effects of varenicline on biomarkers at 2 weeks (short-term treatment) and 8 weeks (long-term treatment), using a slow titration and moderate dosing strategy for retaining α4β2-specific effects while minimizing adverse effects.

SETTING

Outpatient clinics.

PARTICIPANTS

A total of 69 smoking and nonsmoking patients; 64 patients completed week 2, and 59 patients completed week 8. Intervention Varenicline.

MAIN OUTCOME MEASURES

Prepulse inhibition, sensory gating, antisaccade, spatial working memory, eye tracking, processing speed, and sustained attention.

RESULTS

A moderate dose of varenicline (1) significantly reduced the P50 sensory gating deficit in nonsmokers after long-term treatment (P = .006), (2) reduced startle reactivity (P = .02) regardless of baseline smoking status, and (3) improved executive function by reducing the antisaccadic error rate (P = .03) regardless of smoking status. A moderate dose of varenicline had no significant effect on spatial working memory, predictive and maintenance pursuit measures, processing speed, or sustained attention by Conners' Continuous Performance Test. Clinically, there was no evidence of exacerbation of psychiatric symptoms, psychosis, depression, or suicidality using a gradual titration (1-mg daily dose).

CONCLUSIONS

Moderate-dose treatment with varenicline has a unique treatment profile on core schizophrenia-related biomarkers. Further development is warranted for specific nAChR compounds and dosing and duration strategies to target subgroups of schizophrenic patients with specific biological deficits.

Cigarette smoking and mortality risk in people with schizophrenia

This study examined effects of cigarette smoking on mortality risk in 1213 persons aged 19-69 years with schizophrenia-related psychotic disorders admitted to State of Maryland Hospitals between 1994 and 2000. Inpatient medical records from 7 hospitals were reviewed to obtain demographic information, diagnosis, medication use, as well as smoking and other substance use. Social Security Death Index data were used to identify deaths in the study group between 1994 and 2004. Death records were reviewed to obtain manner of death and underlying disorders. Of the 1213, 55% were smokers and 71% abused substances. There was an age × smoking interaction (χ(2) = 14.6, df = 1, P = .0001) for mortality, with estimated hazard ratios (HRs) for smokers vs nonsmokers of 2.1 among 35- to 54-year olds and HR of 0.7 among those aged 55-69 years. Five- and 10-year mortality rates for smokers aged 35-54 years were 7.0% and 14.2%, compared with 3.3% and 10.0% for nonsmokers, respectively (χ(2) = 5.53, df = 1, P = .019). Cardiac causes were identified in 43% of deaths in smokers but only 19% of deaths in nonsmokers (P < .006). For those aged 35-54 years, the odds of cardiac related death was increased by 12 fold in smokers relative to nonsmokers (HR = 12.4, χ(2) = 12.0, df = 1, P = .0005). Among people aged 35-54 years, those smoking greater than one pack daily have a significantly increased total mortality risk (HR = 2.7) vs nonsmokers. Cigarette smoking, particularly in people aged 35-54 years, contributes to an increased risk of death. Greater smoking severity significantly increases this risk. Smoking cessation in people with schizophrenia deserves significant attention.

The impact of substance abuse on osteoporosis screening and risk of osteoporosis in women with psychotic disorders

Review of the 1-year prevalence of screening for osteoporosis and of osteoporosis or idiopathic fracture in Maryland Medicaid administrative records found that screening rates did not differ among women in the control population, women with psychosis, and women with major mood disorders, but were reduced compared to controls in women with substance use disorder, with or without psychosis. Prevalence of osteoporosis was increased compared to controls in women with major mood disorders or women over 55 dually diagnosed with psychosis and substance use disorder.

INTRODUCTION

Osteoporosis is a major public health concern. Substance abuse and psychosis may be risk factors, however, frequency of screening and disease risk in women with psychotic disorders and substance use disorder (SUD) remains unknown.

METHODS

This study examined rates (FY 2005) of osteoporosis screening and disease risk in Medicaid enrolled women aged 50 to 64 (N = 18,953). Four diagnostic groups were characterized: (1) psychosis, (2) SUD, (3) major mood disorder, and (4) controls. The interaction of psychosis and SUD on screening and disease prevalence of osteoporosis was tested.

RESULTS

The prevalence of osteoporosis across the entire population was 6.7%. Four percent of those without an osteoporosis diagnosis received osteoporosis screening with no notable differences between psychosis and controls. Those with SUD, however, had a significant reduction in screening compared to controls (OR = 0.61, 95% CI = 0.40-0.91, p = 0.016). Women with a major mood disorder were more likely to have osteoporosis in their administrative record (OR = 1.32, 95% CI = 1.03-1.70, p = 0.028) compared to controls. Those who were dually diagnosed (SUD and psychosis) in the oldest ages (55-64 years) had a markedly higher prevalence of osteoporosis compared to controls (OR = 6.4 CI = 1.51-27.6, p = 0.012), whereas this interaction (SUD and psychosis) was not significant in the entire population over age 49.

CONCLUSIONS

Osteoporosis screening in the Medicaid population is significantly lower for women with SUD, after adjusting for age, race, and Medicaid enrollment category. The prevalence of osteoporosis appears markedly elevated in those with major mood disorders and those over age 55 dually diagnosed with schizophrenia and SUD.

Tobacco craving in smokers with and without schizophrenia

We examined tobacco craving and dependence in current smokers (18-65 years) with schizophrenia (N=100) and those without a psychiatric disorder (normal controls, N=100). During the 2-3h visit participants completed demographic and smoking-related questionnaires and provided a breath CO sample. The Tobacco Craving Questionnaire-Short Form (TCQ-SF) was administered. Immediately after smoking one cigarette, no difference in TCQ-SF total score was noted (46.7±19.5 schizophrenia, 42.8±18.2 controls, p=0.15); however, after 15 min TCQ-SF total score was significantly higher in people with schizophrenia (50.0±19.6) than in controls (38.6±19.4) (p=0.0014). TCQ-SF factors of emotionality (p=0.0015), compulsivity (p=0.0003) and purposefulness (p=0.0174) were significantly greater in the schizophrenia group than the control group. FTND scores (5.5±2.0 vs 5.3±2.0, p=0.62) number of cigarettes smoked daily (17.9±11.6 vs. 17.0±7.9), expired breath CO (28.0±14.5 ppm vs. 22.0±8.0 ppm) and age at smoking initiation (16.2±5.4 vs. 15.6±5.5 years, p=0.44) did not differ in the schizophrenia and control groups respectively. In conclusion, tobacco craving as measured by the TCQ-SF was significantly greater in people with schizophrenia than controls 15 min post-smoking, despite similar scores in dependence and similar smoking histories and current smoking patterns.

Subjective and physiological effects after controlled Sativex and oral THC administration

Sativex is a cannabis-plant extract delivering nearly 1:1 Δ(9)-tetrahydrocannabinol (THC) and cannabidiol (CBD) by oromucosal spray. It has been suggested that CBD attenuates THC-induced tachycardia, anxiety, and euphoria. In this study, pharmacodynamic effects were compared over 10.5 h in nine cannabis smokers randomly assigned to receive placebo, 5 and 15 mg oral synthetic THC, and low (5.4 mg THC, 5.0 mg CBD) and high (16.2 mg THC, 15.0 mg CBD) doses of Sativex. At therapeutic doses, no substantial CBD-induced modulation of THC's effects was evident. Oral THC and Sativex produced similar, clinically insignificant increases in heart rate, anxiety, and "good drug effects" with no serious adverse events. Oral and oromucosal THC have slower absorption, lower rate of THC delivery to the brain, and fewer associated adverse events as compared with smoked cannabis. These results indicate that Sativex has a pharmacodynamic safety profile comparable to that of oral THC at low, therapeutic doses.

Effects of the cannabinoid-1 receptor antagonist rimonabant on psychiatric symptoms in overweight people with schizophrenia: a randomized, double-blind, pilot study

Weight gain is a major adverse effect of several second-generation antipsychotic medications. Rimonabant is a cannabinoid-1 receptor antagonist that promotes weight loss in the general population. We conducted a 16-week, double-blind, placebo-controlled study of rimonabant (20 mg/d) in people with schizophrenia or schizoaffective disorder, based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria, who were clinically stable on second-generation antipsychotics. Participants had a body mass index of 27 kg/m or higher with hyperlipidemia or body mass index of 30 kg/m or higher, and no current substance abuse/dependence (except nicotine), more than weekly cannabis use, or recent depressive symptoms/suicidality. An exercise and dietary counseling group was offered weekly. Target enrollment was 60; the trial was terminated early because of withdrawal of rimonabant from the European market. Fifteen participants were randomized (7 rimonabant, 8 placebo); 5 completed in each group. Rimonabant was associated with a greater reduction in Brief Psychiatric Rating Scale total score versus placebo (mean ± SE difference, -1.9 ± 0.8, P = 0.02), driven by differences in the Brief Psychiatric Rating Scale anxiety/depression (-1.4 ± 0.35, P = 0.0004) and hostility (-0.7 ± 0.3, P = 0.02) factors. Group differences were not significant for the Calgary Depression Scale total score (P = 0.24), Scale for the Assessment of Negative Symptoms total score (P = 0.13), weight, blood pressure, or fasting lipids or glucose. Rimonabant was well tolerated with no significant adverse events. No significant weight loss, metabolic effects, or adverse psychiatric effects were associated with the cannabinoid-1 receptor antagonist rimonabant in this small sample of people with schizophrenia. The endocannabinoid system remains a promising target for pharmacotherapy of schizophrenia and obesity.

Exercise program adherence using a 5-kilometer (5K) event as an achievable goal in people with schizophrenia

People with schizophrenia have a higher prevalence of obesity than the general population. Many people with this illness struggle with weight gain, due, in part, to medications and other factors that act as obstacles to exercise and healthy eating. Several studies have shown the benefits of behavioral weight loss programs targeting eating and/or exercise in people with schizophrenia. Fewer studies have used competitive events as a goal for an exercise program. The current study tested the feasibility of preparing, using an exercise program, for a 5-kilometer (5K) event in people with schizophrenia. The exercise program was a 10-week training program consisting of three supervised walking/jogging sessions per week and a weekly educational meeting on healthy behaviors. Almost 65% (11/17) of the subjects participated in all of the training sessions, and 82% (14/17) participated in the 5K event. Participants did not gain a significant amount of weight during the exercise program (median weight change = 0.7 kg; 25th percentile 0.5, 75th percentile 3.9, p = .10). This study suggests that using an achievable goal, such as a 5K event, promotes adherence to an exercise program and is feasible in a population of people with chronic schizophrenia.

Adjunctive risperidone for partially responsive people with schizophrenia treated with clozapine

The large numbers of partial clozapine responders represent a major therapeutic challenge. Unfortunately, there are no clear data to support how best to treat these patients. This study examines the efficacy and safety of adjunctive risperidone in a well-defined treatment-resistant population optimally treated with clozapine. A total of 69 inpatients and outpatients with DSM-IV schizophrenia or schizoaffective disorder entered a 16-week double-blind, placebo-controlled, randomized clinical trial. Of them, 33 participants were randomized to risperidone and 36 were randomized to placebo. There was no significant group difference in the predefined response criteria. There were modest group differences for Brief Psychiatric Rating Scale (BPRS) positive symptoms, which were significant in the completer analysis (F=5.70; df=1, 70.3; p=0.02; ES=0.27) but not the intent-to-treat (ITT) analyses (F=3.01; df=1, 77.5; p=0.09; ES=0.19). A similar pattern was found for the BPRS total score, with the completer analysis showing a significant improvement in the risperidone group (F=5.21; df=1, 64.9; p=0.03; ES=0.27), whereas the ITT analysis was not significant (F=3.52; df=1, 71.3; p=0.06; ES=0.22). In addition, there was a small, but significant, group difference for negative symptoms, as measured by the SANS total score, which favored the risperidone group (F=5.67; df=1, 78.7; p=0.02; ES=0.24). There were no significant group differences on safety measures, including neuropsychological test and extrapyramidal symptom scores. A significant elevation of prolactin in the risperidone group was observed. The study results suggest that adjunctive risperidone may have a modest benefit for treatment-resistant clozapine patients. The study results are discussed in the context of previous double-blind studies of adjunctive risperidone. (clinicaltrials.gov, trial number: NCT00056498).

Cardiovascular disease mortality in patients with chronic schizophrenia treated with clozapine: a retrospective cohort study

BACKGROUND

Cardiovascular disease (CVD) mortality in schizophrenia is more frequent than in the general population. Whether second-generation antipsychotics (SGAs) increase risk of CVD morbidity and mortality has yet to be determined.

METHOD

We conducted a retrospective cohort study using an administrative database to identify patients with DSM-III- or DSM-IV-diagnosed schizophrenia, treated in Maryland, who started clozapine treatment (n = 1,084) or were never treated with clozapine (initiated on risperidone; n = 602) between 1994 and 2000. Deaths between 1994 and 2004 were identified by the Social Security Death Index, and death records were obtained.

RESULTS

During the 6- to 10-year follow-up period, there were 136 deaths, of which 43 were attributed to CVD. Cardiovascular disease mortality in patients aged younger than 55 years at medication start was approximately 1.1% (clozapine, 1.1%; risperidone, 1.0%) in both groups at 5 years and 2.7% (clozapine) and 2.8% (risperidone) at 10 years (chi(2)(1) = 0.12, P = .73). Patients who started treatment at ages >or= 55 years had CVD mortality of 8.5% (clozapine) and 3.6% (risperidone) at 5 years and 16.0% (clozapine) and 5.7% (risperidone) at 10 years (chi(2)(1) = 2.13, P = .144). In a Cox regression model, patients aged >or= 55 years were at greater risk of mortality than younger patients (hazard ratio = 4.6, P < .001); whites were at greater risk than nonwhites (HR = 2.1, P = .046); however, SGA treatment (HR = 1.2; 95% CI, 0.6-2.4; P = .61) and sex (HR = 0.9, P = .69) were not statistically significant predictors of CVD, nor was there a significant age x clozapine interaction (chi(2)(1) = 1.52, P = .22). Age-, race-, and gender-adjusted standardized mortality ratios were significantly elevated (clozapine, 4.70; 95% CI, 3.19-6.67; risperidone, 2.88; 95% CI, 1.38-5.30) compared to year 2000 rates for the Maryland general population but did not differ by antipsychotic group (chi(2)(1) = 1.42, P = .23).

CONCLUSIONS

The risk of CVD mortality in schizophrenia does not differ between clozapine and risperidone in adults despite known differences in risk profiles for weight gain and metabolic side effects. However, we cannot rule out an increased risk of CVD mortality among those starting treatment at ages 55 years or older.

Is motion perception deficit in schizophrenia a consequence of eye-tracking abnormality?

BACKGROUND

Studies have shown that schizophrenia patients have motion perception deficit, which was thought to cause eye-tracking abnormality in schizophrenia. However, eye movement closely interacts with motion perception. The known eye-tracking difficulties in schizophrenia patients may interact with their motion perception.

METHODS

Two speed discrimination experiments were conducted in a within-subject design. In experiment 1, the stimulus duration was 150 msec to minimize the chance of eye-tracking occurrence. In experiment 2, the duration was increased to 300 msec, increasing the possibility of eye movement intrusion. Regular eye-tracking performance was evaluated in a third experiment.

RESULTS

At 150 msec, speed discrimination thresholds did not differ between schizophrenia patients (n = 38) and control subjects (n = 33). At 300 msec, patients had significantly higher thresholds than control subjects (p = .03). Furthermore, frequencies of eye tracking during the 300 msec stimulus were significantly correlated with speed discrimination in control subjects (p = .01) but not in patients, suggesting that eye-tracking initiation may benefit control subjects but not patients. The frequency of eye tracking during speed discrimination was not significantly related to regular eye-tracking performance.

CONCLUSIONS

Speed discrimination, per se, is not impaired in schizophrenia patients. The observed abnormality appears to be a consequence of impairment in generating or integrating the feedback information from eye movements. This study introduces a novel approach to motion perception studies and highlights the importance of concurrently measuring eye movements to understand interactions between these two systems; the results argue for a conceptual revision regarding motion perception abnormality in schizophrenia.

Remission in schizophrenia: the relationship to baseline symptoms and changes in symptom domains during a one-year study

The concepts of partial recovery and remission have become increasingly important for the evaluation of the effectiveness of schizophrenia therapeutics. The relationship of baseline symptoms and changes in symptoms to remission of psychosis was evaluated. Fifty-six outpatients with residual schizophrenia completed a double-blind trial of olanzapine versus haloperidol and were then enrolled into a one-year open-label trial of olanzapine. Out of these 56 subjects, 13 (23%) met remission criteria at the beginning of the open-label treatment and were excluded. During the one-year study, 7/43 (16%) subjects met remission criteria. These subjects had significantly lower baseline ratings for tardive dyskinesia (TD) than subjects who did not achieve remission (1.8 +/- 1.5 vs. 4.2 +/- 4.6, P = 0.03). As expected, remitted subjects had significantly greater improvements in Brief Psychiatric Rating Scale total scores, positive subscale scores and scale for the Assessment of Negative Symptoms total scores. Remitted subjects also experienced a significantly greater improvement in depressive symptoms (P = 0.001), activation (P = 0.005), and Clinical Global Impressions scores (P < 0.001), as well as greater improvements in extrapyramidal symptoms (P = 0.007) and TD (P < 0.001). These results suggest that the relationship of depressive symptoms and improved side effects to the construct of remission in schizophrenia may deserve special attention. Future studies should aim to relate remission criteria to functional outcomes, cognition, and other important symptom domains.

Impaired visual working memory consolidation in schizophrenia

This study investigated working memory (WM) consolidation, that is, the time required to create durable WM representations, at different levels of WM load in schizophrenia. Twenty-three schizophrenia spectrum patients and 16 control subjects participated in a change-detection task in which a sample array of 1-3 squares appeared followed by a delay and a test array. An array of pattern masks was inserted into the delay interval--covering the locations of the sample-array squares--100-800 ms after the offset of the sample array. If a durable WM representation is formed prior to mask onset, the mask should not impair performance. The degree of masking at an interval reflects the degree of WM consolidation at that time. Neither group showed masking at set size 1. Unlike controls, patients demonstrated robust masking effects at set size 2. Both groups showed masking at set size 3, but masking effects were larger and longer lasting in patients. These data demonstrate abnormally prolonged WM consolidation in schizophrenia. This impairment may slow the formation of stable representations of the visual environment, impacting everyday visually guided behavior.

A randomized double-blind trial of atomoxetine for cognitive impairments in 32 people with schizophrenia

BACKGROUND

Currently available antipsychotic medications offer only modest, if any, effects on cognitive performance in people with schizophrenia. Treatments that would improve these impairments could lead to better functional outcomes. Atomoxetine is a nonstimulant, selective norepinephrine reuptake inhibitor approved for the treatment of attention-deficit/hyperactivity disorder. In animals, it has been shown to increase extracellular levels of acetylcholine and dopamine in cortical and hippocampal regions.

METHOD

Following a 2-week stabilization period, 32 subjects with DSM-IV-diagnosed schizophrenia or schizoaffective disorder were randomly assigned to atomoxetine (80 mg daily) or placebo for 8 weeks. All subjects were treated with antipsychotic monotherapy (excluding clozapine, aripiprazole, and first-generation antipsychotics). Neuropsychological test performance was the primary outcome variable, and the neuropsychological test battery included measures of attention, motor speed, executive function, processing speed, verbal and visual memory, and working memory (rated at baseline and end point). Symptom and side-effect ratings were performed every 2 weeks. The study was conducted from April 2004 through December 2006.

RESULTS

There were no treatment group differences on the primary study outcome measure (overall mean z-score: Wilcoxon chi(2) = 0.21, df = 1, p = .64); nor was there significant evidence of variation in treatment effects on z-score changes across the individual neuropsychological tests (chi(2) = 8.22, df = 8, p = .41). No between-group differences were noted in symptom changes. Atomoxetine was well tolerated and was associated with a trend for improvement in extrapyramidal side effects relative to placebo (p = .063).

CONCLUSION

Our results provide further evidence that atomoxetine has limited benefit for improving cognition in people with schizophrenia.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00161031.

Dopamine transporter polymorphism modulates oculomotor function and DAT1 mRNA expression in schizophrenia

Smooth pursuit eye movement (SPEM) deficit is an established schizophrenia endophenotype with a similar neurocognitive construct to working memory. Frontal eye field (FEF) neurons controlling SPEM maintain firing when visual sensory information is removed, and their firing rates directly correlate with SPEM velocity. We previously demonstrated a paradoxical association between a functional polymorphism of dopamine signaling (COMT gene) and SPEM. Recent evidence implicates the dopamine transporter gene (DAT1) in modulating cortical dopamine and associated neurocognitive functions. We hypothesized that DAT1 10/10 genotype, which reduces dopamine transporter expression and increases extracellular dopamine, would affect SPEM. We examined the effects of DAT1 genotype on: Clinical diagnosis in the study sample (n = 418; 190 with schizophrenia), SPEM measures in a subgroup with completed oculomotor measures (n = 200; 87 schizophrenia), and DAT1 gene expression in FEF tissue obtained from postmortem brain samples (n = 32; 16 schizophrenia). DAT1 genotype was not associated with schizophrenia. DAT1 10/10 genotype was associated with better SPEM in healthy controls, intermediate SPEM in unaffected first-degree relatives of schizophrenia subjects, and worse SPEM in schizophrenia subjects. In the gene expression study, DAT1 10/10 genotype was associated with significantly reduced DAT1 mRNA transcript in FEF tissue from healthy control donors (P < 0.05), but higher expression in schizophrenia donors. Findings suggest regulatory effects of another gene(s) or etiological factor in schizophrenia, which modulate DAT1 gene function.

Clinical and detailed angiographic findings in patients with ambulatory electrocardiographic ischemia without critical coronary narrowing: results from the Asymptomatic Cardiac Ischemia Pilot (ACIP) Study

BACKGROUND

Patients with ambulatory electrocardiographic (AECG) ST-segment depression and critical coronary narrowing are known to be at increased risk for adverse outcome, but little is known about patients with AECG ST-segment depression without critical coronary narrowing.

HYPOTHESIS

The objectives of this study were to characterize the coronary angiographic pathology in patients with AECG ST-segment depression but without critical (< 50% diameter stenosis) coronary narrowing and to compare demographic and clinical findings in these patients with those enrolled in the Asymptomatic Cardiac Ischemia Pilot Study with AECG ST-segment depression and critical (> or = 50% diameter stenosis) coronary narrowing.

METHODS

Coronary angiograms from patients with AECG ST-segment depression were reviewed in a central laboratory and quantitative measurement of percent stenosis was performed. Clinical and angiographic comparisons were made between patients with and without critical coronary narrowing.

RESULTS

Patients without critical coronary narrowing (n = 64) were younger (p = 0.02), less likely to be male (p < 0.001) or to have risk factors for coronary atherosclerosis or a history of myocardial infarction (p < 0.001), and had fewer ischemic episodes per 24 h on the screening AECG (p = 0.02) than patients with critical coronary narrowing (n = 441). Of patients without critical narrowing, one half had angiographic evidence for coronary artery disease (> or = 20% stenosis) and 60% had an ejection fraction > 70%.

CONCLUSIONS

Patients with AECG ST-segment depression without critical coronary narrowing are heterogeneous, with half having measurable coronary artery disease. Demographically and clinically, they appear to be different than patients with AECG ST-segment depression with critical coronary narrowing.

Set-shifting ability and schizophrenia: a marker of clinical illness or an intermediate phenotype?

BACKGROUND

Impairments of executive functioning, such as set-shifting ability, are seen as core deficits of schizophrenia and are of interest as candidate intermediate phenotype markers. The Intradimensional/Extradimensional (ID/ED) shift task offers a differentiated assessment of shifting from previously reinforced stimuli as well as shifting from previously reinforced features and has proven to be sensitive to the impairment seen in patients with schizophrenia.

METHODS

We examined ID/ED performance in 147 patients with schizophrenia, 131 of their healthy siblings, and 303 healthy control subjects. Participants were recruited from local and national sources as volunteers for the Clinical Brain Disorders Branch/National Institute of Mental Health "sibling study".

RESULTS

Nearly all control subjects (87%) finished the task successfully, as did 80% of siblings. In contrast only 54% of patients with schizophrenia were able to complete the task. Despite the apparent similarity of performance across the sibling and healthy comparison group, the two groups differed significantly in terms of the number of stages until failure. This difference, however, was not present at any particular stage or any other measure of performance.

CONCLUSIONS

Patients demonstrated robust ID/ED deficits. However, their siblings were minimally impaired, and this impairment did not seem to run in families. These results suggest that impairments on attentional set shifting assessed by ID/ED task are strongly associated with clinical illness, but these impairments are not a promising intermediate phenotype.

Sensory gating endophenotype based on its neural oscillatory pattern and heritability estimate

CONTEXT

The auditory sensory gating deficit has been considered a leading endophenotype in schizophrenia. However, the commonly used index of sensory gating, P50, has low heritability in families of people with schizophrenia, raising questions about its utility in genetic studies. We hypothesized that the sensory gating deficit may occur in a specific neuronal oscillatory frequency that reflects the underlying biological process of sensory gating. Frequency-specific sensory gating may be less complex than the P50 response, and therefore closer to the direct genetic effects, and thus a more valid endophenotype.

OBJECTIVES

To compare the gating of frequency-specific oscillatory responses with the gating of P50 and to compare their heritabilities.

DESIGN

We explored single trial-based oscillatory gating responses in people with schizophrenia, their relatives, and control participants from the community.

SETTING

Outpatient clinics.

PARTICIPANTS

Persons with schizophrenia (n = 102), their first-degree relatives (n = 74), and control participants from the community (n = 70).

MAIN OUTCOME MEASURES

Gating of frequency-specific oscillatory responses, gating of the P50 wave, and their heritability estimates.

RESULTS

Gating of the theta-alpha-band responses of the control participants were significantly different from those with schizophrenia (P < .001) and their first-degree relatives (P = .04 to .009). The heritability of theta-alpha-band gating was estimated to be between 0.49 and 0.83 and was at least 4-fold higher than the P50 heritability estimate.

CONCLUSIONS

Gating of the theta-alpha-frequency oscillatory signal in the paired-click paradigm is more strongly associated with schizophrenia and has significantly higher heritability compared with the traditional P50 gating. This measure may be better suited for genetic studies of the gating deficit in schizophrenia.

Lack of beneficial galantamine effect for smoking behavior: a double-blind randomized trial in people with schizophrenia

Cigarette smoking is in schizophrenia is prevalent and may be due to self-medicating attempts to improve cognitive deficits related to alpha7 and alpha4beta2 nicotinic receptor dysregulation. Galantamine is an acetylcholinesterase inhibitor that acts as a positive allosteric modulator of nicotine acetylcholine receptors including both the alpha4beta2 and alpha7 subunits. In a double-blind randomized clinical trial galantamine was compared to placebo for its effects on cognitive functioning in people with schizophrenia. This manuscript reports findings for galantamine's effect on smoking behavior in people from this 12-week trial who were smokers (18 galantamine, 25 placebo). Expired CO was measured every 2 weeks and the Fagerström Test for Nicotine Dependence (FTND) was administered at baseline and endpoint. Expired CO measures in galantamine subjects were 23.0+/-9.7 ppm and 21.1+/-10.3 ppm at baseline and Week 12, respectively, compared to 20.1+/-8.5 ppm and 21.0+/-10.3 ppm at baseline and Week 12 in placebo subjects. The mean tau-b correlation between expired CO level and visit was -0.05+/-0.41 in the galantamine group and 0.13+/-0.42 in the placebo group (F=0.73, df=1,38, p=0.40), suggesting that there were no trends toward increased or decreased smoking in either group. Mean FTND scores in the galantamine group were 4.9+/-2.5 at baseline and 5.2+/-2.2 at Week 12, compared to 4.1+/-2.6 at baseline and 3.7+/-2.6 at Week 12 in the placebo group (Mantel-Haenszel chi2=5.53, df=1, p=0.019), for an effect size of 0.4. These results suggest that galantamine has no effect on cigarette smoking and that during galantamine treatment nicotine dependency scores worsen.