Implications for Atypical Antipsychotics in the Treatment of Schizophrenia: Neurocognition Effects and a Neuroprotective Hypothesis

Validity and reliability of a Chinese version of the self-evaluation of negative symptoms

The negative symptoms of schizophrenia can be present at any clinical stage, but evaluating the negative symptoms always remains challenging. To screen the negative symptoms effectively, self-evaluation should be introduced. To date, professional psychiatrists used almost all of the scales available to screen the negative symptoms but could not obtain an accurate outcome. At the same time, an advanced self-assessment scale is needed to accompany the patients' self-feeling-based treatment strategies to understand their feelings about their symptoms. Hence, Chinese self-evaluation of negative symptoms (SNS) should be introduced in China. This study aims to examine the validity and reliability of the Chinese version of SNS. Two hundred patients with schizophrenia were included in this study and were evaluated entirely with the self-assessed negative symptoms by the Chinese version. The correlation analysis was performed between SNS and the Scale for Assessment of Negative Symptoms (SANS) to assess the criterion validity of SNS for screening negative symptoms. Exploratory factor analysis was used to determine the constructive validity of the SNS. Two senior professional psychiatrists were involved in this assessment based on their clinical experience and capability to define the severity of the negative symptoms. Receiver operating characteristic curve (ROC) analysis was performed to assess the cutoff point of SNS. Cronbach's alpha coefficient and intraclass correlation (ICC) coefficient were used to determine the reliability of SNS. We have the following findings: The Chinese version of SNS demonstrated a significant correlation with the SANS (r = .774, p < .05). Exploratory factor analysis demonstrated that the factor loading varies from .442 to .788. ROC analysis demonstrated that at SNS ≥ 8, the patients demonstrated a mild severity of negative symptoms, and at SNS ≥ 15, the patients demonstrated a severe severity of negative symptoms. Subsequently, 9 < SNS < 14 was defined as a moderate severity of negative symptoms. The Cronbach's alpha and ICC coefficients of the Chinese version SNS were .877 and .774, respectively. Our results showed that the acceptable validity and reliability of the Chinese version of SNS confirmed that SNS is an ideal tool for self-assessment of the negative symptoms in patients with schizophrenia.

Cognitive Rehabilitation in Schizophrenia-Associated Cognitive Impairment: A Review

Patients suffering from schizophrenia often experience cognitive disturbances. Cognitive rehabilitation-computerized or non-computerized-is widely known as an alternative way to enhance cognitive functioning in patients with schizophrenia. The aim of the present review was to examine the role of cognitive rehabilitation (both computerized and non-computerized) for the alleviation of cognitive impairment in schizophrenia patients. Fourteen relative studies were examined and included in the present review. The results revealed that both computerized and non-computerized cognitive rehabilitation could enhance cognitive functioning and more specifically memory, attention, executive functioning, processing speed and in a few cases, even non-cognitive impairments, such as other schizophrenia symptoms. The present results support the efficacy of cognitive rehabilitation in schizophrenia patients, regardless of whether it is computerized or non-computerized. As the randomized control trials (RCTs) are limited in number, there is urgent need for more RCTs and longitudinal studies combining different kinds of interventions, as well as systematic reviews and meta-analyses, in order to further investigate and confirm the current results.

Antioxidant Properties of Second-Generation Antipsychotics: Focus on Microglia

Recent studies suggest a primary role of oxidative stress in an early phase of the pathogenesis of schizophrenia and a strong neurobiological link has been found between dopaminergic system dysfunction, microglia overactivation, and oxidative stress. Different risk factors for schizophrenia increase oxidative stress phenomena raising the risk of developing psychosis. Oxidative stress induced by first-generation antipsychotics such as haloperidol significantly contributes to the development of extrapyramidal side effects. Haloperidol also exerts neurotoxic effects by decreasing antioxidant enzyme levels then worsening pro-oxidant events. Opposite to haloperidol, second-generation antipsychotics (or atypical antipsychotics) such as risperidone, clozapine, and olanzapine exert a strong antioxidant activity in experimental models of schizophrenia by rescuing the antioxidant system, with an increase in superoxide dismutase and glutathione (GSH) serum levels. Second-generation antipsychotics also improve the antioxidant status and reduce lipid peroxidation in schizophrenic patients. Interestingly, second-generation antipsychotics, such as risperidone, paliperidone, and in particular clozapine, reduce oxidative stress induced by microglia overactivation, decreasing the production of microglia-derived free radicals, finally protecting neurons against microglia-induced oxidative stress. Further, long-term clinical studies are needed to better understand the link between oxidative stress and the clinical response to antipsychotic drugs and the therapeutic potential of antioxidants to increase the response to antipsychotics.

Antipsychotics, Metabolic Adverse Effects, and Cognitive Function in Schizophrenia

Cognitive impairment is a core symptom domain of schizophrenia. The effect of antipsychotics, the cornerstone of treatment in schizophrenia, on this domain is not fully clear. There is some evidence suggesting that antipsychotics may partially improve cognitive function, and that this improvement may vary depending on the specific cognitive domain. However, this research is confounded by various factors, such as age, duration/stage of illness, medication adherence, and extrapyramidal side effects that complicate the relationship between antipsychotics and cognitive improvement. Furthermore, antipsychotics-particularly the second generation, or "atypical" antipsychotics-can induce serious metabolic side effects, such as obesity, dyslipidemia and type 2 diabetes, illnesses which themselves have been linked to impairments in cognition. Thus, the inter-relationships between cognition and metabolic side effects are complex, and this review aims to examine them in the context of schizophrenia and antipsychotic treatment. The review also speculates on potential mechanisms underlying cognitive functioning and metabolic risk in schizophrenia. We conclude that the available literature examining the inter-section of antipsychotics, cognition, and metabolic effects in schizophrenia is sparse, but suggests a relationship between metabolic comorbidity and worse cognitive function in patients with schizophrenia. Further research is required to determine if there is a causal connection between the well-recognized metabolic adverse effects of antipsychotics and cognitive deficits over the course of the illness of schizophrenia, as well as, to determine underlying mechanisms. In addition, findings from this review highlight the importance of monitoring metabolic disturbances in parallel with cognition, as well as, the importance of interventions to minimize metabolic abnormalities for both physical and cognitive health.

Brain Sub/Region-Specific Effects of Olanzapine on c-Fos Expression of Chronically Socially Isolated Rats

Olanzapine (Olz) is an atypical antipsychotic used to treat depression, anxiety and schizophrenia, which can be caused by chronic psychosocial stress. c-Fos protein expression has been used as an indirect marker of neuronal activity in response to various forms of stress or pharmacological treatments. We examined the effects of a 3-week treatment of Olz (7.5 mg/kg/day) on c-Fos protein expression in stress-relevant brain sub/regions, its relationship with isolation-induced behavioral changes, and potential sites of Olz action on control and male rats exposed to 6 weeks of chronic social isolation (CSIS), an animal model of depression. Olz treatment reversed depression- and anxiety-like behaviors induced by CSIS and suppressed a CSIS-induced increase in the number of c-Fos-positive cells in subregions of the dorsal hippocampus, ventral (v) DG, retrosplenial cortex, and medial prefrontal cortex. In contrast, no change in c-Fos expression was seen in the CA3v, amygdala and thalamic, hypothalamic or striatal subregions in Olz-treated CSIS rats, suggesting different brain sub/regions' susceptibility to Olz. An increased number of c-Fos-positive cells in the CA1v, amygdala and thalamic, hypothalamic and striatal subregions in controls as well as in the CA1v and subregion of the hypothalamus and nucleus accumbens in Olz-treated CSIS rats was found. Results suggest the activation of brain sub/regions following CSIS that may be involved in depressive and anxiety-like behaviors. Olz treatment showed region-specific effects on neuronal activation. Our data contribute to a better understanding of the mechanisms underlying the CSIS response and potential brain targets of Olz in socially isolated rats.

Overexpression of Insig-2 inhibits atypical antipsychotic-induced adipogenic differentiation and lipid biosynthesis in adipose-derived stem cells

Atypical antipsychotics (AAPs) are considered to possess superior efficacy for treating both the positive and negative symptoms of schizophrenia; however, AAP use often causes excessive weight gain and metabolic abnormalities. Recently, several reports have demonstrated that AAPs activate sterol regulatory element-binding protein (SREBP). SREBP, SREBP cleavage-activating protein (SCAP) and insulin-induced gene (Insig) regulate downstream cholesterol and fatty acid biosynthesis. In this study, we explored the effects of clozapine, olanzapine and risperidone on SREBP signaling and downstream lipid biosynthesis genes in the early events of adipogenic differentiation in adipose-derived stem cells (ASCs). After the induction of adipogenic differentiation for 2 days, all AAPs, notably clozapine treatment for 3 and 7 days, enhanced the expression of SREBP-1 and its downstream lipid biosynthesis genes without dexamethasone and insulin supplementation. Simultaneously, protein level of SREBP-1 was significantly enhanced via inhibition of Insig-2 expression. By contrast, SREBP-1 activation was suppressed when Insig-2 expression was upregulated by transfection with Insig-2 plasmid DNA. In summary, our results indicate that AAP treatment, notably clozapine treatment, induces early-stage lipid biosynthesis in ASCs. Such abnormal lipogenesis can be reversed when Insig-2 expression was increased, suggesting that Insig/SCAP/SREBP signaling may be a therapeutic target for AAP-induced weight gain and metabolic abnormalities.

Olanzapine: a 5-year perspective

Olanzapine is a novel antipsychotic, approved for the acute and maintenance treatment of schizophrenia and bipolar I disorder. Despite the publicity regarding reported adverse events with the novel antipsychotics, such as weight gain and Type II diabetes mellitus, olanzapine remains a useful and important medicine. It is a selective monoaminergic antagonist with high-affinity binding to a number of receptors thought to be implicated in some psychotic and mood symptoms. The complex pharmacology of olanzapine has lead to studies exploring its use in treating substance abuse, aggression/violence, borderline personality disorder, schizotypal personality disorder, obsessive-compulsive disorder and as a neuroprotective agent in schizophrenia. As the pharmacology of olanzapine and other novel antipsychotics becomes better understood, future effective treatment strategies are likely to match an individual's genetic makeup and receptor profiles to the most compatible agent.

Vascular endothelial growth factor and brain-derived neurotrophic factor in quetiapine treated first-episode psychosis

Objective. It has been suggested that atypical antipsychotics confer their effects via brain-derived neurotrophic factor (BDNF). We investigated the effect of quetiapine on serum levels of BDNF and vascular endothelial growth factor (VEGF) in drug-naive first-episode psychosis subjects. Methods. Fifteen patients drawn from a larger study received quetiapine treatment for twelve weeks. Baseline levels of serum BDNF and VEGF were compared to age- and sex-matched healthy controls and to levels following treatment. Linear regression analyses were performed to determine the relationship of BDNF and VEGF levels with outcome measures at baseline and week 12. Results. The mean serum BDNF level was significantly higher at week 12 compared to baseline and correlated with reductions in Brief Psychiatric Rating Scale (BPRS) and general psychopathology scores. Changes in serum VEGF levels also correlated significantly with a reduction in BPRS scores, a significant improvement in PANNS positive symptoms scores, and displayed a positive relationship with changes in BDNF levels. Conclusions. Our findings suggest that BDNF and VEGF are potential biomarkers for gauging improvement of psychotic symptoms. This suggests a novel neurotrophic-based mechanism of the drug effects of quetiapine on psychosis. This is the first report of VEGF perturbation in psychosis.

In vitro findings of alterations in intracellular calcium homeostasis in schizophrenia

The pathogenesis of schizophrenia involves several complex cellular mechanisms and is not well understood. Recent research has demonstrated an association between primary disturbances characteristic of the disease, including altered dopaminergic and glutamatergic neurotransmission, and impairments in neuronal calcium (Ca(2+)) homeostasis and signaling. Emerging Ca(2+) hypothesis links and unifies various cellular processes involved in the pathogenesis of schizophrenia and suggests a central role of dysregulation of Ca(2+) homeostasis in the etiology of the disease. This review explores the in vitro data on Ca(2+) homeostasis and signaling in schizophrenia. Major limitation in this research is the lack of schizophrenia markers and validated disease models. As indicated in this review, one way to overcome these limitations may be analyses of Ca(2+) signalosomes in peripheral cells from schizophrenia patients. Validation of animal models of schizophrenia may permit the application of advanced Ca(2+) imaging techniques in living animals.

Effects of atypical (risperidone) and typical (haloperidol) antipsychotic agents on astroglial functions

Although classical and atypical antipsychotics may have different neurotoxic effects, their underlying mechanisms remain to be elucidated, especially regarding neuroglial function. In the present study, we compared the atypical antipsychotic risperidone (0.01-10 μM) with the typical antipsychotic haloperidol (0.01-10 μM) regarding different aspects such as glutamate uptake, glutamine synthetase (GS) activity, glutathione (GSH) content, and intracellular reactive oxygen species (ROS) production in C6 astroglial cells. Risperidone significantly increased glutamate uptake (up to 27%), GS activity (14%), and GSH content (up to 17%). In contrast, haloperidol was not able to change any of these glial functions. However, at concentration of 10 μM, haloperidol increased (12%) ROS production. Our data contribute to the clarification of different hypothesis concerning the putative neural responses after stimulus with different antipsychotics, and may establish important insights about how brain rewiring could be enhanced.

Synthesis and in vitro and in vivo evaluation of 18F-labeled positron emission tomography (PET) ligands for imaging the vesicular acetylcholine transporter

A new class of vesicular acetylcholine transporter inhibitor that incorporates a carbonyl group into the benzovesamicol structure was synthesized, and analogues were evaluated in vitro. (+/-)-trans-2-Hydroxy-3-(4-(4-[(18)F]fluorobenzoyl)piperidino)tetralin (9e) has K(i) values of 2.70 nM for VAChT, 191 nM for sigma(1), and 251 nM for sigma(2). The racemic precursor (9d) was resolved via chiral HPLC, and (+/-)-[(18)F]9e, (-)-[(18)F]9e, and (+)-[(18)F]9e were respectively radiolabeled via microwave irradiation of the appropriate precursors with [(18)F]/F(-) and Kryptofix/K(2)CO(3) in DMSO with radiochemical yields of approximately 50-60% and specific activities of >2000 mCi/micromol. (-)-[(18)F]9e uptake in rat brain was consistent with in vivo selectivity for the VAChT with an initial uptake of 0.911 %ID/g in rat striatum and a striatum/cerebellum ratio of 1.88 at 30 min postinjection (p.i.). MicroPET imaging of macaques demonstrated a 2.1 ratio of (-)-[(18)F]9e in putamen versus cerebellum at 2 h p.i. (-)-[(18)F]9e has potential to be a PET tracer for clinical imaging of the VAChT.

Added ondansetron for stable schizophrenia: a double blind, placebo controlled trial

It is well documented that 5-hydroxytryptamine3 (5-HT3) receptors are involved in the pathogenesis of schizophrenia and cognitive impairment. The purpose of this study was to assess the efficacy of ondansetron, a 5-HT3 receptor antagonist as an adjuvant agent in the treatment of chronic schizophrenia in particular for cognitive impairments. This investigation was a 12-week, double blind study of parallel groups of patients with stable chronic schizophrenia. Thirty patients were recruited from inpatient and outpatient departments. All participants met Diagnostic and Statistical Manual of Mental Disorders Fourth Edition, Text Revision (DSM-IV-TR) criteria for schizophrenia. To be eligible, patients were required to have been treated with a stable dose of risperidone as their primary antipsychotic treatment for a minimum period of 8 weeks. The subjects were randomized to receive ondansetron (8 mg/day) or the placebo in addition to risperidone. Clinical psychopathology was assessed with Positive and Negative Syndrome Scale (PANSS). Cognition was measured by a cognitive battery. Patients were assessed at baseline and after 8, and 12 weeks after the medication started. The PANSS scores and cognitive performance were used as the outcome measures. The ondansetron group had significantly greater improvement in the negative symptoms, general psychopathological symptoms and PANSS total scores over the trial. Administration of ondansetron significantly improved visual memory based on improvement on visual reproduction, visual paired associate and figural memory sub tests of Wechsler Memory Scale--Revised. The present study indicates ondansetron as potential adjunctive treatment strategy for chronic schizophrenia particularly for negative symptoms and cognitive impairments.

Neuroprotective effect of atypical antipsychotics in cognitive and non-cognitive behavioral impairment in animal models

Antipsychotic drugs are divided into two groups: typical and atypical. Recent clinical studies show atypical antipsychotics have advantages over typical antipsychotics in a wide variety of neuropsychiatric conditions, in terms of greater efficacy for positive and negative symptoms, beneficial effects on cognitive functioning, and fewer extra pyramidal side effects in treating schizophrenia. As such, atypical antipsychotics may be effective in the treatment of depressive symptoms associated with psychotic and mood disorders, posttraumatic stress disorder and psychosis in Alzheimer disease. In this paper, we describe the effects and potential neurochemical mechanisms of action of atypical antipsychotics in several animal models showing memory impairments and/or non-cognitive behavioral changes. The data provide new insights into the mechanisms of action of atypical antipsychotics that may broaden their clinical applications.

A 12-week, double-blind, placebo-controlled trial of donepezil adjunctive treatment to risperidone in chronic and stable schizophrenia

There is considerable incentive to develop new treatment strategies that effectively target cognitive deficits in schizophrenia. One of the theoretically promising novel treatment candidates is acetylcholinesterase inhibitors that increase the synaptic levels of cholinergic, nicotinic, and muscarinic receptor activity. The purpose of this study was to assess the efficacy of donepezil as an adjuvant agent in the treatment of chronic schizophrenia in particular for cognitive impairments. This investigation was a 12-week, double-blind study of parallel groups of patients with stable chronic schizophrenia. Thirty patients were recruited from inpatient and outpatient departments, age ranging from 22 to 44 years. All participants met DSM-IV-TR. diagnostic criteria for schizophrenia. To be eligible, patients were required to have been treated with a stable dose of risperidone as their primary antipsychotic treatment for a minimum period of 8 weeks. The subjects were randomized to receive donepezil (10 mg/day) or placebo, in addition to risperidone (4-6 mg/day). Clinical psychopathology was assessed with Positive and Negative Syndrome Scale (PANSS). Cognition was measured by a cognitive battery. Patients were assessed by a psychiatrist at baseline and after 8, and 12 weeks after the medication started. The PANSS scores and cognitive performance were used as the outcome measures. The donepezil group had significantly greater improvement in the negative symptoms over the 12-week trial. There were no differences between the donepezil and placebo groups on any neurocognitive assessments at endpoint (week 12). The present study indicates donepezil as a potential adjunctive treatment strategy for negative symptoms of chronic schizophrenia.

Antipsychotic-induced tardive dyskinesia and polymorphic variations in COMT, DRD2, CYP1A2 and MnSOD genes: a meta-analysis of pharmacogenetic interactions

Despite accumulating evidence pointing to a genetic basis for tardive dyskinesia, results to date have been inconsistent owing to limited statistical power and limitations in molecular genetic methodology. A Medline, EMBASE and PsychINFO search for literature published between 1976 and June 2007 was performed, yielding 20 studies from which data were extracted for calculation of pooled estimates using meta-analytic techniques. Evidence from pooled data for genetic association with tardive dyskinesia (TD) showed (1) in COMT(val158met), using Val-Val homozygotes as reference category, a protective effect for Val-Met heterozygotes (OR=0.63, 95% CI: 0.46-0.86, P=0.004) and Met carriers (OR=0.66, 95% CI: 0.49-0.88, P=0.005); (2) in Taq1A in DRD2, using the A1 variant as reference category, a risk-increasing effect for the A2 variant (OR=1.30, 95% CI: 1.03-1.65, P=0.026), and A2-A2 homozygotes using A1-A1 as reference category (OR=1.80, 95% CI: 1.03-3.15, P=0.037); (3) in MnSOD Ala-9Val, using Ala-Ala homozygotes as reference category, a protective effect for Ala-Val (OR=0.37, 95% CI: 0.17-0.79, P=0.009) and for Val carriers (OR=0.49, 95% CI: 0.24-1.00, P=0.047). These analyses suggest multiple genetic influences on TD, indicative of pharmacogenetic interactions. Although associations are small, the effects underlying them may be subject to interactions with other loci that, when identified, may have acceptable predictive power. Future genetic research will take advantage of new genomic knowledge. Molecular Psychiatry (2008) 13, 544-556; doi:10.1038/sj.mp.4002142; published online 8 January 2008.

Differential effects of classical and atypical antipsychotic drugs on rotenone-induced neurotoxicity in PC12 cells

Although classical and atypical antipsychotics may have different effects against neurotoxicity, the underlying mechanisms remain to be elucidated. In the present study, we compared the atypical agents, risperidone (RIP), olanzapine (OLZ), and quetiapine (QTP), with the classical agent haloperidol (HAL) in reducing cytotoxicity induced by rotenone, a mitochondrial complex I inhibitor, in PC12 cells. We also determined whether there were differential effects of RIP and HAL on the expression of brain-derived neurotrophic factor (BDNF), signal transducers and activators of transcription-3 (STAT-3), and the immediate early gene c-fos, as well as intracellular levels of calcium. Exposure to 6 muM rotenone for 24 h resulted in a significant decrease in cell viability and apoptotic alteration. The rotenone-induced cytotoxicity was dose-dependently worsened by pretreatment with HAL, but significantly improved by the aforementioned atypical agents at low doses. Real-time PCR analysis revealed that HAL pretreatment significantly increased BDNF mRNA expression but did not alter c-fos and STAT-3 expression compared to rotenone-exposed cells. Unlike HAL, RIP pretreatment produced a significant elevation of all the three substance mRNA expression and the expression intensity was 2.6- to 4.6-fold greater than HAL. Pretreatment with RIP, but not HAL, also effectively prevented an elevation of intracellular levels of calcium provoked by rotenone. These results suggest that the protective effects of atypical antipsychotics are associated with a greater capacity to enhance pro-cell survival factors, therapeutic biomarker expression, and blockade of calcium influx. This may provide an alternative for explaining therapeutic advantages of atypical agents observed in clinical use.

Treatment of cognitive deficits associated with schizophrenia: potential role of catechol-O-methyltransferase inhibitors

In the last two decades, understanding of the dynamics of dopamine function in the prefrontal cortex and its role in prefrontal cortex physiology has opened up new avenues for therapeutic interventions in conditions in which prefrontal cortex function is compromised. Neuropsychological and imaging studies of prefrontal information processing have confirmed specific cognitive and neurophysiological abnormalities in individuals with schizophrenia. Because such findings are also observed in the healthy siblings of patients with schizophrenia, they may represent intermediate phenotypes related to schizophrenia susceptibility genes.Catechol-O-methyltransferase (COMT) represents an important candidate as a susceptibility gene for cognitive dysfunction in schizophrenia because of the unique role this enzyme plays in regulating prefrontal dopaminergic function. A functional COMT polymorphism (Val158Met) predicts performance in tasks of prefrontal executive function and the neurophysiological response measured with electroencephalography and functional magnetic resonance imaging in tasks assessing working memory. In fact, individuals with the Val/Val genotype, which encodes for the high-activity enzyme resulting in lower dopamine concentrations in the prefrontal cortex, perform less well and are less efficient physiologically than Met/Met individuals. These findings raise the possibility of new pharmacological interventions for the treatment of prefrontal cortex dysfunction and of predicting outcome based on COMT genotype. One strategy consists of the use of CNS-penetrant COMT inhibitors such as tolcapone. A second strategy is to increase extracellular dopamine concentrations in the frontal cortex by blocking the noradrenaline (norepinephrine) reuptake system, a secondary mechanism responsible for the disposal of dopamine from synaptic clefts in the prefrontal cortex. A third possibility involves the use of modafinil, a drug with an unclear mechanism of action but with positive effects on working memory in rodents. The potential of these drugs to improve executive cognitive function by selectively increasing dopamine load in the frontal cortex but not in subcortical territories, and the possibility that response to them may be modified by a COMT polymorphism, provides a novel genotype-based targeted pharmacological approach without abuse potential for the treatment of cognitive disorder in schizophrenia and in other conditions involving prefrontal cortex dysfunction.

Long-term outcomes in chronically hospitalized geriatric patients with schizophrenia: retrospective comparison of first generation and second generation antipsychotics

INTRODUCTION

Some groups have reported the longitudinal course of elderly poor outcome schizophrenic patients to be characterized by progressive decline in cognitive functions and functional capacity. Although many of these patients experience minimal reduction of psychotic symptoms, there may be beneficial effects of antipsychotic treatments on cognitive functions and functional capacity.

METHODS

This naturalistic study compared the longitudinal course of psychotic symptoms, cognitive functions and functional impairment in geriatric schizophrenic patients treated with first generation (N=97) or second generation (N=78) antipsychotic medications. Mixed effects linear regression analyses were used to examine the effects of treatment (first generation vs. second generation antipsychotic), time and treatment x time.

RESULTS

Cognitive functions (Mini Mental State Examination time effect estimate=-.41, p<.001; ADAS-L Cog time effect estimate=.64, p<.001) and self-care skills (ADAS-L Self-Care time effect estimate=.65, p<.001) declined over time for the subject group as a whole and this decline was not modified by treatment with second generation antipsychotics relative to first generation antipsychotics. Similarly, second generation antipsychotic treatment produced no effect on the progressive worsening of negative symptom over time.

CONCLUSION

This long-term naturalistic study of poor outcome geriatric patients with schizophrenia did not find atypical antipsychotics to produce any differential protective effect relative to typical antipsychotics on the long-term manifestations of symptoms, cognition and self-care in poor outcome geriatric schizophrenic patients.

Symptom domains of schizophrenia: the role of atypical antipsychotic agents

Given their more obvious presentation, the reduction of positive symptoms and their associated behavioural problems have been considered the most important treatment outcome parameter in patients with schizophrenia. However, the development of the atypical antipsychotic agents in the early 1990s resulted in the adoption of more wide-reaching measures of therapeutic outcome. The aim of this review was to evaluate the efficacy of currently available atypical agents across multiple symptom domains of schizophrenia with a specific focus on negative symptoms, neurocognition, social functioning, quality of life and insight. As such, studies published between January 1990 and December 2005 that evaluated the clinical efficacy and tolerability of atypical antipsychotics in different symptom domains of schizophrenia were reviewed as identified from literature researches using MEDLINE and Embase. Abstracts and posters presented at key psychiatry and schizophrenia congresses during this period were also reviewed where available in the public domain. Results from the studies identified have consistently demonstrated that atypical antipsychotics have substantial advantages over conventional antipsychotics with a broader spectrum of efficacy across symptomatic domains of schizophrenia as proven by greater improvements in negative symptoms and cognitive function and a beneficial effect on affective symptoms and quality of life. However, their clinical advantages have often been limited by patients' partial compliance with therapy. As such, the development of a long-acting atypical antipsychotic agent may provide a new and valuable treatment option for patients with schizophrenia.

A neuropsychological study of patients with temporal lobe epilepsy and chronic interictal psychosis

PURPOSE

To characterize the pattern of cognitive deficits in patients with temporal lobe epilepsy (TLE) and interictal (schizophrenia-like) psychosis and to examine the relationship between neuropsychological deficits and Magnetization transfer imaging.

METHODS

Twenty patients with TLE and interictal psychosis were compared to 20 non-psychotic TLE patients. Patients were matched with respect to premorbid IQ, age and conventional MRI findings. A battery of neuropsychological tests was administered. The neuropsychological tests which showed significant group differences were used for correlational analysis with magnetization transfer ratio (MTR) which provides a quantitative measure of macromolecular structural integrity.

RESULTS

Patients with interictal psychosis were significantly more impaired on executive and semantic memory tasks than the non-psychotic TLE group. Vocabulary test scores correlated significantly with MTR reduction in the left fusiform gyrus in the psychotic but not the non-psychotic group.

DISCUSSION

In this study, patients with TLE and interictal psychosis were more cognitively impaired than non-psychotic TLE patients. Our findings suggest that the cognitive deterioration in these patients may occur as the illness progresses and the causes for this are probably multifactorial. Our study also provides further evidence that MTR may be useful in investigating structural correlates of cognitive impairment.

Reliability and validity of communication skills questionnaire (CSQ)

A new and easy evaluation method of communication skills has been developed using the Communication Skills Questionnaire (CSQ), which can be self-administered or administered by family members and medical staff. The reliability and validity of this CSQ were evaluated. Eighty-seven patients with mental disorders and 100 normal controls participated in a self-rating evaluation of the CSQ, and 55 family members and four medical personnel also participated in objective rating. The CSQ contained 29 items and these items were divided into three categories: cooperative skills (17 items), assertive skills (six items) and general communication skills (six items, mainly non-verbal skills). Internal consistencies of all groups were between 0.91 and 0.97. Test-retest reliability values for patients, family members and medical staff were between 0.90 and 0.95. Interrater reliability of medical staff was 0.73. The total scores had a moderate positive correlation with Global Assessment of Functioning (GAF) score and doctor's impression of communication skill evaluated on a 10-point scale. The patient group had a lower CSQ score than that of controls and the score differences between controls and patients with schizophrenia, mood disorders or eating disorders were statistically significant. This questionnaire is a good psychometric method of evaluating the communication skills of patients.

Molecular mapping of striatal subdivisions in juvenile Macaca Mulata

The striatum of the primate brain can be subdivided into three distinct anatomical subregions: caudate (CAU), putamen (PUT), and ventral striatum (VS). Although these subregions share several anatomical connections, cell morphological, and histochemical features, they differ considerably in their vulnerability to different neurological and psychiatric diseases, and these brain regions have significantly different functions in health and disease. In order to better understand the molecular underpinnings of the different disease and functional vulnerabilities, transcriptional profiles were generated from the CAU, PUT, and VS of five juvenile rhesus macaques (Macaca mulatta) using human cDNA neuromicroarrays containing triplicate spots of 1227 cDNAs. Differences in microarray gene expression were assessed using z score analysis and 1.5-fold change between paired subregions. Clustering of genes based on dissimilarity of expression patterns between regions revealed subregion specific expression profiles encoding G-protein-coupled receptor signaling transcripts, transcription factors, kinases and phosphatases, and cell signaling and signal transduction transcripts. Twelve transcripts were examined using quantitative real-time PCR (qPCR), and 81% demonstrated alterations similar to those seen with microarray analysis, some of which were statistically significant. Subregion specific transcription profiles support the anatomical differentiation and potential disease vulnerabilities of the respective subregions.

Pharmacological treatment to augment hole board habituation in prenatal Vitamin D-deficient rats

Neurocognitive impairment has consistently been considered a central and stable feature of schizophrenia. There is much controversy about the effects of neuroleptics on neurocognitive deficits. Thus, further investigations are needed to clarify the pathological substrate of cognitive deficits in schizophrenia as well as to identify pharmacological tools for treatment. Transient prenatal Vitamin D deficiency is considered a developmental model in schizophrenia research. Recently, it was reported that prenatal Vitamin D-depleted rats showed a habituation deficit in the hole board. Here, we tested the effect on hole board habituation of haloperidol (Hal, 0.075 mg/kg, i.p.), risperidone (Ris, 0.2 mg/kg, i.p.) and the mGluR5 agonist CHPG (0.1 mg, i.c.v.) after subchronic treatment. Hal was found to impair habituation in control animals, Ris restored hole board habituation, whereas Hal and CHPG normalised hole board habituation in the deplete animals completely. The results of the study demonstrate that (i) the Vitamin D model might be a valuable tool in the study of neurodevelopmental aspects of schizophrenia, (ii) the model is sensitive in detecting the effect of antipsychotic drugs and (iii) the model appears to be sensitive in differentiating between typical and atypical antipsychotic drug.

Quetiapine reverses the suppression of hippocampal neurogenesis caused by repeated restraint stress

Quetiapine is an atypical antipsychotic effective in treating the positive, negative, and cognitive symptoms of patients with schizophrenia. Our previous study has shown that chronic administration of quetiapine attenuates the decrease in levels of brain-derived neurotrophic factor (BDNF) in the hippocampi of rats subjected to chronic-restraint stress. In the present study, we investigated the effects of quetiapine on hippocampal neurogenesis that had been compromised in stressed rats. Newborn cells in the hippocampus were labeled by bromodeoxyuridine (BrdU), and immature neurons were detected immunohistochemically using an antibody against phosphorylated cAMP response element-binding protein (pCREB). The restrained rats (4 h/day for 7 days) showed lower levels of hippocampal neurogenesis indicated by decreased numbers of BrdU-labeled and pCREB-positive cells. Post-stress administration of quetiapine (10 mg/kg) for 7 or 21 days reversed the stress-induced suppression of hippocampal neurogenesis, evidenced in the numbers of BrdU-labeled and pCREB-positive cells that are comparable to those in non-stressed rats but higher than those in the vehicle-treated rats. The results may help us understand the therapeutic effects of quetiapine on cognitive deficits in patients with schizophrenia and depression, in which the structure and functions of the hippocampus are implicated.

Validation of the Investigator's Assessment Questionnaire, a new clinical tool for relative assessment of response to antipsychotics in patients with schizophrenia and schizoaffective disorder

The success of long-term therapy in schizophrenia is contingent upon real-world effectiveness or improvements in several domains, including efficacy, safety and tolerability. This report describes the Investigator's Assessment Questionnaire (IAQ), a new 10-item instrument designed to assess relative effectiveness (efficacy, safety and tolerability) of antipsychotic medications in patients with schizophrenia or schizoaffective disorder. To measure content validity, 300 psychiatrists rated the importance of the IAQ items. Efficacy (i.e., positive and negative symptoms) was considered most important, but importance scores relative to the mean ranged only from 0.87 to 1.18, suggesting similar importance of the items. Cronbach's coefficient alpha values showed that the items were internally consistent. Factor analyses indicated that all IAQ items belong to a single domain. Data from the US Broad Effectiveness Trial of Aripiprazole were used for construct validation. Total IAQ score correlated significantly with time to treatment discontinuation (r=-0.50), Clinical Global Impressions-Improvement (CGI-I) score (r=0.76) and medication preference of patients (r=0.71) or caregivers (r=0.70). A one-unit decrease in IAQ score corresponded to an additional 1.35 days in the study and a decrease in CGI-I of 0.21 units. These results provide initial validation of the IAQ as a tool for evaluating antipsychotic response in patients with schizophrenia or schizoaffective disorder.