Improvement in cognition associated with novel antipsychotic drugs: a direct drug effect or reduction of EPS?

Clozapine augmentation with cariprazine for negative symptoms: a case series and literature review

Only about 50% of patients with treatment-resistant schizophrenia respond to clozapine, and many more patients continue to experience ongoing and prominent negative symptoms. These negative symptoms, for which there are limited pharmacological options, may represent the greatest barrier to functional recovery. Cariprazine is a novel antipsychotic drug that is a partial agonist at dopamine D₂ and D₃ receptors with preferential binding to the D₃ receptor, antagonism of 5HT_2B receptors, and partial agonism at 5HT_1A receptors. Cariprazine is currently licenced for the treatment of schizophrenia in Europe and the United States and has also been approved for bipolar disorder in the United States. There is a limited body of evidence to suggest clinical effectiveness as an augmentation strategy for negative symptoms in those treated with clozapine. In this case series, we present five cases of successful treatment of negative symptoms by clozapine combined with cariprazine in treatment-resistant psychosis.

The Visuo-Motor Attention Test in Boys with Attention Deficit Hyperactivity Disorder (ADHD): Methylphenidate-Placebo Randomized Controlled Trial

To assess the visuomotor attention ability in children with ADHD and controls and their response to placebo and Methylphenidate (MPH) treatment. 36 boys with ADHD and 36 age matched typical controls were administered the visuomotor attention test (VMAT) as a baseline and following a week of MPH(IR) or placebo administered to the study group, in a randomized crossover design. A significant difference between the study and control groups was found on several VMAT measures. No performance difference between ADHD dimensional sub-types was observed at the baseline assessment. Under MPH treatment a significant improvement in VMAT measures was observed and particularly in the combined and predominantly hyperactive (C\HI) type. The VMAT results obtained in the present study are consistent with previous findings. ADHD subtypes appear similarly short of visuomotor attention resources; a visuomotor test can be used in the assessment of gains derived from MPH treatment.

A randomized controlled trial of olanzapine improving memory deficits in Han Chinese patients with first-episode schizophrenia

Olanzapine is an atypical antipsychotic for the treatment of schizophrenia, in which memory impairment is a core deficit. The methods of positive and negative syndrome scale (PANSS), Wechsler memory scale-4th edition (WMS-IV) and event-related potential (ERP) were used to study the effects of olanzapine on the cognitive function in the first-episode schizophrenic patients. We performed multicentre, randomized, double-blind, placebo-controlled, parallel-group clinical trial to study the cognitive functioning in Han Chinese first-episode schizophrenic patients in a 12-week treatment regime with olanzapine (129 cases) or placebo (132 cases). The results showed that (1) the patients with first-episode schizophrenia showed significant deficits in the long-term memory, short-term memory, immediate memory and memory quotient by WMS-IV assessment, and decreases the total scores, positive symptoms, negative symptoms and general psychopathology by PANSS assessment; (2) olanzapine could significantly improve the PANSS scores including total scores, positive symptoms, negative symptoms and general psychopathology in the first-episode schizophrenic patients; (3) olanzapine could significantly improve the short-term memory, immediate memory and memory quotient in the first-episode schizophrenic patients; and (3) although the latencies of P(2), N(2) and P(3) were significantly prolonged, P(2) and P(3) amplitudes were decreased and the latencies of N(1) did not change, olanzapine did not influence any P(300) items in the first-episode schizophrenic patients. The data suggested that that olanzapine could improve cognitive process, such as memorizing and extraction of the information although there were many changes of cognitive functions in Han Chinese first-episode schizophrenic patients.

HT1001, a proprietary North American ginseng extract, improves working memory in schizophrenia: a double-blind, placebo-controlled study

Evidence suggests that HT1001™, a proprietary North American ginseng extract containing known levels of active ginsenosides, may improve cognitive function. Importantly, individuals with schizophrenia show marked deficits in working memory, which are believed to be predictive of functional outcome in this population. The present study aimed to characterize the effect of HT1001 on working memory in a group of stable individuals with schizophrenia. In a double-blind, placebo-controlled study design, a total of 64 individuals satisfying DSM-IV criteria for schizophrenia were randomly assigned to receive either HT100 or placebo for 4 weeks. Verbal working memory and visual working memory were assessed at baseline and again at the end of the treatment phase using the Letter-Number Span Test and Visual Pattern Test, respectively. Symptoms and medication side effects were also measured at baseline and post-treatment. Visual working memory was significantly improved in the HT1001 group, but not in the placebo group. Furthermore, extrapyramidal symptoms were significantly reduced after 4 weeks treatment with HT1001, whereas no difference in extrapyramidal effects was observed in the placebo group. These results provide a solid foundation for the further investigation of HT1001 as an adjunct therapy in schizophrenia, as an improvement in working memory and a reduction in medication-related side effects has considerable potential to improve functional outcome in this population.

Cognitive efficacy of quetiapine and olanzapine in early-onset first-episode psychosis

The primary purpose of this study was to compare changes in cognition in early-onset psychosis after 6-months treatment with quetiapine or olanzapine. This is a randomized, single-blind, 6-month study in 50 adolescents with a diagnosis of early-onset psychosis. Patients were randomized to quetiapine (n = 24) or olanzapine (n =26). A thorough neuropsychological battery was administered at baseline and after 6-month treatment. Out of the total sample included in the study, 32 patients completed at least 6-months treatment with the assigned medication (quetiapine, n =16; olanzapine, n = 16). No changes were observed in cognitive performance after 6-month treatment with quetiapine or olanzapine. Although some trends toward cognitive improvement were observed for the olanzapine group after 6-month treatment, neither group showed statistically significant gains. Furthermore, there was no evidence of any differential efficacy of olanzapine or quetiapine on cognitive improvement in this sample of adolescents with psychosis.

Disruption of performance in the five-choice serial reaction time task induced by administration of N-methyl-D-aspartate receptor antagonists: relevance to cognitive dysfunction in schizophrenia

Schizophrenia patients suffer from cognitive impairments that are not satisfactorily treated by currently available medications. Cognitive dysfunction in schizophrenia encompasses deficits in several cognitive modalities that can be differentially responsive to different medications and are likely to be mediated by different neurobiological substrates. Translational animal models of cognitive deficits with relevance to schizophrenia are critical for gaining insights into the mechanisms underlying these impairments and developing more effective treatments. The five-choice serial reaction time task (5-CSRTT) is a cognitive task used in rodents that allows simultaneous assessment of several cognitive modalities, including attention, response inhibition, cognitive flexibility, and processing speed. Administration of N-methyl-D-aspartate (NMDA) glutamate receptor antagonists disrupts multiple 5-CSRTT performance measures in a way that mirrors various cognitive deficits exhibited by schizophrenia patients. Some of these disruptions are partially attenuated by antipsychotic medications that exhibit partial effectiveness on cognitive dysfunction in schizophrenia, suggesting that the model has predictive validity. Examination of the effects of pharmacological manipulations on 5-CSRTT performance disruptions induced by NMDA antagonists have implicated a range of brain regions, neurotransmitter systems, and specific receptor subtypes in schizophrenia-like impairment of different cognitive modalities. Thus, disruption of 5-CSRTT performance by NMDA antagonists represents a valuable tool for exploring the neurobiological bases of cognitive dysfunction in schizophrenia.

Neurocognitive costs and benefits of psychotropic medications in older adults

Psychotropic medications are widely used in older adults and may cause neurocognitive deficits. Older adults are at increased risk of developing adverse effects because of age-related pharmacodynamic and pharmacokinetic changes. This article provides a comprehensive review of the undesirable, and at times beneficial, effects of psychotropic medications. The review covers a wide range of medications that impair executive function, memory, and attention, as well as a much smaller group of medications that lead to improved neurocognitive function. Some of the most commonly used psychotropic medications in older adults, namely, antidepressants, sedatives, and hypnotics, are among the drugs that most consistently lead to cognitive impairments. Medications with anticholinergic properties almost invariably lead to neurocognitive dysfunction, despite symptom improvement. The neurocognitive costs and benefits of psychiatric medications should be considered in the context of disease treatment in older adults.

Effects of acute antipsychotic treatment on brain activation in first episode psychosis: an fMRI study

This study aimed to assess the neurophysiological effects of acute atypical antipsychotic treatment on cognitive functioning in subjects presenting with a first episode of psychosis. We used functional MRI to examine the modulatory effects of acute psychopharmacological intervention on brain activation during four different cognitive tasks: overt verbal fluency, random movement generation, n-back and a spatial object memory task. Treatment with atypical antipsychotics was associated with alterations in regional activation during each task and also when task demands were manipulated within paradigms. The initial treatment of psychosis with atypical antipsychotics thus appears to be associated with modifications of the neurofunctional correlates of executive and mnemonic functions. These effects need to be considered when interpreting group differences in activation between medicated patients and controls.

The effects of adulthood olanzapine treatment on cognitive performance and neurotrophic factor content in male and female rats neonatally treated with quinpirole

Male and female Sprague-Dawley rats were administered quinpirole (1 mg/kg, i.p.) or saline once daily from postnatal day (P)1 to P21. This drug treatment has been shown to produce long-term priming of the D2 receptor. Beginning on P62, rats were administered the atypical antipsychotic olanzapine (2.5 mg/kg) or saline twice daily (i.p.) for 28 days. One day after olanzapine treatment ceased, rats were tested on the place and match-to-place versions of the Morris water maze (MWM) for seven consecutive days. Dopamine D2 receptor priming was verified through a yawning behavioural test, a D2 receptor-mediated event, before olanzapine was administered as well as after olanzapine treatment and behavioural testing were complete. Results showed that neonatal quinpirole treatment induced D2 priming that was eliminated by olanzapine treatment. On the MWM place version, D2-primed rats demonstrated a significant impairment that was eliminated by olanzapine treatment, but olanzapine treatment to animals neonatally treated with saline produced a significant deficit on the place version of the MWM. There were no significant deficits on the match-to-place version. Brain tissue analyses revealed that neonatal quinpirole treatment produced a significant decrease in hippocampal NGF, BDNF and ChAT that was eliminated by olanzapine treatment. Neonatal quinpirole treatment produced a significant decrease in BDNF and ChAT in the frontal cortex that was unaffected by olanzapine treatment. These results show that olanzapine eliminates D2 receptor priming and cognitive impairment and also alleviates decreases in neurotrophins and acetylcholinergic markers produced by D2 priming in the hippocampus.

The impact of atypical antipsychotic medications on long-term memory dysfunction in schizophrenia spectrum disorder: a quantitative review

This meta-analytic review examines the efficacy of antipsychotic medications in ameliorating schizophrenia-related long-term memory (LTM) impairments. Twenty-three studies were reviewed that compared schizophrenia spectrum patients treated (a) with atypical versus typical antipsychotic medications, or (b) with various atypical treatments. In 17 atypical versus typical trials aggregating 939 participants, superior overall (verbal and nonverbal) LTM was detected in patients assigned to atypical trials. However, this difference was small (effect size estimate (ES) 0.17; 95% Confidence Interval (CI) 0.04 to 0.31) and specific to certain atypical treatments. Relative to typical antipsychotic trials, LTM superiority was marginally significant for risperidone trials (ES 0.20; 95% CI -0.03 to 0.44) and significant for olanzapine trials (ES 0.29; 95% CI 0.08 to 0.49). In contrast, clozapine trials did not produce a LTM advantage over typical trials (ES -0.06; 95% CI -0.35 to 0.23). Due to the lack of available studies, the effect of quetiapine was indeterminate. Direct comparison between atypical trials revealed a similar effect pattern. A marginally significant superiority in overall LTM was detected for risperidone and olanzapine compared to clozapine (ES 0.28; 95% CI -0.04 to 0.59), which reached significance for verbal LTM (ES 0.36; 95% CI 0.04 to 0.67). Finally, the beneficial impact of antipsychotic medications emerged as a function of differences in the anticholinergic properties of the treatment arms being compared.

Safety and tolerability of emerging pharmacological treatments for bipolar disorder

OBJECTIVES

Over the past few years numerous new agents have been examined for their efficacy in bipolar disorder (BPD). New antiepileptic agents and atypical antipsychotics currently form the bulk of these emerging agents. As the armamentarium for treating BPD increases, it allows for the possibility of choosing drugs on the basis of their tolerability as well as their efficacy, rather than on efficacy alone.

METHODS

Efficacy data for newer antiepileptic drugs (lamotrigine, topiramate, gabapentin, oxcarbazepine) and atypical antipsychotics (olanzapine, clozapine, risperidone, quetiapine, ziprasidone, aripiprazole) are briefly reviewed. The article focuses on relative safety and tolerability of these agents.

RESULTS

In general, most of these newer agents have better side effect and tolerability profiles than older agents commonly used to treat BPD (lithium, valproate, carbamazepine); however, these must be weighed against efficacy demonstrated to date in randomized, controlled trials. Cognitive impairment is a concern with topiramate, weight gain and risk of diabetes with some of the atypical antipsychotic agents, and rash with lamotrigine.

CONCLUSIONS

Side effects of newer emerging agents for the treatment of BPD can be effectively managed and the risks reduced by instituting practical strategies early in management.

Treatment of cognitive dysfunction in schizophrenia

BACKGROUND

Cognitive impairment has always been regarded as an important characteristic of schizophrenia. Many domains of cognition are disrupted with varying degrees of deficit: attention, executive functions, verbal and visuospatial working memory, learning, and memory. However, it is only recently that cognitive dysfunction has been recognized as a primary and enduring core deficit in schizophrenia (rather than the previous focus on positive and negative symptoms).

OBJECTIVE

This article discusses cognitive impairment and the therapeutic effects of newer antipsychotic agents on cognitive functioning in patients with schizophrenia.

CONCLUSIONS

Cognitive dysfunction occurs before the first psychotic episode and persists throughout the course of the illness. It involves every aspect of cognitive functioning and has an important impact on long-term social and occupational outcomes. Improvement of cognitive functioning by antipsychotic treatment can be due indirectly to the improvement of therapeutic profiles of the newer antipsychotic agents (eg, higher efficacy on positive and negative symptoms, fewer side effects, less anticholinergic effects) or directly to effects on cerebral functioning (eg, by restoring dopamine prefrontal activity). However, further research is needed regarding the therapeutic effects of the newer antipsychotic drugs on cognitive functioning and their impact on psychosocial outcome. Although newer medications may improve cognitive functioning, they do not normalize neurocognitive deficits in schizophrenia. In addition, various nonpharmacologic, psychological interventions have been used in the rehabilitation of patients with cognitive deficits.

A comparison of two novel antipsychotics in first episode non-affective psychosis: one-year outcome on symptoms, motor side effects and cognition

The main objective of this study was to compare 1-year outcome on symptoms, extrapyramidal side effects (EPS) , positive and negative symptoms, and domains of cognition in first episode psychosis (FEP) patients. Drug-naive FEP patients, who were similar on a number of characteristics likely to affect outcome, were treated with only one antipsychotic (risperidone or olanzapine) for at least 1 year and compared at baseline and after 1 year of treatment. Differences in outcome were assessed using an analysis of co-variance with change scores between initial assessment and after 1 year of treatment on levels of psychotic, disorganization and psychomotor poverty symptoms, EPS (parkinsonism, akathesia and dyskineisa) and domains of cognition as the dependent variable, respective baseline scores as covariates, and drug group as the independent variable. While patients in both groups showed substantial improvement, there were no significant differences in the magnitude of change in reality distortion, disorganization and psychomotor poverty symptoms. Trends in change in EPS favouring olanzapine and on some domains of cognition (processing speed and executive functions) favouring risperidone failed to reach statistical significance. The failure to confirm previous claims of greater improvement on either risperidone or olanzapine in patients with a first episode of psychosis may be the result of methodological bias introduced by unequal dosing between the two drugs or the use of chronically ill and treatment-refractory patients in previous studies.

Pharmacological characterization of AC-90179 [2-(4-methoxyphenyl)-N-(4-methyl-benzyl)-N-(1-methyl-piperidin-4-yl)-acetamide hydrochloride]: a selective serotonin 2A receptor inverse agonist

The primary purpose of the present series of experiments was to characterize the in vitro and in vivo pharmacology profile of 2-(4-methoxy-phenyl)-N-(4-methyl-benzyl)-N-(1-methyl-piperidin-4-yl)-acetamide hydrochloride (AC-90179), a selective serotonin (5-HT2A) receptor inverse agonist, in comparison with the antipsychotics haloperidol and clozapine. The secondary purpose was to characterize the pharmacokinetic profile of AC-90179. Like all atypical antipsychotics, AC-90179 shows high potency as an inverse agonist and competitive antagonist at 5HT2A receptors. In addition, AC-90179 exhibits antagonism at 5HT2C receptors. In contrast, AC-90179 does not have significant potency for D2 and H1 receptors that have been implicated in the dose-limiting side effects of other antipsychotic drugs. The ability of AC-90179 to block 5-HT2A receptor signaling in vivo was demonstrated by its blockade of the rate-decreasing effects of the 5-HT2A agonist, (+/-)-2,5-dimethoxy-4-iodoamphetamine hydrochloride, under a fixed ratio schedule of reinforcement. Similar to clozapine and haloperidol, AC-90179 attenuated phencyclidine-induced hyperactivity. Although haloperidol impaired acquisition of a simple autoshaped response and induced cataleptic-like effects at behaviorally efficacious doses, AC-90179 and clozapine did not. Furthermore, unlike haloperidol and clozapine, AC-90179 did not decrease spontaneous locomotor behavior at efficacious doses. Limited oral bioavailability of AC-90179 likely reflects rapid metabolism rather than poor absorption. Taken together, a compound with a similar pharmacological profile as AC-90179 and with increased oral bioavailability may have potential for the treatment of psychosis.

Risperidone in acute and long-term therapy of schizophrenia--a clinical profile

Data from a range of well-controlled clinical trials, observational studies, and clinical use support the efficacy of risperidone for both acute and long-term therapy of schizophrenic psychoses. With regard to positive symptoms, the efficacy of risperidone was shown to be at least comparable with that of haloperidol. However, risperidone differs from conventional antipsychotics because it is more effective against the negative symptoms, has beneficial effects on affective and cognitive symptoms, and carries less risk of extrapyramidal side effects (EPS). To date, risperidone is the only atypical antipsychotic to have shown a significantly lower relapse rate compared with haloperidol in a long-term double-blind trial. This review describes comprehensive trial data and therapeutic observations gained with risperidone in the treatment of schizophrenia since its approval.

Impact on cognition of the use of antipsychotics

Cognitive dysfunction is recognised as one of the more enduring deficits in schizophrenia. The syndrome is associated with impairment of the temporal and frontal regions of the brain that are concerned with cognitve function, as well as subcortical regions that are closely interconnected with them. Cognitive dysfunction may underpin some of the psychopathology of schizophrenia, as well as contribute to the patient's impaired social and vocational functioning. Cognitive deficits are relatively independent of psychotic symptoms in schizophrenia, and are probably central and enduring features of the disorder. It must also be considered that cognitive disability may be rate-limiting to the schizophrenic patient's rehabilitation and impairs quality of life. Although there is a general consensus that neuroleptic drugs are able to improve the psychopathology of schizophrenia, there is continued debate concerning their impact on cognitve function. Chronic treatment with classical neuroleptics has been reported to produce only minimal improvement in, and may actually impair, cognitive function in schizophrenia. In contrast, novel antipsychotics seem to cause less cognitive impairment than classical antipsychotic medication and may improve cognitive function. Whilst in the past research focused on the development of clinically effective antipsychotic drugs with a reduced propensity to cause extrapyramidal symptoms (EPS), it is now being recognised that maintaining and enhancing cognitive function and improving quality of life should be the goal in the treatment of schizophrenia.

Treatment-refractory schizophrenia

Treatment-refractory schizophrenia is common. Refinements in pharmacologic and psychosocial treatments of schizophrenia offer the expectation of superior outcomes for this disadvantaged patient group. This article critically reviews those articles that were published during the year 2000 that address this treatment-refractory population.