Open, randomized trial of the effects of aripiprazole versus risperidone on social cognition in schizophrenia

Aripiprazole 2-month ready-to-use 960 mg (Ari 2MRTU): review of its possible role in schizophrenia therapy

Most patients with schizophrenia need life-long treatment. There is therefore a continued need for effective and tolerable treatment options. A 2-monthly LAI formulation of aripiprazole, Aripiprazole 2-Month Ready-to-Use 960 mg (Ari 2MRTU 960) has recently been approved in the US. Here, the possible role in therapy for this new treatment option is discussed in a narrative review. PubMed was searched for literature on long-acting injectables with a focus on patient-reported outcomes and real-world evidence on extended injection intervals (2-3 months). Dopamine D2 partial agonists, one of which is aripiprazole, exhibit favorable tolerability and safety properties. Additionally, there are many advantages in using long-acting injectable formulations such as enhanced treatment persistence and stability of patients as well as reduced rates of relapses, hospitalizations, and death. Some of these advantages become more pronounced with longer injection intervals. Additional advantages of longer injection intervals are more room for non-medication-related communication between healthcare professionals and patients, patient and physician preferences, reduced caregiver burden, and easier transitioning from inpatient to outpatient treatment. Taken together, since aripiprazole may be a good treatment choice for many patients based on its favorable safety and tolerability profile, and given the advantages of LAI treatment over oral treatment and the advantages of reduced dosing frequency, Ari 2MRTU 960 may become an important treatment option for many clinically stable patients with schizophrenia.

Aripiprazole Attenuates Cognitive Impairments Induced by Lipopolysaccharide in Rats through the Regulation of Neuronal Inflammation, Oxidative Stress, and Apoptosis

Background and Objectives: Aripiprazole (APZ), an atypical antipsychotic, is mainly prescribed for conditions such as schizophrenia and bipolar disorder, while ongoing research indicates promising neuroprotective qualities. APZ's mechanism of action, involving the regulation of neurotransmitter levels, appears to contribute to its potential to shield neural tissues from specific forms of harm and degeneration. Materials and Methods: To investigate its neuroprotective mechanisms, groups of rats were orally administered APZ at 1 or 2 mg/kg once daily for a 30-day period. In addition, neuronal toxicity was induced through intraperitoneal injection of four doses of lipopolysaccharide (LPS) at a concentration of 1 mg/kg. To evaluate cognitive function, particularly, short-term recognition memory, the procedure implemented the novel object recognition (NOR) task. Subsequently, brain tissues were gathered to examine markers linked with neuroinflammation, oxidative stress, and apoptosis. Results: The administration of LPS led to a decline in memory performance during the NOR tasks. Simultaneously, this LPS treatment raised inflammatory markers like cyclooxygenase (COX)-2, tumor necrosis factor (TNF)-α, and nuclear factor kappa B (NF-κB), increased oxidative markers such as malondialdehyde (MDA), and triggered apoptosis markers like Caspase-3 and Bcl2 associated X protein (Bax) within the brain. Furthermore, it decreased levels of antioxidants like reduced glutathione (GSH) and catalase, as well as the anti-apoptotic marker B-cell lymphoma (Bcl)-2 in brain tissue. The use of APZ resulted in enhanced recognition memory performance, as indicated by improved exploration and discrimination abilities of the objects in the NOR task. Moreover, APZ lowered the markers associated with neuronal vulnerability, such as COX-2, NF-κB, MDA, Caspase-3, and Bax. Additionally, it increased the levels of protective markers, including GSH, catalase, and Bcl-2 in LPS-challenged brains. Conclusions: In summary, the findings suggest that APZ exhibits protective properties against neuronal inflammation, oxidative stress, and apoptosis markers in the context of inflammatory-related neurodegeneration. Additional in-depth investigations are needed to further explore potential applications.

Place of the partial dopamine receptor agonist aripiprazole in the management of schizophrenia in adults: a Delphi consensus study

BACKGROUND

Aripiprazole is a second-generation antipsychotic, efficacious in patients with schizophrenia during acute episodes. Due to its pharmacological profile, aripiprazole may be of interest in patients with specific clinical profiles who have not been studied extensively in randomised clinical trials.

OBJECTIVES

To capture experience with aripiprazole in everyday psychiatric practice using the Delphi method in order to inform decision-making on the use of aripiprazole for the treatment of patients with schizophrenia in clinical situations where robust evidence from clinical trials is lacking.

METHODS

The scope of the survey was defined as the management of schizophrenia in adults. A systematic literature review was performed to identify the different clinical situations in which aripiprazole has been studied, and to describe the level of clinical evidence. Clinical profiles to include in the Delphi survey were selected if there was a clear interest in terms of medical need but uncertainty over the efficacy of aripiprazole. For each clinical profile retained, five to seven specific statements were generated and included in a questionnaire. The final 41-item questionnaire was proposed to a panel of 406 French psychiatrists with experience in the treatment of schizophrenia. Panellists rated their level of agreement using a Likert scale. A second round of voting on eleven items was organised to clarify points for which a consensus was not obtained in the first round.

RESULTS

Five clinical profiles were identified in the literature review (persistent negative symptoms, pregnancy, cognitive dysfunction, addictive comorbidity and clozapine resistance). Sixty-two psychiatrists participated in the first round of the Delphi survey and 33 in the second round. A consensus was obtained for 11 out of 41 items in the first round and for 9/11 items in the second round. According to the panellists' clinical experience, aripiprazole can be used as maintenance treatment for pregnant women, is relevant to preserve cognitive function and can be considered an option in patients with a comorbid addictive disorder or with persistent negative symptoms.

CONCLUSION

These findings may help physicians in choosing relevant ways to use aripiprazole and highlight areas where more research is needed to widen the evidence base.

A systematic review of the effects of psychiatric medications on social cognition

INTRODUCTION

Social cognition is an important area of mental functioning relevant to psychiatric disorders and social functioning, that may be affected by psychiatric drug treatments. The aim of this review was to investigate the effects of medications with sedative properties, on social cognition.

METHOD

This systematic review included experimental and neuroimaging studies investigating drug effects on social cognition. Data quality was assessed using a modified Downs and Black checklist (Trac et al. CMAJ 188: E120-E129, 2016). The review used narrative synthesis to analyse the data.

RESULTS

40 papers were identified for inclusion, 11 papers investigating benzodiazepine effects, and 29 investigating antipsychotic effects, on social cognition. Narrative synthesis showed that diazepam impairs healthy volunteer's emotion recognition, with supporting neuroimaging studies showing benzodiazepines attenuate amygdala activity. Studies of antipsychotic effects on social cognition gave variable results. However, many of these studies were in patients already taking medication, and potential practice effects were identified due to short-term follow-ups.

CONCLUSION

Healthy volunteer studies suggest that diazepam reduces emotional processing ability. The effects of benzodiazepines on other aspects of social cognition, as well as the effects of antipsychotics, remain unclear. Interpretations of the papers in this review were limited by variability in measures, small sample sizes, and lack of randomisation. More robust studies are necessary to evaluate the impact of these medications on social cognition.

Different neurocognitive profiles of risperidone and aripiprazole in the FIRST episode of psychosis: A 3-year follow-up comparison

Cognitive deficits have been recognized as a central feature of schizophrenia spectrum disorders. These deficits are often related to more severe negative symptoms, as well as a poorer adjustment in social functioning. Therefore, it is important to improve cognitive performance from the onset of the disease. In this study, we compared the effects of two atypical antipsychotics, risperidone and aripiprazole, on cognition. The data used in the present investigation were obtained from a large epidemiological cohort of patients with a first episode of psychosis who were treated in a longitudinal intervention programme. The patients included in the program were randomized to treatment with risperidone or aripiprazole and were assessed for cognitive function at baseline and 3 years later. The final sample consisted of 115 patients, 55 of whom were initially assigned to risperidone and 60 to aripiprazole. The groups did not show significant differences in their sociodemographic or clinical characteristics at intake. Longitudinal analyses showed that risperidone-treated patients improved in the processing speed domain at the 3-year follow-up, while the aripiprazole group showed better scores for the executive function domain. Our study shows slight differences between the effects of risperidone and aripiprazole on cognition, suggesting different patterns of efficacy on cognitive function that may warrant more thorough research to determine the beneficial effects of these drugs on cognition. Future studies should evaluate the effects of these treatments over longer follow-up periods using standardized tools for the assessment of cognitive function.

Pharmacological Treatment for Social Cognition: Current Evidence

Cognitive impairment is currently considered a core feature of schizophrenia (SZ) and is gaining attention as a fundamental therapeutic target. Standard treatment for SZ involves the use of antipsychotics that are successfully used to control positive symptoms and disorganized behaviour. However, it is still unclear whether they are effective on social cognition (SC) impairment. Furthermore, different medications are currently being studied to improve SC in patients with SZ. A literature search on this topic was conducted using the PubMed database. All kinds of publications (i.e., reviews, original contributions and case reports) written in English and published in the last 15 years were included. The aim of our literature review is to draw a picture of the current state of the pharmacological treatment of SC impairment in SZ.

Long acting aripiprazole influences cognitive functions in recent onset schizophrenia

RATIONALE

Beneficial effects of aripiprazole on cognition in schizophrenia have been previously reported, but not in recent onset schizophrenia. Cognitive impairments have also been associated with catechol-O-methyltransferase (COMT), methylenetetrahydrofolate reductase (MTHFR), and serotonin transporter (SERT) gene polymorphisms which were earlier implicated in the pathophysiology of schizophrenia.

OBJECTIVES

This study examined the short-term influence of aripiprazole long-acting injectable (LAI) as well as of COMT, MTHFR, and SERT gene polymorphisms and their interactions on clinical features and cognitive functions in inpatients with recent onset schizophrenia.

METHODS

This study included 98 inpatients suffering from recent onset schizophrenia diagnosed according to DSM-5 criteria. Three months after initiating aripiprazole LAI, the severity of symptoms was assessed by the Positive and Negative Syndrome Scale (PANSS), while cognitive functions were measured by 5-KOG test for cognition. Genotypes of SERT, MTHFR, and COMT gene were determined by different polymerase chain reaction (PCR) methods.

RESULTS

Three-month aripiprazole LAI treatment was associated with a statistically significant change of PANSS total (p<0.001) and subscale scores as well as cognitive parameters of delayed recall (p<0.03), attention (p<0.01), and executive functions in the form of less perseverations (p<0.03), without influencing other examined cognitive functions. However, it significantly influenced composite cognitive score (p<0.02). In regard to the investigated genetic polymorphisms, we established a positive association between the COMT polymorphism (M/M allele carriers) and attention (p<0.01). Additionally, we also established a positive association between the COMT - MTHFR interaction and attention (p<0.02), as well as perseveration item belonging to executive functions (p<0.01). Two other investigated polymorphisms (MTHFR and SERT) were not significantly associated with cognitive indices. Investigated genetic polymorphisms and their interactions were not associated with PANSS scores.

CONCLUSIONS

Our findings suggest that aripiprazole LAI improves individual cognitive functions in recent onset schizophrenia. Investigated COMT polymorphism (Met/Met genotype), as well as the COMT-MTHFR interaction, were positively associated with attention and executive functioning (perseveration), potentially implying COMT's biomarker potential in terms of cognition in schizophrenia.

Efficacy and tolerability of aripiprazole versus D2 antagonists in the early course of schizophrenia: a systematic review and meta-analysis

Early intervention is essential for favorable long-term outcomes in schizophrenia. However, there is limited guidance in the scientific literature on how best to choose between dopamine D₂ receptor (D₂R) partial agonists and D₂R antagonists in early stages of schizophrenia. The aim of this meta-analysis was to directly compare D₂R partial agonists with D₂R antagonists for efficacy and tolerability, using randomized controlled trials (RCTs) that involved participants diagnosed with first-episode psychosis, schizophrenia, or related psychotic disorders with a duration of illness ≤5 years. Fourteen RCTs, involving 2494 patients, were included in the meta-analysis. Aripiprazole was the only identified D₂R partial agonist, and was not significantly different from pooled D₂R antagonists for overall symptom reduction or all-cause discontinuation. However, aripiprazole was more favorable than pooled D₂R antagonists for depressive symptoms, prolactin levels, and triglyceride levels. Specifically, aripiprazole was more favorable than paliperidone for triglyceride levels and more favorable than risperidone and olanzapine, but less favorable than ziprasidone, for weight gain. In addition, aripiprazole was less favorable for akathisia compared with second-generation D₂R antagonists, in particular olanzapine and quetiapine, and less favorable for discontinuation due to inefficacy than risperidone. Lastly, aripiprazole was more favorable than haloperidol for various efficacy and tolerability outcomes. In conclusion, aripiprazole’s efficacy did not differ substantially from D₂R antagonists in the early course of schizophrenia, whereas differential tolerability profiles were noted. More double-blind RCTs are required comparing the efficacy and tolerability of aripiprazole as well as other D₂R partial agonists with D₂R antagonists in early stages of schizophrenia.

Cognitive Outcomes with Sequential Escitalopram Monotherapy and Adjunctive Aripiprazole Treatment in Major Depressive Disorder: A Canadian Biomarker Integration Network in Depression (CAN-BIND-1) Report

BACKGROUND

Cognitive deficits are detectable in major depressive disorder (MDD). The cognitive impact of antidepressants remains unclear, as does the cognitive effects of aripiprazole in MDD, a commonly used adjunct with putative pro-cognitive properties.

OBJECTIVES

In this multi-centre, open-label study, cognitive changes associated with escitalopram monotherapy and adjunctive aripiprazole were examined.

METHODS

Acutely depressed participants with MDD (n = 209) received 8 weeks of escitalopram. Non-responders received an additional 8 weeks of adjunctive aripiprazole (ESC-ARI, n = 88), while responders (ESC-CONT, n = 82) continued escitalopram monotherapy (n = 39 lost to attrition). ESC-ARI, ESC-CONT and matched healthy participants (n = 112) completed the Central Nervous System Vital Signs cognitive battery at baseline, 8 and 16 weeks. Linear mixed models compared participants with MDD cognitive trajectories with healthy participants.

RESULTS

Participants with MDD displayed poorer baseline global cognition (assessed via the Neurocognitive Index), composite memory and psychomotor speed vs healthy participants. There were no statistically significant changes in participants with MDD receiving escitalopram monotherapy from baseline to week 8 in the neurocognitive index, reaction time, complex attention, cognitive flexibility, memory or psychomotor speed. Overall symptom severity changes were not associated with cognitive changes. The ESC-CONT group displayed no significant cognitive changes from weeks 8 to 16; reaction time worsened in the ESC-ARI group (p = 0.008) from weeks 8 to 16, independent of symptom change.

CONCLUSIONS

Escitalopram monotherapy in acute MDD did not result in significant cognitive improvements. We provide novel evidence that escitalopram continuation in responders does not adversely affect cognition, but adjunctive aripiprazole in escitalopram non-responders worsens reaction time. Treatments targeting cognitive dysfunction are needed in MDD. CLINICALTRIALS.

GOV IDENTIFIER

NCT01655706; 2 August, 2012.

Updating the Comparative Evidence on Second‐Generation Antipsychotic Use With Schizophrenia

Objective

The objective of this study was to conduct a systematic review of literature comparing second‐generation antipsychotics (SGAs) with each other and with first‐generation antipsychotics (FGAs) in treating schizophrenia.

Methods

MEDLINE, the Cochrane Library, and PsycINFO databases were searched through January 2020. Following standard methods, recent high‐quality systematic reviews of each drug comparison and subsequently published primary studies were included to update the meta‐analyses with any new data. Two reviewers independently conducted study selection, abstraction, and quality assessment.

Results

Two systematic reviews and 29 newer trials (total of 162 trials of SGAs, N=53,861; 116 trials of SGAs versus FGAs, N=119,558) were included. Most trials were of fair quality, industry‐funded, and included older SGAs and a few recently approved SGAs (asenapine, lurasidone, iloperidone, cariprazine, brexpiprazole and long‐acting injection [LAI] formulations of aripiprazole and paliperidone). Older SGAs had similar effects on function, quality of life, mortality, and adverse event incidence, although clozapine improved symptoms more than most other drugs and olanzapine and risperidone were superior to some other drugs. Olanzapine, risperidone, ziprasidone, and aripiprazole performed similarly on outcomes of benefit compared with haloperidol. Risperidone LAI and olanzapine resulted in fewer withdrawals due to adverse events, but risk of diabetes increased with olanzapine. Haloperidol had greater incidence of adverse events than did olanzapine and risperidone, but similar effects on other outcomes.

Conclusions

Most comparative evidence favored older SGAs, with clozapine, olanzapine, and risperidone superior on more outcomes than other SGAs. Older SGAs had similar benefits as haloperidol but with fewer adverse events.

Use of the second‐generation antipsychotics olanzapine, aripiprazole, risperidone, quetiapine, and ziprasidone resulted in similar function, quality of life, mortality, and overall incidence of adverse events.

Core illness symptoms improved more with olanzapine and risperidone than asenapine, quetiapine, or ziprasidone, and more with paliperidone than lurasidone or iloperidone.

Haloperidol showed similar benefits but more adverse events than did olanzapine or risperidone.

The Schizophrenia Susceptibility Gene OPCML Regulates Spine Maturation and Cognitive Behaviors through Eph-Cofilin Signaling

Previous genetic and biological evidence converge on the involvement of synaptic dysfunction in schizophrenia, and OPCML, encoding a synaptic membrane protein, is reported to be genetically associated with schizophrenia. However, its role in the pathophysiology of schizophrenia remains largely unknown. Here, we found that Opcml is strongly expressed in the mouse hippocampus; ablation of Opcml leads to reduced phosphorylated cofilin and dysregulated F-actin dynamics, which disturbs the spine maturation. Furthermore, Opcml interacts with EphB2 to control the stability of spines by regulating the ephrin-EphB2-cofilin signaling pathway. Opcml-deficient mice display impaired cognitive behaviors and abnormal sensorimotor gating, which are similar to features in neuropsychiatric disorders such as schizophrenia. Notably, the administration of aripiprazole partially restores the abnormal behaviors in Opcml^-/- mice by increasing the phosphorylated cofilin level and facilitating spine maturation. We demonstrated a critical role of the schizophrenia-susceptible gene OPCML in spine maturation and cognitive behaviors via regulating the ephrin-EphB2-cofilin signaling pathway, providing further insights into the characteristics of schizophrenia.

An open-label randomised comparison of aripiprazole, olanzapine and risperidone for the acute treatment of first-episode schizophrenia: Eight-week outcomes

PURPOSE

This study aimed to investigate the efficacy and tolerability of aripiprazole, olanzapine and risperidone in first-episode schizophrenia (FES).

METHODS

The eight-week, open, randomised study was conducted in six Chinese medical centres. Altogether, 498 FES subjects were randomised to aripiprazole (n = 165), olanzapine (n = 168) or risperidone (n = 165). Efficacy was measured with the Positive and Negative Syndrome Scale (PANSS), tolerability with the Udvalg for Kliniske Undersogelser Side Effect Rating Scale (UKU) and functioning with the Personal and Social Performance Scale (PSP).

RESULTS

All three antipsychotics significantly improved the baseline to end-point PANSS total and each of the sub-scale scores (p < 0.001). Risperidone was superior to olanzapine and aripiprazole regarding PANSS total end-point scores (p < 0.05). Cumulative response (PANSS total score reduction ⩾30%) was similar between risperidone, olanzapine and aripiprazole (74.8%, 73.5% and 70.1%; p = 0.707), but risperidone was superior to aripiprazole regarding PANSS total score reduction ⩾50% (37.8% vs. 26.6%; p < 0.05). Olanzapine was associated with the largest weight gain at week 4 and 8 (p < 0.01), weight gain ⩾7% (olanzapine = 49.0% vs. risperidone = 32.5% vs. aripiprazole = 17.0%; p < 0.01), more psychic side effects at week 8 (p < 0.01 each) and more 'other' side effects at week 4 (p < 0.001) and week 8 (p < 0.05) but fewer neurological side effects at week 4 (p < 0.05) and week 8 (p < 0.01). PSP improved more with risperidone than with aripiprazole at week 4 and 8 (p < 0.05).

CONCLUSIONS

For FES, risperidone might be a better choice than aripiprazole due to improved efficacy and functional improvement, without inferior tolerability. Aripiprazole is a better choice to avoid relevant short-term weight gain. Olanzapine could be chosen to avoid neurological adverse effects.

Interventions and social functioning in youth at risk of psychosis: A systematic review and meta-analysis

AIM

Youth at clinical high risk (CHR) for psychosis often exhibit difficulties in social functioning and poorer social functioning may be predictive of transition to a psychotic disorder. Therefore, the primary objective of this systematic review was to summarize the impact of all interventions on social functioning in CHR samples.

METHOD

Electronic databases PsycINFO, CINAHL, Embase, EBM, and MEDLINE were searched from 1951 to June 2017. Studies were selected if they included any intervention that reported changes in social functioning in youth at CHR. Data were evaluated using random effects pairwise meta-analyses, stratified by time, and reported as the standardized mean difference (SMD).

RESULTS

Nineteen studies met our inclusion criteria, including a total of 1513 CHR participants. The mean age was 20.5 years and 47% were male. Cognitive behavioural therapy (4 studies) did not significantly improve social functioning at 6 months (SMD = 0.06; 95% confidence interval [CI] = -0.35, 0.46), 12 months (SMD = -0.15; 95% CI = -0.38, 0.08) and 18 months (SMD = 0.20; 95% CI = -0.10, 0.50). Omega-3 (2 studies) did not significantly improve social functioning at 6 months (SMD = 0.01; 95% CI = -0.21, 0.24) and 12 months (SMD = -0.08; 95% CI = -0.33, 0.17). Lastly, cognitive remediation (3 studies) did not significantly improve social functioning at 2- to 3-month follow-up (SMD = 0.13, 95% CI = -0.18, 0.43).

CONCLUSIONS

This systematic review and meta-analysis demonstrated that no treatment significantly improved social functioning in youth at CHR. Future randomized control trials are required that are designed to target and improve social functioning in youth at CHR for psychosis.

The Importance of Social Cognition in Improving Functional Outcomes in Schizophrenia

Social cognition has become recognized as an important driver of functional outcomes and overall recovery in patients with schizophrenia, mediating the relationship between neurocognition and social functioning. Since antipsychotic therapy targeting remission of clinical symptoms has been shown to have a limited impact on social cognition, there has been an increasing drive to develop therapeutic strategies to specifically improve social cognition in schizophrenia. We sought to review current evidence relating to social cognition in schizophrenia and its clinical implications, including interventions designed to target the core domains of social cognition (emotion processing, theory of mind, attributional bias, and social perception) as a means of improving functional outcomes and thereby increasing the likelihood of recovery. Relevant articles were identified by conducting a literature search in PubMed using the search terms "schizophrenia" AND "cognition" AND "social functioning," limited to Title/Abstract, over a time period of the past 10 years. Current evidence demonstrates that schizophrenia is associated with impairments in all four core domains of social cognition, during the pre-first-episode, first-episode, early, and chronic phases of the disease, and that such impairments are important determinants of functional outcome. Interventions targeting the four core domains of social cognition comprise psychosocial approaches (social cognition training programs) and pharmacological therapies. Social cognition training programs targeting multiple and specific core domains of social cognition have shown promise in improving social cognition skills, which, in some cases, has translated into improvements in functional outcomes. Use of some psychosocial interventions has additionally resulted in improvements in clinical symptoms and/or quality of life. Pharmacological therapies, including oxytocin and certain antipsychotics, have yielded more mixed results, due in part to the confounding impact of factors including variation in receptor genetics, bioavailability, pharmacokinetics, and drug-drug interactions, and inconsistencies between study designs and medication dosages. Additional research is required to advance our understanding of the role of social cognition in schizophrenia, and to further establish the utility of targeted interventions in this setting.

Late Reduction of Cocaine Cravings in a Randomized, Double-Blind Trial of Aripiprazole vs Perphenazine in Schizophrenia and Comorbid Cocaine Dependence

PURPOSE

Co-occurring schizophrenia spectrum disorder and International Statistical Classification of Diseases, 10th Revision cocaine dependence present a particularly destructive constellation that is often difficult to treat. Both conditions raise dopamine transmission effects in the brain. Traditional neuroleptics block dopamine receptors, whereas aripiprazole modulates dopamine activity as an agonist/antagonist. We tested whether dopamine modulation is superior to dopamine blocking in dual-diagnosis patients.

METHODS

In a randomized, double-blind, comparison design, cocaine-dependent schizophrenic subjects actively using cocaine received either aripiprazole or perphenazine in an 8-week trial. Primary outcome targeted cocaine-free urine sample proportions, whereas cocaine craving scores were a secondary variable.

RESULTS

Subjects (N = 44) randomized (n = 22 per group) did not differ at baseline. The proportion of cocaine-free urine samples did not differ by medication group. Contrasting weeks 3 to 5 vs 6 to 8 revealed significant late reductions in craving with aripiprazole. On the respective 5-point subscales, craving intensity decreased by 1.53 ± 0.43 (P < 0.0005) points, craving frequency by 1.4 ± 0.40 (P > 0.0004) points, and craving duration by 1.76 ± 0.44 (P > 0.0001) points.

CONCLUSIONS

A drug effect of aripiprazole on craving items appeared at week 6 of treatment, on average, and was not seen before that length of drug exposure. The data suggest that dopamine modulation reduces cocaine cravings but requires an acclimation period. To understand the mechanism of action better, a trial of depot aripiprazole may be useful. Clinically, a reduction in craving potentially offers a clearer focus for ongoing behavioral treatment. It may also offer a longer-term treatment effect with respect to the severity of relapse.

Specific effect of a dopamine partial agonist on counterfactual learning: evidence from Gilles de la Tourette syndrome

The dopamine partial agonist aripiprazole is increasingly used to treat pathologies for which other antipsychotics are indicated because it displays fewer side effects, such as sedation and depression-like symptoms, than other dopamine receptor antagonists. Previously, we showed that aripiprazole may protect motivational function by preserving reinforcement-related signals used to sustain reward-maximization. However, the effect of aripiprazole on more cognitive facets of human reinforcement learning, such as learning from the forgone outcomes of alternative courses of action (i.e., counterfactual learning), is unknown. To test the influence of aripiprazole on counterfactual learning, we administered a reinforcement learning task that involves both direct learning from obtained outcomes and indirect learning from forgone outcomes to two groups of Gilles de la Tourette (GTS) patients, one consisting of patients who were completely unmedicated and the other consisting of patients who were receiving aripiprazole monotherapy, and to healthy subjects. We found that whereas learning performance improved in the presence of counterfactual feedback in both healthy controls and unmedicated GTS patients, this was not the case in aripiprazole-medicated GTS patients. Our results suggest that whereas aripiprazole preserves direct learning of action-outcome associations, it may impair more complex inferential processes, such as counterfactual learning from forgone outcomes, in GTS patients treated with this medication.

Risperidone improves interpersonal perception and executive function in patients with schizophrenia

OBJECTIVE

To investigate whether risperidone improves social cognitive impairments and executive dysfunction in people with schizophrenia.

METHODS

Fifty-six patients who met the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, diagnostic criteria for schizophrenia were allocated to a risperidone treatment group (RTG, n=28) and a typical antipsychotic treatment group (TATG, n=28). Twenty-eight healthy volunteers were recruited as the normal control group (NCG). The Positive and Negative Syndrome Scale, Interpersonal Perception Task-15 (IPT-15), and Wisconsin Card Sorting Test (WCST) were rated at baseline and after 4 and 12 weeks of treatment with risperidone or typical antipsychotics.

RESULTS

Risperidone and typical antipsychotics decreased Positive and Negative Syndrome Scale scores for total psychopathology and positive and negative symptoms. At baseline, in the IPT-15, total scores and five factor scores, as well as the number of categories completed and the percentage of conceptual level responses, were significantly lower in the RTG and TATG than in the NCG, whereas total response errors, perseverative errors, and failure to maintain set were significantly higher in the patient groups than in the NCG. Repeated measures analysis of variance revealed a significant main effect of time period (baseline, 4 weeks, and 12 weeks) for IPT-15 scores and WCST performances, and significant interactions for time period × group (RTG and TATG). Multivariate analysis of variance showed no significant differences between the RTG and TATG on IPT-15 scores at 4 weeks, but there were significant differences between these two groups at 12 weeks. Significant differences were also found between the RTG and TATG on WCST performances at 4 and 12 weeks.

CONCLUSION

Individuals with schizophrenia have impairments in social cognitive and executive function, which might be improved by risperidone.

Serum brain-derived neurotrophic factor levels associate with cognitive improvement in patients with schizophrenia treated with electroacupuncture

Accumulating evidence supports that acupuncture has been successfully used for the treatment of neurological disorders to improve cognitive function. This study was set to evaluate the efficacy of electroacupuncture (EA, using two acupoints: Baihui and Shenting) on clinical symptoms, cognitive function and brain-derived neurotrophic factor (BDNF) levels in patients with schizophrenia. Sixty-one inpatients diagnosed schizophrenia with DSM-IV criteria were recruited. The participants were randomly divided into an experimental group (n=30) and a control group (n=31). The patients were evaluated using the Positive and Negative Symptom Scale (PANSS), the Wisconsin Card Sorting Test (WCST) and Wechsler Memory Scale (WMS) at baseline and after EA treatment. There were no significant differences in the PANSS scores and serum BDNF levels between the experimental group and the control group, either at baseline or at the end of the 4-week study period. However, the EA treatment appeared to have significant benefits on memory and moderate benefits on executive functions and problem solving. Significant positive correlation was observed between the increase of BDNF levels and memory improvement after EA treatment. Our results indicated that EA treatment could improve cognitive function, and the cognitive benefits positively associate with serum BDNF levels in patients with schizophrenia.

MK-801-induced deficits in social recognition in rats: reversal by aripiprazole, but not olanzapine, risperidone, or cannabidiol

Deficiencies in social activities are hallmarks of numerous brain disorders. With respect to schizophrenia, social withdrawal belongs to the category of negative symptoms and is associated with deficits in the cognitive domain. Here, we used the N-methyl-D-aspartate receptor antagonist dizocilpine (MK-801) for induction of social withdrawal in rats and assessed the efficacy of several atypical antipsychotics with different pharmacological profiles as putative treatment. In addition, we reasoned that the marijuana constituent cannabidiol (CBD) may provide benefit or could be proposed as an adjunct treatment in combination with antipsychotics. Hooded Lister rats were tested in the three-chamber version for social interaction, with an initial novelty phase, followed after 3 min by a short-term recognition memory phase. No drug treatment affected sociability. However, distinct effects on social recognition were revealed. MK-801 reduced social recognition memory at all doses (>0.03 mg/kg). Predosing with aripiprazole dose-dependently (2 or 10 mg/kg) prevented the memory decline, but doses of 0.1 mg/kg risperidone or 1 mg/kg olanzapine did not. Intriguingly, CBD impaired social recognition memory (12 and 30 mg/kg) but did not rescue the MK-801-induced deficits. When CBD was combined with protective doses of aripiprazole (CBD-aripiprazole at 12 :  or 5 : 2 mg/kg) the benefit of the antipsychotic was lost. At the same time, activity-related changes in behaviour were excluded as underlying reasons for these pharmacological effects. Collectively, the combined activity of aripiprazole on dopamine D2 and serotonin 5HT1A receptors appears to provide a significant advantage over risperidone and olanzapine with respect to the rescue of cognitive deficits reminiscent of schizophrenia. The differential pharmacological properties of CBD, which are seemingly beneficial in human patients, did not back-translate and rescue the MK-801-induced social memory deficit.

Relative to Typical Antipsychotic Drugs, Aripiprazole Is a Safer Alternative for Alleviating Behavioral Disturbances After Experimental Brain Trauma

BACKGROUND

Antipsychotic drugs (APDs) are used to manage traumatic brain injury (TBI)-induced behavioral disturbances, such as agitation and aggression. However, APDs exhibiting D₂ receptor antagonism impede cognitive recovery after experimental TBI. Hence, empirical evaluation of APDs with different mechanistic actions is warranted. Aripiprazole (ARIP) is a D₂ and 5-hydroxytryptamine_1A (5-HT_1A) receptor agonist; pharmacotherapies with these properties enhance cognition after TBI.

OBJECTIVE

To test the hypothesis that ARIP would increase behavioral performance and decrease histopathology after TBI.

METHODS

Adult male rats were subjected to either a controlled cortical impact (CCI) or sham injury and then randomly assigned to ARIP (0.1 or 1.0 mg/kg) or VEH (1.0 mL/kg, saline vehicle) groups. Treatments began 24 hours after surgery and were administered once daily for 19 days. Motor (beam-balance/beam-walk) and cognitive (Morris water maze) performance was assessed on postoperative days 1 to 5 and 14 to 19, respectively, followed by quantification of hippocampal CA_1,3 neuron survival and cortical lesion volume.

RESULTS

Beam-balance was significantly improved in the CCI + ARIP (1.0 mg/kg) group versus CCI + ARIP (0.1 mg/kg) and CCI + VEH (P < .05). Spatial learning and memory retention were significantly improved in the CCI + ARIP (0.1 mg/kg) group versus the CCI + ARIP (1.0 mg/kg) and CCI + VEH groups (P < .05). Both doses of ARIP reduced lesion size and CA₃ cell loss versus VEH (P < .05). Importantly, neither dose of ARIP impeded functional recovery as previously reported with other APDs.

CONCLUSION

These findings support the hypothesis and endorse ARIP as a safer APD for alleviating behavioral disturbances after TBI.

An investigation into aripiprazole's partial D₂ agonist effects within the dorsolateral prefrontal cortex during working memory in healthy volunteers

RATIONALE

Working memory impairments in schizophrenia have been attributed to dysfunction of the dorsolateral prefrontal cortex (DLPFC) which in turn may be due to low DLPFC dopamine innervation. Conventional antipsychotic drugs block DLPFC D2 receptors, and this may lead to further dysfunction and working memory impairments. Aripiprazole is a D2 receptor partial agonist hypothesised to enhance PFC dopamine functioning, possibly improving working memory.

OBJECTIVES

We probed the implications of the partial D2 receptor agonist actions of aripiprazole within the DLPFC during working memory. Investigations were carried out in healthy volunteers to eliminate confounds of illness or medication status. Aripiprazole's prefrontal actions were compared with the D2/5-HT2A blocker risperidone to separate aripiprazole's unique prefrontal D2 agonist actions from its serotinergic and striatal D2 actions that it shares with risperidone.

METHOD

A double-blind, placebo-controlled, parallel design was implemented. Participants received a single dose of either 5 mg aripiprazole, 1 mg risperidone or placebo before performing the n-back task whilst undergoing fMRI scanning.

RESULTS

Compared with placebo, the aripiprazole group demonstrated enhanced DLPFC activation associated with a trend for improved discriminability (d') and speeded reaction times. In contrast to aripiprazole's neural effects, the risperidone group demonstrated a trend for reduced DLPFC recruitment. Unexpectedly, the risperidone group demonstrated similar effects to aripiprazole on d' and additionally had reduced errors of commission compared with placebo.

CONCLUSION

Aripiprazole has unique DLPFC actions attributed to its prefrontal D2 agonist action. Risperidone's serotinergic action that results in prefrontal dopamine release may have protected against any impairing effects of its prefrontal D2 blockade.

Improvement in social and cognitive functioning associated with paliperidone extended-release treatment in patients with schizophrenia: a 24-week, single arm, open-label study

PURPOSE

This single-arm, open-label study aimed to explore the effects of extended-release paliperidone on social and cognitive function in patients with schizophrenia.

METHODS

Paliperidone extended-release (flexible dose ranging from 3 to 12 mg/day orally) was administered for 24 weeks in patients with schizophrenia. Patient function was assessed using the personal and social performance scale, measurement and treatment research to improve cognition in schizophrenia initiative-consensus cognitive battery, positive and negative syndrome scale, and clinical global impression-severity.

RESULTS

Ninety patients were included in the full analysis set, while 72 patients were included in the per protocol set. The personal and social performance score was 54.3±14.3 at baseline, and significantly increased to 73.4±12.6 at week 24 (P<0.001). For the measurement and treatment research to improve cognition in schizophrenia initiative-consensus cognitive battery assessment, six of the nine individual subtests, six of the seven cognitive domains, and total cognitive scores improved significantly (P<0.05) between baseline and endpoint. positive and negative syndrome scale total scores and clinical global impression-severity scores decreased gradually (P<0.001) from week 4 to the conclusion of the study.

CONCLUSION

Paliperidone extended-release treatment significantly improves social and neurocognitive function as well as symptoms in Chinese patients with schizophrenia.

No difference in frontal cortical activity during an executive functioning task after acute doses of aripiprazole and haloperidol

Background: Aripiprazole is an atypical antipsychotic drug that is characterized by partial dopamine D2 receptor agonism. Its pharmacodynamic profile is proposed to be beneficial in the treatment of cognitive impairment, which is prevalent in psychotic disorders. This study compared brain activation characteristics produced by aripiprazole with that of haloperidol, a typical D2 receptor antagonist, during a task targeting executive functioning.

Methods: Healthy participants received an acute oral dose of haloperidol, aripiprazole or placebo before performing an executive functioning task while blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) was carried out.

Results: There was a tendency towards reduced performance in the aripiprazole group compared to the two other groups. The image analysis yielded a strong task-related BOLD-fMRI response within each group. An uncorrected between-group analysis showed that aripiprazole challenge resulted in stronger activation in the frontal and temporal gyri and the putamen compared with haloperidol challenge, but after correcting for multiple testing there was no significant group difference.

Conclusion: No significant group differences between aripiprazole and haloperidol in frontal cortical activation were obtained when corrected for multiple comparisons. This study is registered in ClinicalTrials.gov (identifier: 2009-016222-14).¹

Emotion processing in schizophrenia is state and trait dependent

BACKGROUND

Substantial evidence exists about emotion processing (EP) impairments in schizophrenia patients. However, whether these deficits are present primarily during psychosis (i.e., state dependent) or an integral part of the disorder (i.e., trait dependent) remains unclear.

METHODS

EP was assessed with the degraded facial affect recognition task in schizophrenia patients (N=521) and healthy controls (N=312) at baseline (T1) and after a three year follow-up (T2). In schizophrenia patients symptomatic remission was assessed with the Positive and Negative Syndrome Scale (PANSS) remission tool. Patients were divided into four groups: remission T1 and remission T2 (RR); remission T1 and non-remission T2 (RN); non-remission T1 and non-remission T2 (NN) and non-remission T1 and remission T2 (NR). Factorial repeated measures ANCOVA was used to compare EP performance over time between groups. Age, gender and general cognition were included as covariates.

RESULTS

Schizophrenia patients performed worse than healthy controls on EP at T1 (p=0.001). The patients that were in symptomatic remission at both time points (the RR group) performed worse than the healthy controls at T2 (p<0.001). Significant group×time interactions were found between RR and RN (p=0.001), and between NR and RN (p=0.04), indicating a differential EP performance over time. No group×time interaction was found between NN and NR.

CONCLUSION

The results show relatively poor EP performance in schizophrenia patients compared to healthy controls. EP performance in schizophrenia patients was associated with symptomatic remission. The results provide support for the hypothesis that EP deficits in schizophrenia are both state and trait dependent.

Oxytocin and social cognition in affective and psychotic disorders

Impairments in social cognition are now recognized as core illness features in psychotic and affective disorders. Despite the significant disability caused by social cognitive abnormalities, treatments for this symptom dimension are lacking. Here, we describe the evidence demonstrating abnormalities in social cognition in schizophrenia, major depressive disorder, and bipolar disorder, as well as the neurobiology of social cognition including the role of oxytocin. We then review clinical trials of oxytocin administration in psychotic and affective disorders and the impact of this agent on social cognition. To date, several studies have demonstrated that oxytocin may improve social cognition in schizophrenia; too few studies have been conducted in affective disorders to determine the effect of oxytocin on social cognition in these disorders. Future work is needed to clarify which aspects of social cognition may be improved with oxytocin treatment in psychotic and affective disorders.