Cognitive-enhancing effects of aripiprazole: a case report

Dopamine D1- and D2-like receptors oppositely regulate lifespan via a dietary restriction mechanism in Caenorhabditis elegans

BACKGROUND

Despite recent progress in understanding the molecular mechanisms regulating aging and lifespan, and the pathways involved being conserved in different species, a full understanding of the aging process has not been reached. In particular, increasing evidence suggests an active role for the nervous system in lifespan regulation, with sensory neurons, as well as serotonin and GABA signaling, having been shown to regulate lifespan in Caenorhabditis elegans (C. elegans). However, the contribution of additional neural factors, and a broad understanding of the role of the nervous system in regulating aging remains to be established. Here, we examine the impact of the dopamine system in regulating aging in C. elegans.

RESULTS

We report that mutations of DOP-4, a dopamine D1-like receptor (D1R), and DOP-2, a dopamine D2-like receptor (D2R) oppositely affected lifespan, fast body movement span, reproductive lifespan, and developmental rate in C. elegans. Activation of D2R using aripiprazole, an antipsychotic drug, robustly extended both lifespan and healthspan. Conversely, inhibition of D2R using quetiapine shortened worm lifespan, further supporting the role of dopamine receptors in lifespan regulation. Mechanistically, D2R signaling regulates lifespan through a dietary restriction mechanism mediated by the AAK-2-DAF-16 pathway. The DAG-PKC/PKD pathway links signaling between dopamine receptors and the downstream AAK-2-DAF-16 pathway to transmit longevity signals.

CONCLUSIONS

These data demonstrated a novel role of dopamine receptors in lifespan and dietary restriction regulation. The clinically approved antipsychotic aripiprazole holds potential as a novel anti-aging drug.

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.

Long Acting Polycaprolactone Based Parenteral Formulation of Aripiprazole Targeting Behavioural and Biochemical Deficit in Schizophrenia

Schizophrenia is a neurodevelopmental disorder which is expressed in the form of disturbed behaviour and abnormal mental functions. Patient's non-adherence to the medicine is the main cause of failure of drug therapy and increases incidence of relapses. Thus, for successful management of disease long acting parenteral formulations were developed. Aripiprazole was encapsulated in biocompatible polycaprolactone microsphere by o/w emulsion solvent-evaporation method in order to achieve sustained release of the drug for several weeks after single subcutaneous administration. They were optimised on the basis of various parameters such as physical appearance, particle size (49.4 μm-387.1 μm), encapsulation efficiency (70%-95%), percentage yield (33%-75%) and drug loading (25.9%-47.5%). The surface topography and sphericity of the microspheres was determined by scanning electron microscopy which revealed that the microspheres formed were spherical and non-porous in nature. The in vitro releases from the selected formulations were found to be 87% and 95% respectively after 45 days of dissolution. In vivo efficacy of optimised formulation showed significantly (p < 0.05) amelioration of various positive, negative and cognitive symptoms associated with schizophrenia and oxidative stress markers in ketamine-induced schizophrenia model in rats for 30 days.

Aripiprazole for the treatment of psychotic symptoms in patients with dementia with Lewy bodies: a case series

PURPOSE

The core features of dementia with Lewy bodies (DLB) are cognitive fluctuations, visual hallucinations, and parkinsonian symptoms. Although there have been several reports on the efficacy of treatments for psychotic symptoms in patients with DLB, little is known regarding the treatment effects of aripiprazole. The aim of this study was to evaluate the efficacy and safety of aripiprazole for the treatment of psychotic symptoms in patients with DLB.

PATIENTS AND METHODS

We employed a 10-week, open-label study design with 11 patients who met the criteria for DLB. The patients had previously experienced persistent or intermittent delusions, hallucinations, or both for at least 1 month. Aripiprazole was initiated at a low dose (3 or 6 mg/day) and titrated to higher doses at 2-week intervals or more rapidly, as needed. The Neuropsychiatric Inventory (NPI), Brief Psychiatric Rating Scale (BPRS), and Clinical Global Impression-Severity (CGI-S) were administered at baseline and 1, 2, 4, 8, and 10 weeks later. The Simpson-Angus Scale (SAS), Clinical Dementia Rating (CDR), and Mini-Mental State Examination (MMSE) Scale were evaluated at baseline and at week 10. The NPI, CGI-S, and BPRS scores were compared between the baseline and each assessment point and between each assessment point and the one before assessment point. The SAS, CDR, and MMSE scores were compared between the baseline and the end point.

RESULTS

The mean NPI and BPRS scores improved until the fourth week; they significantly decreased at each assessment point compared to the previous one. Afterward, improvements slowed and continued without significant decrease. The median SAS scores significantly decreased at the end point compared to the baseline (P<0.05). The median MMSE score was higher at the end point than at the baseline (P<0.05).

CONCLUSION

This study showed that aripiprazole may be effective and well tolerated for the treatment of psychotic symptoms in patients with DLB.

Coadministration of tramadol with aripiprazole and venlafaxine--The effect on spatial memory functions in male rats

BACKGROUND

The impairment of memory functions is very common in patients with chronic pain, particularly in patients with existing cognitive disorders. Results of some studies confirmed that tramadol (TRM), a frequently prescribed analgesic drug, improves memory functions in humans. However, there are no studies on the effect of co-administration of TRM with antidepressants or antipsychotics on memory; therefore, the aim of this study was to evaluate the effect of concomitant use of TRM with a second generation antipsychotic-aripiprazole (ARI) and an antidepressant-venlafaxine (VEN) on memory using an animal model.

METHODS

The effect of TRM (5mg/kg)+ARI (1.5mg/kg) and TRM (5mg/kg)+VEN (20mg/kg) on memory in Wistar rats was examined using the Morris water maze test after single and chronic administration (7 and 14 days).

RESULTS

It was observed that a single and chronic administration of TRM, VEN or ARI alone, but not a combination of TRM+VEN or TRM+ARI (except for 14 days of treatment) can improve memory in rats compared to the control group. After 14 days of administration, both combinations achieved improvement similar to each drug individually and improved spatial memory in rats compared to the control animals.

CONCLUSION

It can be assumed that chronic treatment with combinations of TRM+VEN or TRM+ARI is unlikely to cause memory impairment and interfere with either any antidepressant effect of VEN or any antipsychotic effect of ARI in patients suffering from chronic pain using TRM.

Cognitive effects of atypical antipsychotic drugs in first-episode drug-naïve schizophrenic patients

Cognitive impairment is a core feature of schizophrenia. The present randomized open study enrolled antipsychotic-naïve patients who were experiencing their first episode of schizophrenia. After baseline neurocognitive tests and clinical assessment, subjects were randomly assigned to olanzapine, risperidone and aripiprazole treatment groups. A battery of neurocognitive tests showed that risperidone produced cognitive benefits in all five cognitive domains, including verbal learning and memory, visual learning and memory, working memory, processing speed, and selective attention; olanzapine improved processing speed and selective attention; and aripiprazole improved visual learning and memory, and working memory. However, the three atypical antipsychotic drugs failed to reveal any significant differences in the composite cognitive scores at the study endpoint. In addition, the three drugs all significantly improved clinical measures without significant differences between the drugs after 6 months. These results suggest that the atypical antipsychotics, olanzapine, risperidone and aripiprazole may improve specific cognitive domains with similar global clinical efficacy. In clinical practice, it may be feasible to choose corresponding atypical antipsychotics according to impaired cognitive domains.

Effect of aripiprazole on cognitive function and hyperprolactinemia in patients with schizophrenia treated with risperidone

Objective

This study aimed to assess the efficacy of aripiprazole for the management of cognitive impairments and hyperprolactinemia in patients with schizophrenia on a stable dose of risperidone.

Methods

Thirty-five subjects stabilized on risperidone (3-6 mg/day) for a minimum of 3 months were enrolled in a double-blind, placebo-controlled phase for 12 weeks and an open-label phase for another 12 weeks. Subjects were randomly assigned to receive 10 mg/day aripiprazole (n=17) or placebo (n=18). Over the following 12 weeks, the the aripiprazole group received a flexible dose of aripiprazole while tapering risperidone. At baseline, week 12, and week 24, subjects were evaluated using the Positive and Negative Syndrome Scale (PANSS), Extrapyramidal Syndrome Rating Scale (ESRS), and standardized neuropsychological assessments. Serum prolactin levels were checked at baseline, week 1, week 2, and week 24.

Results

The mean change in total PANSS and cognitive function test scores between baseline and endpoint were similar in the aripiprazole and placebo groups. Scores on the ESRS and negative subscale of PANSS differed significantly between groups in both phases of the study (p<0.05), indicating a positive effect of aripiprazole. Compared with placebo, aripiprazole significantly reduced mean baseline serum prolactin levels within 1 week (p=0.015).

Conclusion

Adjunctive treatment with and switching to aripiprazole were not associated with improved cognitive function in patients with schizophrenia receiving risperidone; however, aripiprazole treatment decreased negative symptoms and risperidone-induced motor side effects and lowered serum prolactin levels.

Effect of adjunctive treatment with aripiprazole to atypical antipsychotics on cognitive function in schizophrenia patients

Second-generation antipsychotics yield only a modest improvement in cognitive benefit compared to first-generation antipsychotics. Aripiprazole, which is a partial dopamine D2 receptor agonist, may have an impact on cognitive dysfunction in patients with schizophrenia. This study administered aripiprazole or placebo to 36 outpatients with schizophrenia also receiving risperidone or olanzapine for 12 weeks in a double-blind, randomized, placebo-controlled study. Cognitive function was evaluated using the Brief Assessment of Cognition in Schizophrenia (BACS) just prior to drug administration as well as 12 weeks after. The PANSS and UKU side effect rating scales were used to evaluate the clinical response to additional treatment with aripiprazole. In a primary analyses, ANCOVA showed that there was an interaction between the treatment group and time for verbal fluency (p < 0.05), but not for any domain in BACS, PANSS or UKU side effect rating scales. Upon secondary analysis, however, the ameliorative change in motor speed as assessed by the BACS (p < 0.05) for those receiving aripiprazole was greater than that for the placebo group, whereas deterioration in verbal fluency (p < 0.01) and executive function (p < 0.01) in those receiving aripiprazole was significantly greater than in the placebo group. These results suggest that adjunctive treatment with aripiprazole improves motor speed but worsens some cognitive functions. It is likely that these effects are due to the dopamine D2 antagonistic effect of aripiprazole.

Effect of aripiprazole augmentation of clozapine in schizophrenia: a double-blind, placebo-controlled study

The simultaneous prescription of two or more antipsychotic drugs in combination is a common treatment strategy for those patients who have demonstrated a suboptimal response to clozapine; nevertheless, evidence suggesting potential advantages of combination treatment with clozapine plus one antipsychotic in terms of efficacy and tolerability are still sparse. The present 24-week double-blind, randomized, placebo-controlled trial of adjunctive aripiprazole to clozapine therapy in schizophrenia was aimed to explore the efficacy of aripiprazole add-on pharmacotherapy on clinical symptomatology and cognitive functioning in a sample of patients with treatment-resistant schizophrenia receiving clozapine. After clinical and neurocognitive assessments patients were randomly allocated to receive, in a double-blind design, either up to 15 mg/day of aripiprazole or a placebo. A final sample of thirty-one patients completed the study. The results obtained indicate that aripiprazole added to stable clozapine treatment showed a beneficial effect on the positive and general psychopathological symptomatology in a sample of treatment-resistant schizophrenia patients. Regarding executive cognitive functions, aripiprazole augmentation of clozapine had no significant effects. The findings provide evidence that aripiprazole augmentation of clozapine treatment is well-tolerated and may be of benefit for patients who are partially responsive to clozapine monotherapy; further double-blind, placebo-controlled trials in a larger number of patients are required to evaluate the therapeutic potential of aripiprazole augmentation of clozapine.

Effect of aripiprazole augmentation of serotonin reuptake inhibitors or clomipramine in treatment-resistant obsessive-compulsive disorder: a double-blind, placebo-controlled study

Based on the evidence that aripiprazole added to serotonin reuptake inhibitors (SRIs) or clomipramine in treatment-resistant obsessive-compulsive disorder (OCD) has reported promising results, the present 16-week, double-blind, randomized, placebo-controlled trial had the aim to explore the efficacy of aripiprazole add-on pharmacotherapy on clinical symptoms and cognitive functioning in a sample of treatment-resistant OCD patients receiving SRIs. After clinical and neurocognitive assessments, patients were randomly allocated to receive, in a double-blind design, 15 mg/d of aripiprazole or a placebo. A final sample of 30 patients completed the study. The results obtained indicate that aripiprazole added to stable SRI treatment substantially improved obsessive-compulsive symptoms as measured by changes on the Yale-Brown Obsessive Compulsive Scale total score and subscores (obsessions, P = 0.007; compulsions, P = 0.001; total score, P < 0.0001). Regarding cognitive functions, improvement was observed in some explored areas, such as attentional resistance to interference (Stroop score, P = 0.001) and executive functioning (perseverative errors, P = 0.015). The findings provide evidence that aripiprazole augmentation of SRIs/clomipramine treatment is well tolerated and may be proposed as an effective therapeutic strategy to improve outcome in treatment-resistant OCD.

Neurocognition and its influencing factors in the treatment of schizophrenia-effects of aripiprazole, olanzapine, quetiapine and risperidone

BACKGROUND

To examine influencing variables of neurocognition in patients with schizophrenia and to predict cognition during antipsychotic treatment.

METHODS

Data were obtained from patients with an acute episode of schizophrenia participating in two double-blind and one open label trial comparing the effects of different atypical antipsychotics on cognition. In total, 129 patients were enrolled in this analysis. Cognitive function was assessed at admission, week 4 and 8. Efficacy and tolerability were assessed weekly using the Positive and Negative Syndrome Scale (PANSS) and the Simpson Angus Sale (SAS). Patients were treated with aripirazole, olanzapine, quetiapine and risperidone. Regression analysis including mixed effect models was performed.

RESULTS

A significant improvement in all cognitive domains was observed from baseline to week 8. Regarding the antipsychotic treatment applied quetiapine seemed to achieve the most favourable cognitive improvement. Negative and depressive symptoms, the patient's age and the concomitant and antipsychotic treatment applied were observed to significantly influence and predict neurocognition.

CONCLUSION

The results may indicate that schizophrenia is a static disorder with trait and state dependent cognitive components especially in the memory domains. The influence of negative and depressive symptoms should be considered in daily clinical routine.