The efficacy of cariprazine on cognition: a post hoc analysis from phase II/III clinical trials in bipolar mania, bipolar depression, and schizophrenia

A comparative study of cognitive function in young patients with bipolar disorder with and without non-suicidal self-injury

OBJECTIVE

Bipolar disorder (BD) is a chronic mental disorder characterized by alternating or mixed episodes of mania or hypomania and depression. Cognitive function impairment is a frequent associated feature of the disease. While many BD patients also engage in non-suicidal self-injury (NSSI), there is a lack of studies on the cognitive function of BD patients with NSSI. This study aimed to evaluate cognitive functioning of BD patients with NSSI and provide a clinical basis for the differential diagnosis and treatment of BD and NSSI.

METHODS

A total of 60 BD patients with NSSI, 60 BD patients without NSSI, and 60 healthy controls (HC) were selected for the study. All participants met the inclusion criteria and were not taking any medications, excluding the potential effects of medication on cognitive functions. The following neurocognitive tests were used to measure the cognitive functions in areas such as speed of processing, reasoning and problem solving, attention/vigilance, working memory, visual learning, and verbal learning: The Trail Making Test (TMT), Category Fluency, Digit Symbol Coding Test (DSCT), Brief Visuospatial Memory Test-Revised (BVMT-R), The Neuropsychological Assessment Battery Mazes (NABM), Wechsler Memory Scale Third Edition Spatial Span Test (WMS III-SST), Hopkins Verbal Learning Test-Revised (HVLTR) and Continuous Performance Test and Identical Prs (CPT-IP).

RESULTS

The findings indicated that BD patients with NSSI exhibited cognitive impairment in all measured cognitive domains. On the other hand, BD patients without NSSI showed less pronounced impairment in terms of speed of processing, but exhibited significant cognitive impairment in the remaining five areas compared to the HC group.

CONCLUSION

The study underscores the presence of cognitive impairment in BD, and the cognitive impairment is more severe in BD patients with NSSI compared to those without NSSI. In conclusion, both individuals with NSSI and those without NSSI in BD exhibit cognitive impairment, which provides ideas and strategies for using cognitive-behavioral therapy to treat BD and NSSI.

The improvement of motor symptoms in Huntington's disease during cariprazine treatment

BACKGROUND

Huntington's disease (HD) is a progressive neurodegenerative disease, characterised by motor disturbances and non-motor (i.e., psychiatric) symptoms. Motor symptoms are the hallmark features of HD and take many forms. Their emergence is related to alterations in striatal dopaminergic neurotransmission: dopamine levels increase in the early stages of the disease, while more advanced stages are characterised by reduced dopamine levels. Such a biphasic change potentially explains the alterations in motor symptoms: increased dopamine-production induces hyperkinetic movements early in the disease course, while depleted dopamine storage leads to hypokinetic symptoms in the advanced phase. Dopamine D2-D3 partial agonists could be a promising treatment option in HD, as they have the potential to either elevate or lower the surrounding dopamine levels if the levels are too low or too high, respectively, potentially offering symptom-relief across the illness-course. Therefore, the present study aimed at exploring the effects of cariprazine, a dopamine D2-D3 partial agonist with high affinity to D3 receptors, on motor symptoms associated with HD.

METHODS

This was a single-centre, retrospective study where sixteen patients received off-label cariprazine treatment for 12 weeks (1.5-3 mg/day). Motor symptoms were evaluated using the Motor Assessment of the Unified Huntington's Disease Rating Scale. Least Square (LS) Mean Changes from Baseline (BL) to Week 8 and Week 12 in the Total Motor Score (TMS) were analysed using the Mixed Model for Repeated Measures method. In addition, improvement from BL to Week 8 and 12 was calculated for all motor items.

RESULTS

Data of 16 patients were collected, but data of only 15 patients were analysed as one patient dropped out due to non-compliance. Significant changes were observed from BL to Week 8 (LS Mean Change: -9.4, p < 0.0001) and to Week 12 (LS Mean Change: -12.8, p < 0.0001) in the TMS. The improvement was captured in the majority of motor functions, excluding bradykinesia and gait. Mild akathisia was the most commonly reported side-effect, affecting 3 patients.

CONCLUSION

This is the first study investigating the effectiveness of a D2-D3 partial agonist, cariprazine, in the treatment of HD. The findings of this study revealed that cariprazine was effective in the treatment of a wide range of motor symptoms associated with HD.

Cariprazine in an Adolescent with Tourette Syndrome with Comorbid Attention Deficit Hyperactive Disorder and Depression: A Case Report

Tourette syndrome is a complex neuropsychiatric condition that manifests in childhood and is often associated with other psychiatric comorbidities. This case report describes a young male with Tourette syndrome with major depressive disorder and attention deficit hyperactivity disorder (ADHD) who experienced troublesome side effects due to his existing medications (escitalopram, risperidone, and methylphenidate). In order to control his tics, ameliorate depressive symptoms, and eliminate side effects of stiffness and sedation, risperidone was switched to cariprazine, a third-generation antipsychotic medication with D3-D2 partial agonism. In addition, the antidepressant dose was also increased. With the new combination, the patient reported good control of his tics, together with significant improvement in depressive symptoms and no side effects. Based on this case and the reviewed literature, cariprazine might be a viable option for patients with Tourette syndrome with other comorbid illnesses who are prone to side effects of medication.

Dopamine partial agonists: a discrete class of antipsychotics

Worldwide, there are now three marketed dopamine D2 partial agonists: aripiprazole, brexpiprazole and cariprazine. These three drugs share a number of properties other than their action at D2 receptors. Pharmacologically, they are 5HT2 antagonists and D3 and 5HT1A partial agonists but with little or no alpha-adrenergic, anticholinergic or antihistaminic activity. They also share a long duration of action. Clinically, D2 partial agonists are effective antipsychotics and generally have useful antimanic and antidepressant activity. They are usually well tolerated, causing akathisia and insomnia only at the start of treatment, and are non-sedating. These drugs also share a very low risk of increased prolactin and of weight gain and accompanying metabolic effects. They may also have a relatively low risk of tardive dyskinesia. There is some evidence that they are preferred by patients to dopamine antagonists. Individual dopamineD2 partial agonists have much in common and as a group they differ importantly from dopamine D2 antagonists. Dopamine D2 partial agonists should be considered a distinct class of antipsychotics.Key pointsD2 partial agonists share many pharmacological and clinical propertiesD2 partial agonists differ in several important respects from D2 antagonistsD2 partial agonists should be considered a discrete class of antipsychotics.

Cariprazine: an augmentation strategy for treatment-resistant schizophrenia with pro-cognitive and anti-hostility effects

Schizophrenia is a chronic mental health condition treated with antipsychotics. A significant number of patients fail to respond to standard treatment and develop treatment-resistant schizophrenia (TRS). The only current treatment for TRS is clozapine, which has significant side effects and may only be effective in 40% of cases. We describe two cases of patients with TRS who have failed multiple antipsychotic trials and have had extensive hospitalization history due to aggression/hostility. Both patients responded to dual antipsychotic therapy with a long-acting injectable antipsychotic plus cariprazine. Both patients demonstrated improvement in hostility and cognition/memory. Cariprazine's novel mechanism of action may allow it to be uniquely effective in dual antipsychotic therapy for TRS. Cariprazine has a higher affinity than dopamine for D3 receptors and has a 10-fold higher affinity for D3 than D2. This may contribute to its pro-cognitive and anti-hostility effects. Further studies are warranted to determine the role of cariprazine in TRS.

An update on potential pharmacotherapies for cognitive impairment in bipolar disorder

INTRODUCTION

Cognitive impairment is a core feature of bipolar disorder (BD) that impedes recovery by preventing the return to optimal socio-occupational functioning and reducing quality of life. Presently, there are no efficacious treatments for cognitive impairment in BD, but many pharmacological interventions are being considered as they have the potential to target the underlying pathophysiology of the disorder.

AREAS COVERED

This review summarizes the available evidence for pharmacological interventions for cognitive impairment in bipolar disorder. We searched PubMed, MedLine, and PsycInfo from inception to December 1^st, 2022. Traditional treatments, such as lithium, anticonvulsants (lamotrigine), antipsychotics (aripiprazole, asenapine, cariprazine, lurasidone, and olanzapine), antidepressants (vortioxetine, fluoxetine, and tianeptine) and psychostimulants (modafinil), and emerging interventions, such as acetylcholinesterase inhibitors (galantamine and donepezil), dopamine agonists (pramipexole), erythropoietin, glucocorticoid receptor antagonists (mifepristone), immune modulators (infliximab, minocycline and doxycycline), ketamine, metabolic agents (insulin, metformin, and liraglutide), probiotic supplements, and Withania somnifera are discussed.

EXPERT OPINION

The investigation of interventions for cognitive impairment in BD is a relatively under-researched area. In the past, methodological pitfalls in BD cognition trials have also been a critical limiting factor. Expanding on the existing literature and identifying novel pharmacological and non-pharmacological treatments for cognitive impairment in BD should be a priority.