Can brexpiprazole be switched safely in patients with schizophrenia and dopamine supersensitivity psychosis? A retrospective analysis in a real-world clinical practice.

Background: Several studies have reported that a switch to the dopamine partial agonist (DPA) aripiprazole (ARP), especially when the switch is abrupt, is likely to fail and sometimes worsen psychosis in schizophrenia patients already under high-dose antipsychotic treatment. Such a switching failure is speculated to be related to be the dopamine supersensitivity state. The risks of switching to the DPA brexpiprazole (BREX) have not been reported.

Dopamine supersensitivity psychosis and delay of clozapine treatment in patients with treatment-resistant schizophrenia.

Both the underutilization of clozapine and treatment resistance of patients to clozapine are serious problems worldwide. Identifying clinical markers predicting response to clozapine would help clinicians more effectively utilize clozapine treatment. The present study retrospectively assessed dopamine supersensitivity psychosis (DSP) in addition to other measures such as age at disease onset and delay of clozapine introduction for a total of 47 treatment-resistant schizophrenia (TRS) patients.

Long-Term Treatment With Long-Acting Injectable Antipsychotic in Schizophrenia Patients With and Without Dopamine Supersensitivity Psychosis: A 6-Year Retrospective Comparative Study.

Background: Dopamine supersensitivity psychosis (DSP) is an unstable psychotic state in patients with schizophrenia due to an upregulation of dopamine D2 receptors induced by antipsychotic medication. Long-acting antipsychotic injectable (LAI) could be advantageous for controlling the dopamine supersensitivity state, but it is not known if long-term treatment with LAI might ultimately lead to development or exacerbation of DSP.

Methods: The present study included 58 patients who had been treated with LAI for at least 3 years, with medical records for the 3 years before its introduction.

A preliminary genetic association study of GAD1 and GABAB receptor genes in patients with treatment-resistant schizophrenia.

Background: GABAergic system dysfunction has been implicated in the etiology of schizophrenia and of cognitive impairments in particular. Patients with treatment-resistant schizophrenia (TRS) generally suffer from profound cognitive impairments in addition to severe positive symptoms, suggesting that GABA system dysfunction could be involved more closely in patients with TRS.

Methods And Results: In the present study, exome sequencing was conducted on fourteen TRS patients, whereby four SNPs were identified on GAD1, GABBR1 and GABBR2 genes.

Risk factors for early-phase clozapine discontinuation: A nested case-control study.

Objectives: Safe and efficient methods for introducing clozapine to patients with treatment-resistant schizophrenia (TRS) are needed. We investigated risk factors for clozapine discontinuation in the early phase of its introduction.

Methods: We conducted a nested case-control study at 14 psychiatric hospitals in Chiba, Japan.

Interacting Roles of COMT and GAD1 Genes in Patients with Treatment-Resistant Schizophrenia: a Genetic Association Study of Schizophrenia Patients and Healthy Controls.

The projection from dopaminergic neurons to gamma-aminobutyric acid (GABA) interneurons in the prefrontal cortex is involved in the etiology of schizophrenia. The impact of interacting effects between dopamine signals and the expression of GABA on the clinical phenotypes of schizophrenia has not been studied. Since these interactions could be closely involved in prefrontal cortex functions, patients with specific alleles of these relevant molecules (which lead to lower or vulnerable genetic functions) may develop treatment-refractory symptoms.