Strategies for Early Non-response to Antipsychotic Drugs in the Treatment of Acute-phase Schizophrenia

Brain Age Gap as a Predictor of Early Treatment Response and Functional Outcomes in First-Episode Schizophrenia: A Longitudinal Study: L'écart d'âge cérébral comme prédicteur de la réponse en début de traitement et des résultats fonctionnels dans un premier épisode de schizophrénie : une étude longitudinale

OBJECTIVES

Accelerated brain aging, i.e., the age-related structural changes in the brain appearing earlier than expected from one's chronological age, is a feature that is now well established in schizophrenia. Often interpreted as a feature of a progressive pathophysiological process that typifies schizophrenia, its prognostic relevance is still unclear. We investigate its role in response to antipsychotic treatment in first-episode schizophrenia.

METHODS

We recruited 49 drug-naive patients with schizophrenia who were then treated with risperidone at a standard dose range of 2-6 mg/day. We followed them up for 3 months to categorize their response status. We acquired T1-weighted anatomical images and used the XGboost method to evaluate individual brain age. The brain age gap (BAG) is the difference between the predicted brain age and chronological age.

RESULTS

Patients with FES had more pronounced BAG compared to healthy subjects, and this difference was primarily driven by those who did not respond adequately after 12 weeks of treatment. BAG did not worsen significantly over the 12-week period, indicating a lack of prominent brain-ageing effect induced by the early antipsychotic exposure per se. However, highly symptomatic patients had a more prominent increase in BAG, while patients with higher BAG when initiating treatment later showed lower gains in global functioning upon treatment, highlighting the prognostic value of BAG measures in FES.

CONCLUSIONS

Accelerated brain aging is a feature of first-episode schizophrenia that is more likely to be seen among those who will not respond adequately to first-line antipsychotic use. Given that early poor response indicates later treatment resistance, measuring BAG using structural MRI in the first 12 weeks of treatment initiation may provide useful prognostic information when considering second-line treatments in schizophrenia.

Differential effects of psychotropic drugs on microbiome composition and gastrointestinal function

RATIONALE

Growing evidence supports a role for the microbiota in regulating gut-brain interactions and, thus, psychiatric disorders. Despite substantial scientific efforts to delineate the mechanism of action of psychotropic medications at a central nervous system (CNS) level, there remains a critical lack of understanding on how these drugs might affect the microbiota and gut physiology.

OBJECTIVES

We investigated the antimicrobial activity of psychotropics against two bacterial strain residents in the human gut, Lactobacillus rhamnosus and Escherichia coli. In addition, we examined the impact of chronic treatment with these drugs on microbiota and intestinal parameters in the rat.

RESULTS

In vitro fluoxetine and escitalopram showed differential antimicrobial effects. Lithium, valproate and aripiprazole administration significantly increased microbial species richness and diversity, while the other treatments were not significantly different from controls. At the genus level, several species belonging to Clostridium, Peptoclostridium, Intestinibacter and Christenellaceae were increased following treatment with lithium, valproate and aripiprazole when compared to the control group. Animals treated with escitalopram, venlafaxine, fluoxetine and aripiprazole exhibited an increased permeability in the ileum.

CONCLUSIONS

These data show that psychotropic medications differentially influence the composition of gut microbiota in vivo and that fluoxetine and escitalopram have specific antimicrobial activity in vitro. Interestingly, drugs that significantly altered gut microbial composition did not increase intestinal permeability, suggesting that the two factors are not causally linked. Overall, unravelling the impact of psychotropics on gastrointestinal and microbiota measures offers the potential to provide critical insight into the mechanism of action and side effects of these medications.

Increased BOLD Signals Elicited by High Gamma Auditory Stimulation of the Left Auditory Cortex in Acute State Schizophrenia

Recent MRI studies have shown that schizophrenia is characterized by reductions in brain gray matter, which progress in the acute state of the disease. Cortical circuitry abnormalities in gamma oscillations, such as deficits in the auditory steady state response (ASSR) to gamma frequency (> 30-Hz) stimulation, have also been reported in schizophrenia patients. In the current study, we investigated neural responses during click stimulation by BOLD signals.

We acquired BOLD responses elicited by click trains of 20, 30, 40 and 80-Hz frequencies from 15 patients with acute episode schizophrenia (AESZ), 14 symptom-severity-matched patients with non-acute episode schizophrenia (NASZ), and 24 healthy controls (HC), assessed via a standard general linear-model-based analysis. The AESZ group showed significantly increased ASSR-BOLD signals to 80-Hz stimuli in the left auditory cortex compared with the HC and NASZ groups. In addition, enhanced 80-Hz ASSR-BOLD signals were associated with more severe auditory hallucination experiences in AESZ participants. The present results indicate that neural over activation occurs during 80-Hz auditory stimulation of the left auditory cortex in individuals with acute state schizophrenia. Given the possible association between abnormal gamma activity and increased glutamate levels, our data may reflect glutamate toxicity in the auditory cortex in the acute state of schizophrenia, which might lead to progressive changes in the left transverse temporal gyrus.

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We investigated neural responses during click stimulation by BOLD signals.

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We evaluated patients with acute and non-acute schizophrenia, and healthy controls.

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80-Hz auditory stimulation activated the left auditory cortex in acute schizophrenia.

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Our data may reflect left auditory cortex glutamate toxicity in acute schizophrenia.

Recent MRI studies show that schizophrenia is characterized by reduced brain gray matter, which deteriorates in the acute state of the disease. Periodic auditory click trains elicit auditory steady-state responses (ASSRs), and ASSR abnormalities are reported in schizophrenia. We investigated neural responses during click stimulation using BOLD signals, which may reflect glutamate toxicity. Compared with non-acute schizophrenia patients and healthy controls, acute episode schizophrenia patients showed significantly increased ASSR-BOLD to 80-Hz stimuli in the left auditory cortex. Our data demonstrate neuronal over activation in terms of the BOLD pattern in acute state schizophrenia, which might reflect progressive volume reduction in the left superior temporal cortex by glutamate toxicity during the acute phase of schizophrenia.

Treatment of early non-response in patients with schizophrenia: assessing the efficacy of antipsychotic dose escalation

BACKGROUND

Early non-response to antipsychotic treatment in patients with schizophrenia has been shown in multiple studies to predict poor response at short-term trial endpoint. Therefore, strategies to address the challenge of non-improvement early in the course of treatment are needed. A novel trial design was developed to assess the potential utility of antipsychotic dose escalation in patients with an inadequate initial treatment response. This design was embedded in a study intended to assess the efficacy of low dose lurasidone in patients with schizophrenia. The purpose of this report is to describe the background, rationale and design of this study that included a novel method for the assessment of the potential for dose-response in early non-responding patients with schizophrenia.

METHODS/DESIGN

In this 6-week, international, multicenter, double-blind trial, eligible adults with acute schizophrenia were randomized to receive fixed doses of lurasidone 20 mg/day, 80 mg/day (active control), or placebo in a 1:2:1 ratio. Patients initially randomized to lurasidone 80 mg/day who did not have a Positive and Negative Syndrome Scale total score improvement ≥ 20% at Week 2 were re-randomized on a 1:1 basis to receive either lurasidone 80 mg/day or lurasidone 160 mg/day for the remainder of the trial. All other groups remained on their initially assigned treatment. The formal primary objective of the study was to evaluate the efficacy of low-dose lurasidone (20 mg/day) compared to placebo; secondary objectives included evaluating the efficacy of lurasidone 80 mg/day versus 160 mg/day in early non-responders, and evaluating the efficacy of lurasidone in all subjects initially randomized to 80 mg/day versus placebo.

DISCUSSION

Since a lack of early improvement predicts poor response to short-term antipsychotic treatment in patients with schizophrenia, several treatment strategies have been proposed to enhance treatment outcome in early non-responders. A novel clinical trial design involving a placebo arm and re-randomization of early non-responders to increased or maintained antipsychotic dose was developed. The study design described in this report provides a robust method to assess the value of antipsychotic dose escalation in patients with schizophrenia who demonstrate poor initial treatment response.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01821378; initial registration March 22, 2013.