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Study on Reducing Antipsychotic Dose vs. Maintenance Treatment for Patients with Schizophrenia Using Haloperidol Decanoate, Risperidone, and Amisulpride

Verified siteRegistered drugNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the effects of different treatment strategies for patients diagnosed with schizophrenia spectrum disorder. This includes conditions such as schizophrenia, schizophreniform disorder, schizoaffective disorder, or brief psychotic episodes. The study will compare two approaches: reducing the dose of antipsychotic medications or maintaining the current treatment. The medications involved in this study include haloperidol decanoate, risperidone, amisulpride (also known as APD421), loxapine succinate, flupentixol decanoate, pregabalin, chlorpromazine hydrochloride (also known as aminazine), levomepromazine hydrochloride, aripiprazole, pipotiazine palmitate, and fluoxetine hydrochloride.

The purpose of the study is to determine if there is a difference in the effectiveness of these two treatment strategies based on the type of psychotic symptoms a patient experiences. The study will last for up to 24 months, during which patients will be monitored to see how well they function in their daily lives. This will be assessed using a scale called the Personal and Social Performance Scale (PSP). Patients will have regular check-ins with their healthcare providers and a specialized evaluation team to track their progress.

Throughout the study, various aspects of the patients' health will be monitored, including any side effects from the medications, their overall well-being, and their quality of life. The study aims to provide insights into how personalized treatment plans can improve outcomes for individuals with schizophrenia spectrum disorders. The ultimate goal is to find the most effective way to manage these conditions while minimizing side effects and improving patients' quality of life.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial assessment

    Upon joining the study, an initial assessment will be conducted to confirm eligibility. This includes verifying the diagnosis of schizophrenia spectrum disorder and ensuring clinical stability for at least six months.

    The assessment will also involve evaluating the Personal and Social Performance Scale (PSP) score, which should be greater than 70.

  2. Step 2

    Treatment allocation

    Participants will be randomly assigned to one of two treatment strategies: dose reduction (DR) or maintenance treatment (MT).

    The allocation will be based on the participant's psychotic phenotype, categorized as either cycloid psychosis (CP) or non-cycloid psychosis.

  3. Step 3

    Medication administration

    Participants will receive medications such as haloperidol, risperidone, amisulpride, and others, depending on the treatment strategy assigned.

    Medications will be administered either orally or through intramuscular injection, with specific dosages and frequencies determined by the treatment plan.

  4. Step 4

    Regular assessments

    Throughout the study, regular assessments will be conducted to monitor clinical symptoms and treatment efficacy.

    These assessments will include the Personal and Social Performance Scale (PSP), Clinical Global Impression (CGI), and other relevant scales.

  5. Step 5

    Web-based evaluations

    At specific intervals, evaluations will be conducted via web meetings with the participant and their caregiver.

    These evaluations will focus on the participant's functioning and any changes in symptoms.

  6. Step 6

    Final assessment

    At the end of the study, a final assessment will be conducted to evaluate the participant's overall progress and treatment outcomes.

    This will include a structured interview to confirm the presence or absence of any relapses during the study period.

Who can join the trial?

12 criteria

  • Patient is between 18 and 60 years old.
  • Patient is clinically stabilized for at least 6 months, meaning they have low levels of certain symptoms.
  • Patient is being treated with oral antipsychotic medications, which are drugs used to manage psychosis.
  • Patient has a PSP score greater than 70 at the start of the study. PSP stands for Personal and Social Performance, which measures how well a person is functioning in daily life.
  • Patient is covered by health insurance.
  • Patient has been informed about the results of their preliminary medical examination.
  • Patient is able to understand the aims and risks of the research, with help from a legal guardian if needed.
  • Patient has signed an informed consent form, with assistance from a legal guardian if necessary.
  • Patient has a diagnosis of schizophrenia spectrum disorder (SSD), which includes conditions like schizophrenia, schizophreniform, schizoaffective disorder, or brief psychotic episode.
  • Patient has either a cycloid psychosis (CP) type or another type of psychotic condition.
  • Patient is an outpatient, meaning they are not staying in a hospital, and is being followed by a psychiatrist.
  • Patient has an identified caregiver who can provide support.

Who cannot join the trial?

3 criteria

  • Patients who do not have a diagnosis of schizophrenia spectrum disorder (SSD). This includes conditions like schizophrenia, schizophreniform, schizoaffective disorder, or a brief psychotic episode.
  • Patients who are not within the specified age range for the study.
  • Patients who are part of a vulnerable population, which means they might need special protection or care.
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Investigated drugs

Antipsychotics are medications used to manage and treat symptoms of schizophrenia and other similar mental health disorders. They work by affecting the balance of certain chemicals in the brain, which can help reduce symptoms like hallucinations, delusions, and disorganized thinking. In this clinical trial, the focus is on comparing two strategies: reducing the dose of antipsychotics or maintaining the current dose, to see which approach is more effective for patients with different types of psychotic symptoms.

What is already known about the treatment

Antipsychotic Medication – This medication is typically administered orally in the form of tablets or capsules. It is currently being studied in clinical trials to determine the best treatment strategy for individuals with schizophrenia spectrum disorders, such as schizophrenia, schizophreniform, schizoaffective disorder, or brief psychotic episodes. The main therapeutic use of this medication is to help manage symptoms of these disorders, such as hallucinations and delusions. At the molecular level, it works by altering the effects of neurotransmitters in the brain, particularly dopamine, to help stabilize mood and thought processes. It is classified pharmacologically as an antipsychotic.

Investigated diseases

  • Schizophrenia

    Schizophrenia is a chronic mental disorder characterized by distortions in thinking, perception, emotions, language, sense of self, and behavior. It often includes symptoms such as hallucinations, delusions, and disorganized thinking. The progression of schizophrenia can vary, with some individuals experiencing episodes of acute symptoms followed by periods of remission. Over time, cognitive and functional impairments may develop, affecting daily life and social interactions. The course of the disease can be influenced by various factors, including stress and substance use. Schizophrenia typically requires long-term management to help individuals maintain functionality.

  • Schizophreniform Disorder

    Schizophreniform disorder is a mental health condition with symptoms similar to schizophrenia, such as hallucinations, delusions, and disorganized speech. However, the duration of these symptoms is shorter, typically lasting between one to six months. If symptoms persist beyond six months, the diagnosis may change to schizophrenia. The disorder can disrupt daily functioning and social relationships during its active phase. The progression can vary, with some individuals recovering fully, while others may develop more chronic conditions. Early intervention can play a role in the outcome of the disorder.

  • Schizoaffective Disorder

    Schizoaffective disorder is a mental health condition that features symptoms of both schizophrenia and mood disorders, such as depression or bipolar disorder. Individuals may experience hallucinations or delusions alongside mood swings or depressive episodes. The disorder can lead to significant challenges in managing emotions and maintaining relationships. Symptoms can fluctuate, with periods of severe symptoms followed by times of improvement. The progression of schizoaffective disorder can vary widely among individuals. Long-term management is often necessary to address both psychotic and mood symptoms.

  • Brief Psychotic Disorder

    Brief psychotic disorder is characterized by the sudden onset of psychotic symptoms, such as hallucinations, delusions, or disorganized speech, lasting for at least one day but less than one month. The symptoms can be severe and may cause significant distress or impairment in social or occupational functioning. The disorder often follows a stressful event or trauma, but the exact cause is not always clear. Recovery is typically rapid, with a full return to previous levels of functioning once symptoms resolve. The disorder is considered acute and self-limiting, with a low likelihood of recurrence. Early intervention can help manage symptoms and support recovery.

Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-509558-80-00Protocol codeDREAMS-PHENEstimated enrolment288 patientsSponsorLes Hopitaux Universitaires De Strasbourg

sourced from the EU Clinical Trials Register and site verification

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