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Symptom, CognitivePhase 2NCT06340789

Neurotransmitters in Treatment Resistant Schizophrenia Patients With add-on Sodium Benzoate

A Phase 2 study testing Sodium Benzoate 2gram/day in people with Symptom, Cognitive and Schizophrenia, run by National Cheng-Kung University Hospital at 1 site in Taiwan.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

Although antipsychotic is effective for schizophrenia, however, still certain proportion of patients were not responsive to treatment. Treatment resistant schizophrenia (TRS) is accompanied by function decline and heavy burden. Read more about this study

Who is it for?
Ages 20 to 55 years
What is being tested?
Sodium Benzoate 2gram/day
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
90 participants
Where
1 siteTaiwan
Study dates
18 Nov 2021to 30 Apr 2028
Phase
Phase 2
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 20 to 55 years
  • All sexes
  • No healthy volunteers
  • Adult

Who may be able to join

  • Fulfil the DSM5 criteria for schizophrenia or schizoaffective disorder
  • Research criteria for treatment resistance: little or no symptomatic response to multiple (at least two) antipsychotic treatment of an adequate duration (at least 6 weeks) and adequate doses (equivalent to at least 600 milliequivalent (meq)/day of chlorpromazine)
  • 6 month period without remission (i.e. ≥4 item-score for the positive symptoms on PANSS scale , especially delusional thoughts, conceptual disorganisation, excitements, grandiosity, hallucinatory behaviour, excitement, persecution, and hostility)
  • The persistence of illness was defined as a score of ≥4 (moderately ill) on the severity of illness subscale of the Clinical Global Impression scale (CGI-S), and a lack of stable period of good social occupational function.

Who cannot join

  • Current or previous diagnosis of concurrent DSM-5 disorder due to active medical problems, known neurological disease, or a contraindication to MRI scanning
  • Current diagnosis of substance-related disorder
  • Any acute or chronic medical condition
  • History of head trauma or neurological diseases.

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Yen-Kuang Yang, Dr contact

+886-6-2353535 ext. 5202

ykyang@mail.ncku.edu.tw

Li- Chung Huang, Dr contact

0911889866

huanglichung@hotmail.com

Taiwan1 site, 1 recruiting

  • Taichung Veterans General Hospital Chiayi Branch

    Chiayi City, 600

    Dr. Huang, +886-5-2359630 ext.6106, huanglichung@hotmail.com

    Recruiting

Other trials in Taiwan

About this study

Official title: Functional Connectivity and Associated Neuropeptides Variations in Treatment Resistant Schizophrenia Patients: Treatment Efficacy of add-on Sodium Benzoate

Although antipsychotic is effective for schizophrenia, however, still certain proportion of patients were not responsive to treatment. Treatment resistant schizophrenia (TRS) is accompanied by function decline and heavy burden. In recent decades, the biological mechanism of schizophrenia extended from dopamine theory to the role of glutamate system. This shift could be an alternative pathway to developing the treatment of TRS. Sodium benzoate (SB) could be an option as a glutamatergic agent for the patients with TRS. However, most evidence of SB is for treating patients with schizophrenia and other mental disorders but the evidence for treating patients with TRS is scarce. To predict the treatment response of SB will be an urgent topic in the future. Little is known about the precise medicine for treating patients with TRS. The present project will extend our pilot randomized clinical trial on SB for TRS. A total of 90 patients with TRS will be enrolled from three centers and will be assigned to 8 weeks of treatment with SB or placebo (2:1). A comprehensive battery of potential markers will be employed, including 1H- magnetic resonance spectroscopy (MRS), brain functional connectivity, genotyping, immune biomarkers, cognitive function, and clinical characteristics. The efficacy of SB on TRS will be confirmed in this project. Predictors for treatment response will be identified. Artificial intelligence algorithms will be used for probing the feasibility of precision medicine.

Read the detailed description

The design and instrument are identical for two years. This add-on sodium benzoate randomized, double-blinded, placebo-controlled trial which is a two-arm, 6-week follow-up trial. The 90 patients will be 2:1 (SB: placebo) randomly assigned to 1. Treatment with sodium benzoate (A); or 2. placebo (P). The group of sodium benzoate treatment will be divided into two subgroups: 1. Responder (AR), and nonresponder (AN), as illustrated in Figure 4. The response criteria is defined the improvement of 20% total PANSS score after 6-week SB treatment. The participants with TRS will be enrolled in this trail from 3 hospitals(National Cheng Kung University Hospital, Tainan Hospital, Ministry of Health and Welfare, Chia-Yi branch, Taichung Veteran General Hospital).

Being tested
Sodium Benzoate 2gram/day, Placebo
Keywords
schizophrenia, sodium benzoate, cognition, treatment resistant schizophrenia
Medical subject headings
Neurobehavioral Manifestations, Schizophrenia, Psychotic Disorders, Schizophrenia, Treatment-Resistant

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Sodium Benzoate 2gram/dayDrug

    the add-on sodium benzoate with conventional pharmacological treatment

  • PlaceboDrug

    the add-on placebo with conventional pharmacological treatment

Study groups in NCT06340789
Study groupRoleWhat they receive
Treatment resistant schizophrenia patients with augmentation of sodium benzoate 2g/dayActive comparatorwith sodium benzoate 2g/day
Receives: Drug: Sodium Benzoate 2gram/day
Treatment resistant schizophrenia patients with augmentation of placeboPlacebo comparatorwith placebo
Receives: Drug: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Brain imaging, functional MRI

    All participants were scanned using a 1.5 Tesla GE scanner with eight channel head coils. 1H-MRS was performed to assess the concentrations of excitatory, glutamine, glutamate, glutamate complex (Glx), GABA and other neurometabolites. A three-dimensional T1-weighted inversion recovery magnetic resonance imaging (MRI) scan was performed in all participants, axial MRI three-dimensional brain volume, echo time (TE) = 2.9 ms, repetition time (TR) = 7.7, inversion time = 450 ms, flip angle = 12°, field of view =230 mm, matrix size = 256 × 256, and slice thickness = 1.0 mm

    Measured: 1hours

Secondary outcomes (4)

  1. Clinical psychiatric condition, Positive and Negative Symptoms Scale (PANSS)

    The PANSS is a clinical tool used to measure symptom severity in patients with schizophrenia. It takes approximately 45 minutes to interview a patient with schizophrenia using the PANSS. The patient is rated from 1 to 7 on 30 different symptoms based on the interview, as well as descriptions of caregivers or hospital workers. There are seven positive symptoms, seven negative symptoms, and 16 general psychopathological traits.

    Measured: 20 minutes

  2. Wechsler adult intelligence scales 4th edition (WAIS-IV)

    Specifically, for the cognitive function measurement, the WAIS-IV scale was used that comprises of five items: full-scale IQ (FSIQ), verbal comprehension index (VCI), perceptual reasoning index (PRI), WMI, and processing speed index (PSI), all of which are presented as different aspects of cognitive evaluation.

    Measured: 1 hours

  3. Continuous performance test third edition (CPT-3)

    The CPT-3, is a computer assessment that evaluates attention-related deficits generally performed in ADHD. The test requires examinees to press the space bar when any letter appears, except for the letter "X." The entire test has 360 trials and takes approximately 14 minutes to administer. CPT-3 yields 10 Tscores: Omissions (OM), Variability (VAR), Commissions (COM), Perseveration (PER), Detectability (DET), Response Style (RS), Hit Reaction Time (HRT), HRT Block Change (BC), HRT Standard Deviation (HRT SD), and HRT Inter-Stimulus Interval (ISI) change, based on four different domains of attention: inattentiveness, impulsivity, sustained attention, and vigilance. The CPT-3 also includes an internal validity check which notifies the administrator that the administration is invalid if the examinee had too few hits on targets, an omission rate higher than 25%, or if there was a timing problem regarding administration.

    Measured: 20 minutes

  4. Wisconsin card sorting test (WCST)

    WCST Computer Version 4-Research Edition was used in this study, and patients were required to match response cards to four stimulus cards along one of three dimensions (colour, form, or number) on the basis of verbal feedback (correct or wrong) without providing any information about the dimensions. Once the subject sorted a series of 10 cards into one category, the subject was asked to sort the cards again by a different category. In the present study, 64 cards were used. All definitions of the indices have been described in the WCST manual.

    Measured: 20 minutes

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted2 Apr 2024
  2. Study start18 Nov 2021
  3. Primary completion30 Apr 2028 (estimated)
  4. Study completion30 Apr 2028 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Model description
The design and instrument are identical for two years. This add-on sodium benzoate randomized, double-blinded, placebo-controlled trial which is a two-arm, 6-week follow-up trial. The 90 patients will be 2:1 (SB: placebo) randomly assigned to 1. Treatment with sodium benzoate (A); or 2. placebo (P). The group of sodium benzoate treatment will be divided into two subgroups: 1. Responder (AR), and nonresponder (AN), as illustrated in Figure 4. The response criteria is defined the improvement of 20% total PANSS score after 6-week SB treatment. The participants with TRS will be enrolled in this trail from 3 hospitals(National Cheng Kung University Hospital, Tainan Hospital, Ministry of Health and Welfare, Chia-Yi branch, Taichung Veteran General Hospital).
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
90 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06340789
Sponsor's protocol ID
A-BR-110-049
Status last verified
Mar 2026
First submitted
3 Nov 2021
Last updated
16 Jun 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Sodium Benzoate 2gram/day in people with Symptom, Cognitive and Schizophrenia, run by National Cheng-Kung University Hospital at 1 site in Taiwan.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 16 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Taiwan. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Yen-Kuang Yang, Dr (+886-6-2353535 ext. 5202, ykyang@mail.ncku.edu.tw), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Brain imaging, functional MRI (time frame: 1hours). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT06340789.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 16 Jun 2026.

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