Schizophrenic PatientsNCT06538259
Effects of tDCS Combined With Retrieval Practice on Semantic Memory in Patients With Schizophrenia
A study testing Transcranial direct current stimulation (tDCS)-anodal group in people with Schizophrenic Patients, run by Northeast Normal University at 1 site in China.
Trial summary
The semantic processing deficit stands as a central feature of cognitive abnormalities in schizophrenia. Both transcranial direct current stimulation (tDCS) and retrieval practice have been demonstrated as external techniques capable of ameliorating the semantic processing deficit in individuals with schizophrenia. Read more about this study
- Who is it for?
- Ages 19 to 60 years
- Conditions the study is for
- Schizophrenic Patients
- What is being tested?
- Transcranial direct current stimulation (tDCS)-anodal group
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 52 participants
- Where
- 1 siteChina
- Study dates
- 24 Jul 2023to 15 Apr 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 19 to 60 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Meeting the diagnostic criteria for schizophrenia according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5);
- Aged 18 years or older, regardless of gender, with an educational level of elementary school or above;
- All patients received stable-level antipsychotic medication treatment, were in a stable phase of disease treatment, able to understand the testing requirements, and cooperated to complete all research tasks;
- No history of neurological disorders or other serious physical illnesses, and no history of intellectual disability;
- No color blindness, color weakness, or other color vision impairments, with normal vision or corrected vision.
Who cannot join
- Clear cognitive impairment caused by somatic or cerebral organic lesions, such as cerebrovascular diseases, traumatic brain injury, etc;
- Individuals with mental disorders caused by substance dependence or abuse, or the use of psychoactive substances;
- History of brain injury or other central nervous system-related organic diseases;
- Individuals at significant risk of suicide or harming others;
- Participation in similar experiments in the past 30 days prior to baseline.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Effects of Transcranial Direct Current Stimulation Combined With Retrieval Practice on Semantic Memory in Patients With Schizophrenia
The semantic processing deficit stands as a central feature of cognitive abnormalities in schizophrenia. Both transcranial direct current stimulation (tDCS) and retrieval practice have been demonstrated as external techniques capable of ameliorating the semantic processing deficit in individuals with schizophrenia. The inquiry examines whether the combined effect of tDCS and retrieval practice, following tDCS intervention targeting the left dorsolateral prefrontal cortex (L-DLPFC) in patients with schizophrenia, contributes to the preservation of semantic memory in these individuals.
Investigators recruited 52 patients diagnosed with schizophrenia from hospitals. After five consecutive days of tDCS intervention (2 mA × 20 mins, twice per day), Investigators administered a word list memorization task comparing retrieval practice and restudy strategies. Subsequently, Investigators observed their immediate and delayed memory performance through tests.
Read the detailed description
Treatment was administered by two examiners, and after a total of 10 sessions over 5 consecutive days, a final group of 52 patients participated in the learning and testing phase. Among them, 27 received anodal stimulation, while 25 received sham stimulation. Each participant of each stimulation type was involved in both learning conditions, meaning that all participants completed both retrieval and restudy learning and testing.
- Stimulation phase: In the anodal group, the anode was placed over the left DLPFC (F3), and the cathode was placed over the contralateral supraorbital area (FP2). A direct current of 2mA was applied for 20 minutes during each stimulation session. Stimulation was conducted twice a day, at 9 a.m. and 2 p.m., for 5 consecutive days, totaling 10 sessions. In the sham group, the stimulation parameters, including the stimulation site and duration, were identical to those of the anodal group. However, during the 10-second ramp-up and ramp-down periods before and after stimulation, patients were unaware that the current was turned off.
- Learning phase: The experimental procedure followed the classic retrieval practice paradigm, which included a learning phase and a final test phase. During the experiment, participants were informed that they would learn two lists of words. Subsequently, they might either learn the words again or complete a list recall test, and will be given a final test shortly thereafter. The learning of the retrieval practice list and the restudy list was conducted in a randomly balanced manner. Each word was presented for 5 seconds, with a 500-millisecond interval between words. To avoid providing secondary retrieval cues between examples, all words were shuffled pseudo-randomly within categories. Each list contained 17 words, consisting of 5 examples from each of the 3 experimental categories (15 experimental examples, 2 filler examples). The first and last words presented in each list were filler words, thus controlling for the primacy and recency effects on memory. For the retrieval practice list, participants underwent two learning sessions and two retrieval sessions (S-T-S-T). During retrieval, participants were instructed to write down all the words they had just remembered within 5 minutes. For the restudy list, participants underwent four study sessions (S-S-S-S). Between each learning cycle, participants completed a 3-minute simple arithmetic task (dispersed attention task).
- Testing phase:
Immediate Test: Participants were instructed to recall as many words as possible from the learned lists within 10 minutes after completing all learning tasks.
Delayed Test: Participants were informed to recall as many words as possible from the learned lists within 10 minutes 24 hours later.
- Conditions
- Schizophrenic Patients
- Being tested
- Transcranial direct current stimulation (tDCS)-anodal group, Transcranial direct current stimulation (tDCS)-sham group
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Transcranial direct current stimulation (tDCS)-anodal groupDevice
2mA/20mins/session; 2sessions/day,5days
Transcranial direct current stimulation (tDCS)-sham groupDevice
0mA/20mins/session; 2sessions/day,5days
| Study group | Role | What they receive |
|---|---|---|
| anodal group | Experimental | In the anodal group, the anode was placed over the left DLPFC (F3), and the cathode was placed over the contralateral supraorbital area (FP2). A direct current of 2mA was applied for 20 minutes during each stimulation session. Stimulation was conducted twice a day, at 9 a.m. and 2 p.m., for 5 consecutive days, totaling 10 sessions. Receives: Device: Transcranial direct current stimulation (tDCS)-anodal group |
| sham group | Sham comparator | In the sham group, the stimulation parameters, including the stimulation site and duration, were identical to those of the anodal group. However, during the 10-second ramp-up and ramp-down periods before and after stimulation, patients were unaware that the current was turned off. Receives: Device: Transcranial direct current stimulation (tDCS)-sham group |
What is being measured
The primary outcome is the main question the study is designed to answer.
The correct recall rate of word lists
The correct recall rate of word lists was calculated for each subject by the experimental assistant.
Measured: 5mins to 24 hours
Adjusted Ratio of Clustering (ARC)
Free recall organization was measured by the Adjusted Ratio of Clustering (ARC) scores
Measured: 5mins to 24 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Aug 2024
- Study start24 Jul 2023
- Primary completion30 Jan 2024
- Study completion15 Apr 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (7)Papers the sponsor has linked to this study.
- Other trials for Schizophrenic PatientsStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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 N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 52 participants (actual)
Sponsor and investigators
- Lead sponsor
- Northeast Normal University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Xiaofeng Ma, Northeast Normal University
- Investigators
- Xiaofeng Ma, Professor, Principal investigator, Northwest Normal University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06538259
- Sponsor's protocol ID
- No.2023023
- Status last verified
- Jul 2024
- First submitted
- 27 Jul 2024
- Last updated
- 5 Aug 2024
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Cavendish BA, de Lima MFR, Pericoli L, Buratto LG. Effects of combining retrieval practice and tDCS over long-term memory: A randomized controlled trial. Brain Cogn. 2022 Feb;156:105807. doi: 10.1016/j.bandc.2021.105807. Epub 2021 Dec 20.
PubMed 34949566Javadi AH, Walsh V. Transcranial direct current stimulation (tDCS) of the left dorsolateral prefrontal cortex modulates declarative memory. Brain Stimul. 2012 Jul;5(3):231-241. doi: 10.1016/j.brs.2011.06.007. Epub 2011 Jul 26.
PubMed 21840287Sreeraj VS, Bose A, Chhabra H, Shivakumar V, Agarwal SM, Narayanaswamy JC, Rao NP, Kesavan M, Varambally S, Venkatasubramanian G. Working memory performance with online-tDCS in schizophrenia: A randomized, double-blinded, sham-controlled, partial cross-over proof-of-concept study. Asian J Psychiatr. 2020 Apr;50:101946. doi: 10.1016/j.ajp.2020.101946. Epub 2020 Feb 11.
PubMed 32087502Guimond S, Hawco C, Lepage M. Prefrontal activity and impaired memory encoding strategies in schizophrenia. J Psychiatr Res. 2017 Aug;91:64-73. doi: 10.1016/j.jpsychires.2017.02.024. Epub 2017 Mar 8.
PubMed 28325680Kim J, Iwata Y, Plitman E, Caravaggio F, Chung JK, Shah P, Blumberger DM, Pollock BG, Remington G, Graff-Guerrero A, Gerretsen P. A meta-analysis of transcranial direct current stimulation for schizophrenia: "Is more better?". J Psychiatr Res. 2019 Mar;110:117-126. doi: 10.1016/j.jpsychires.2018.12.009. Epub 2018 Dec 10.
PubMed 30639917Jantzi C, Mengin AC, Serfaty D, Bacon E, Elowe J, Severac F, Meyer N, Berna F, Vidailhet P. Retrieval practice improves memory in patients with schizophrenia: new perspectives for cognitive remediation. BMC Psychiatry. 2019 Nov 11;19(1):355. doi: 10.1186/s12888-019-2341-y.
PubMed 31711448Pan W, Li T, Ma X, Huo X. Effects of transcranial direct current stimulation combined with retrieval practice on semantic memory in patients with schizophrenia. BMC Psychiatry. 2025 Mar 7;25(1):214. doi: 10.1186/s12888-025-06530-y.
PubMed 40055696
Study at a glance
From the registry record, last updated by the sponsor on 5 Aug 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Transcranial Direct Current Stimulation Combined With Retrieval Practice on Semantic Memory in Patients With Schizophrenia
- ClinicalTrials.gov ID
- NCT06538259
- Acronym / sponsor ID
- No.2023023
- Conditions
- Schizophrenic Patients
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 52 participants (actual)
- Lead sponsor
- Northeast Normal UniversityUniversity, hospital or other
- Study start
- 24 Jul 2023 (actual)
- Primary completion
- 30 Jan 2024 (actual)
- Study completion
- 15 Apr 2024 (actual)
- First posted
- 5 Aug 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The semantic processing deficit stands as a central feature of cognitive abnormalities in schizophrenia. Both transcranial direct current stimulation (tDCS) and retrieval practice have been demonstrated as external techniques capable of ameliorating the semantic processing deficit in individuals with schizophrenia. The inquiry examines whether the combined effect of tDCS and retrieval practice, following tDCS intervention targeting the left dorsolateral prefrontal cortex (L-DLPFC) in patients with schizophrenia, contributes to the preservation of semantic memory in these individuals.
Investigators recruited 52 patients diagnosed with schizophrenia from hospitals. After five consecutive days of tDCS intervention (2 mA × 20 mins, twice per day), Investigators administered a word list memorization task comparing retrieval practice and restudy strategies. Subsequently, Investigators observed their immediate and delayed memory performance through tests.
Detailed description
Treatment was administered by two examiners, and after a total of 10 sessions over 5 consecutive days, a final group of 52 patients participated in the learning and testing phase. Among them, 27 received anodal stimulation, while 25 received sham stimulation. Each participant of each stimulation type was involved in both learning conditions, meaning that all participants completed both retrieval and restudy learning and testing.
- Stimulation phase: In the anodal group, the anode was placed over the left DLPFC (F3), and the cathode was placed over the contralateral supraorbital area (FP2). A direct current of 2mA was applied for 20 minutes during each stimulation session. Stimulation was conducted twice a day, at 9 a.m. and 2 p.m., for 5 consecutive days, totaling 10 sessions. In the sham group, the stimulation parameters, including the stimulation site and duration, were identical to those of the anodal group. However, during the 10-second ramp-up and ramp-down periods before and after stimulation, patients were unaware that the current was turned off.
- Learning phase: The experimental procedure followed the classic retrieval practice paradigm, which included a learning phase and a final test phase. During the experiment, participants were informed that they would learn two lists of words. Subsequently, they might either learn the words again or complete a list recall test, and will be given a final test shortly thereafter. The learning of the retrieval practice list and the restudy list was conducted in a randomly balanced manner. Each word was presented for 5 seconds, with a 500-millisecond interval between words. To avoid providing secondary retrieval cues between examples, all words were shuffled pseudo-randomly within categories. Each list contained 17 words, consisting of 5 examples from each of the 3 experimental categories (15 experimental examples, 2 filler examples). The first and last words presented in each list were filler words, thus controlling for the primacy and recency effects on memory. For the retrieval practice list, participants underwent two learning sessions and two retrieval sessions (S-T-S-T). During retrieval, participants were instructed to write down all the words they had just remembered within 5 minutes. For the restudy list, participants underwent four study sessions (S-S-S-S). Between each learning cycle, participants completed a 3-minute simple arithmetic task (dispersed attention task).
- Testing phase:
Immediate Test: Participants were instructed to recall as many words as possible from the learned lists within 10 minutes after completing all learning tasks.
Delayed Test: Participants were informed to recall as many words as possible from the learned lists within 10 minutes 24 hours later.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| anodal group | Experimental | Device: Transcranial direct current stimulation (tDCS)-anodal groupIn the anodal group, the anode was placed over the left DLPFC (F3), and the cathode was placed over the contralateral supraorbital area (FP2). A direct current of 2mA was applied for 20 minutes during each stimulation session. Stimulation was conducted twice a day, at 9 a.m. and 2 p.m., for 5 consecutive days, totaling 10 sessions. |
| sham group | Sham comparator | Device: Transcranial direct current stimulation (tDCS)-sham groupIn the sham group, the stimulation parameters, including the stimulation site and duration, were identical to those of the anodal group. However, during the 10-second ramp-up and ramp-down periods before and after stimulation, patients were unaware that the current was turned off. |
Who may qualify
- Ages
- 19 to 60 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Meeting the diagnostic criteria for schizophrenia according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5);
- Aged 18 years or older, regardless of gender, with an educational level of elementary school or above;
- All patients received stable-level antipsychotic medication treatment, were in a stable phase of disease treatment, able to understand the testing requirements, and cooperated to complete all research tasks;
- No history of neurological disorders or other serious physical illnesses, and no history of intellectual disability;
- No color blindness, color weakness, or other color vision impairments, with normal vision or corrected vision.
Key exclusion criteria (5 listed)
- Clear cognitive impairment caused by somatic or cerebral organic lesions, such as cerebrovascular diseases, traumatic brain injury, etc;
- Individuals with mental disorders caused by substance dependence or abuse, or the use of psychoactive substances;
- History of brain injury or other central nervous system-related organic diseases;
- Individuals at significant risk of suicide or harming others;
- Participation in similar experiments in the past 30 days prior to baseline.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Transcranial direct current stimulation (tDCS)-anodal group2mA/20mins/session; 2sessions/day,5days | Device | anodal group |
| Transcranial direct current stimulation (tDCS)-sham group0mA/20mins/session; 2sessions/day,5days | Device | sham group |
Primary outcome
The correct recall rate of word lists
Time frame: 5mins to 24 hours
The correct recall rate of word lists was calculated for each subject by the experimental assistant.
Adjusted Ratio of Clustering (ARC)
Time frame: 5mins to 24 hours
Free recall organization was measured by the Adjusted Ratio of Clustering (ARC) scores
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Aug 2024.
- Background: PubMed 34949566Cavendish BA, de Lima MFR, Pericoli L, Buratto LG. Effects of combining retrieval practice and tDCS over long-term memory: A randomized controlled trial. Brain Cogn. 2022 Feb;156:105807. doi: 10.1016/j.bandc.2021.105807. Epub 2021 Dec 20.
- Background: PubMed 21840287Javadi AH, Walsh V. Transcranial direct current stimulation (tDCS) of the left dorsolateral prefrontal cortex modulates declarative memory. Brain Stimul. 2012 Jul;5(3):231-241. doi: 10.1016/j.brs.2011.06.007. Epub 2011 Jul 26.
- Background: PubMed 32087502Sreeraj VS, Bose A, Chhabra H, Shivakumar V, Agarwal SM, Narayanaswamy JC, Rao NP, Kesavan M, Varambally S, Venkatasubramanian G. Working memory performance with online-tDCS in schizophrenia: A randomized, double-blinded, sham-controlled, partial cross-over proof-of-concept study. Asian J Psychiatr. 2020 Apr;50:101946. doi: 10.1016/j.ajp.2020.101946. Epub 2020 Feb 11.
- Background: PubMed 28325680Guimond S, Hawco C, Lepage M. Prefrontal activity and impaired memory encoding strategies in schizophrenia. J Psychiatr Res. 2017 Aug;91:64-73. doi: 10.1016/j.jpsychires.2017.02.024. Epub 2017 Mar 8.
- Background: PubMed 30639917Kim J, Iwata Y, Plitman E, Caravaggio F, Chung JK, Shah P, Blumberger DM, Pollock BG, Remington G, Graff-Guerrero A, Gerretsen P. A meta-analysis of transcranial direct current stimulation for schizophrenia: "Is more better?". J Psychiatr Res. 2019 Mar;110:117-126. doi: 10.1016/j.jpsychires.2018.12.009. Epub 2018 Dec 10.
- Background: PubMed 31711448Jantzi C, Mengin AC, Serfaty D, Bacon E, Elowe J, Severac F, Meyer N, Berna F, Vidailhet P. Retrieval practice improves memory in patients with schizophrenia: new perspectives for cognitive remediation. BMC Psychiatry. 2019 Nov 11;19(1):355. doi: 10.1186/s12888-019-2341-y.
- Derived from this study: PubMed 40055696Pan W, Li T, Ma X, Huo X. Effects of transcranial direct current stimulation combined with retrieval practice on semantic memory in patients with schizophrenia. BMC Psychiatry. 2025 Mar 7;25(1):214. doi: 10.1186/s12888-025-06530-y.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Xiaofeng Ma, Professor principal investigator
Northwest Normal University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Transcranial direct current stimulation (tDCS)-anodal group in people with Schizophrenic Patients, run by Northeast Normal University at 1 site in China.
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 5 inclusion and 5 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: finished, as of the sponsor's last update on 5 Aug 2024. 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 China. 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.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The correct recall rate of word lists (time frame: 5mins to 24 hours). The study lists 2 primary outcomes in all. 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 NCT06538259, which also lists 7 linked publications.
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 5 Aug 2024.