Brain Stimulation for Schizophrenia

Overseen By Philip Gerretsen, MD, PhD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Centre for Addiction and Mental Health

Stay on Your Current Meds You can continue your current medications while participating

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 20

Duration: 2 weeks

106 Participants Needed

Trial Summary

What is the purpose of this trial?

This study seeks to explore the effects of transcranial direct current stimulation (tDCS), a non-invasive method of brain stimulation, as an adjunctive treatment to improve antipsychotic medication adherence in patients with schizophrenia (SCZ). The investigators hypothesize that 20 sessions of tDCS will improve medication nonadherence in patients with SCZ.

Will I have to stop taking my current medications?

The trial requires that you stay on a stable dose of your current antipsychotic and other medications for at least 2 months before and during the study.

What data supports the effectiveness of the treatment TDCS for schizophrenia?

Research shows that transcranial direct current stimulation (tDCS) can help reduce symptoms in people with schizophrenia, especially auditory hallucinations and negative symptoms. Studies have found improvements in cognitive functions like memory and attention, and tDCS is considered a safe and promising treatment option. ^{1 2 3 4 5}

Is transcranial direct current stimulation (tDCS) safe for humans?

Research shows that transcranial direct current stimulation (tDCS) is generally safe and well-tolerated in humans, including those with schizophrenia. ^{4 5 6 7 8}

How does the brain stimulation treatment differ from other treatments for schizophrenia?

This treatment, known as transcranial direct current stimulation (tDCS), is unique because it uses a non-invasive electrical current applied to the scalp to help reduce symptoms like auditory hallucinations and cognitive deficits in schizophrenia, especially for those who do not respond to traditional antipsychotic medications. ^{2 5 7 8 9}

Research Team

Philip Gerretsen, MD, PhD

Principal Investigator

Centre for Addiction and Mental Health

Eligibility Criteria

This trial is for adults with schizophrenia or schizoaffective disorder who are on a stable medication regimen and can consent to participate. It's not for pregnant individuals, those with certain learning difficulties, severe thought disorders, recent substance dependence (except caffeine/nicotine), metal implants/pacemakers, acute suicidal/homicidal thoughts, or other major medical/neurological illnesses.

Inclusion Criteria

My gender or race does not limit my participation.

I have been diagnosed with schizophrenia or schizoaffective disorder.

I've been on a steady dose of my psychiatric medication for 2+ months.

Exclusion Criteria

Metal implants or pacemaker precluding an MRI scan or other contraindications to MRI (eg., claustrophobia)

Formal thought disorder rating ≥3 on the Positive and Negative Syndrome Scale (PANSS) P2 conceptual disorganization item

You have been addicted to drugs or alcohol (except caffeine and nicotine) within the past month.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive transcranial direct current stimulation (tDCS) twice-daily for 10 days, excluding weekends, to improve medication adherence

2 weeks

20 sessions (in-person)

Follow-up

Participants are monitored for medication adherence and insight into psychosis for 3 months after the treatment phase

3 months

Regular assessments (in-person and virtual)

Treatment Details

Interventions

• TDCS

Trial Overview The study tests transcranial direct current stimulation (tDCS) as an additional treatment to help patients with schizophrenia stick to their antipsychotic medication schedule. Participants will receive either the active tDCS or a sham (fake) version in 20 sessions to compare effects on medication adherence.

Participant Groups

Group I: Active TDCS Experimental Treatment 1 Intervention

In the active condition, a constant current of 2 mA intensity will be applied for 20 min to the parietal regions, using P3 as the cathode and P4 as the anode.

Group II: Sham TDCS Placebo Group 1 Intervention

In the sham condition, stimulation will be administered using the same parameters at the site of active treatment, but the current will be turned off after 30 seconds.

Who Is Running the Clinical Trial?

Centre for Addiction and Mental Health

Lead Sponsor

Trials

388

Recruited

84,200+

Findings from Research

In a study involving nine patients with schizophrenia, the combination of transcranial direct current stimulation (tDCS) and cognitive training did not show significant improvements in psychotic symptoms as measured by the Positive and Negative Syndrome Scale (PANSS).

The lack of effectiveness suggests that this specific tDCS protocol may not enhance clinical outcomes in schizophrenia, highlighting the need for larger studies to explore the potential of electric and cognitive stimulation therapies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of transcranial direct current stimulation (tDCS) over the prefrontal cortex combined with cognitive training for treating schizophrenia: a sham-controlled randomized clinical trial. Shiozawa, P., Gomes, JS., Ducos, DV., et al.[2022]

In a study of 31 adults with schizophrenia experiencing medication-refractory auditory verbal hallucinations (AVH), transcranial direct current stimulation (tDCS) showed a moderate reduction in hallucinations, with a 25%-29% improvement by the end of the second week and an additional 10% improvement maintained over four months.

The study also noted a small but significant 11% improvement in overall symptoms as measured by the Positive and Negative Syndrome Scale (PANSS-N), indicating that tDCS may provide lasting benefits for patients with persistent AVH.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcranial direct current stimulation for refractory auditory hallucinations in schizophrenia: Acute and 16-week outcomes. Kumar, PNS., Krishnan, AG., Suresh, R., et al.[2022]

Transcranial direct current stimulation (tDCS) has shown promise in reducing treatment-resistant symptoms of schizophrenia, particularly auditory hallucinations, with an average symptom reduction of 34%.

tDCS also positively impacts cognitive functions such as learning, working memory, and attention in patients with schizophrenia, suggesting it may enhance overall cognitive performance alongside symptom relief.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcranial Direct Current Stimulation for the Treatment of Refractory Symptoms of Schizophrenia. Current Evidence and Future Directions. Mondino, M., Brunelin, J., Palm, U., et al.[2022]

Transcranial Direct Current Stimulation (tDCS) is confirmed to be a very safe and well-tolerated treatment for patients with paranoid schizophrenia, based on an analysis of 219 treatment sessions.

While mild to moderate adverse effects like itching, burning, and heat sensations were reported, they were transient and resolved quickly, indicating that tDCS can be administered with minimal risk to patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Tolerability and Safety of 219 Transcranial Direct Current Stimulation (TDCS) 2.0 mA Sessions in Adult Patients with Schizophrenia. Wysokiński, A.[2023]

Transcranial direct current stimulation (tDCS) is a low-cost and easy-to-use neuromodulation technique that may help patients with schizophrenia, particularly those experiencing treatment-resistant auditory verbal hallucinations (AVH) and cognitive deficits, although results have been inconclusive.

While tDCS has shown little to no adverse effects, its effectiveness for negative symptoms remains limited unless used with a higher frequency of sessions, indicating a need for further research to optimize treatment parameters.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Noninvasive direct current stimulation for schizophrenia: a review. Lindenmayer, JP., Fitapelli, B.[2021]

Transcranial direct current stimulation (tDCS) was applied to a woman with schizophrenia and a left prefrontal tissue lesion, but it did not improve her auditory verbal hallucinations or neuropsychological function after 20 sessions.

Electric field simulations indicated that the patient's brain showed lower activation in the dorsolateral prefrontal cortex compared to both a matched non-lesioned schizophrenia patient and healthy controls, suggesting that structural brain lesions may limit the efficacy of tDCS.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

tDCS for auditory verbal hallucinations in a case of schizophrenia and left frontal lesion: efield simulation and clinical results. Mezger, E., Brunoni, AR., Hasan, A., et al.[2021]

A systematic review of 12 clinical studies on transcranial direct current stimulation (tDCS) for schizophrenia revealed that the most common electrode setup involved placing the anode over the left dorsolateral prefrontal cortex and the cathode over the temporoparietal cortex.

Computer modeling predicted that this setup activates areas linked to negative symptoms and under-activates those associated with positive symptoms, suggesting that tDCS may target specific symptom profiles in schizophrenia.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Understanding tDCS effects in schizophrenia: a systematic review of clinical data and an integrated computation modeling analysis. Brunoni, AR., Shiozawa, P., Truong, D., et al.[2018]

References

1. Brazil pubmed.ncbi.nlm.nih.gov

Effect of transcranial direct current stimulation (tDCS) over the prefrontal cortex combined with cognitive training for treating schizophrenia: a sham-controlled randomized clinical trial. [2022]

2. India pubmed.ncbi.nlm.nih.gov

Transcranial direct current stimulation for refractory auditory hallucinations in schizophrenia: Acute and 16-week outcomes. [2022]

3. Korea (South) pubmed.ncbi.nlm.nih.gov

Transcranial direct current stimulation in schizophrenia. [2021]

4. England pubmed.ncbi.nlm.nih.gov

Prevention of schizophrenia deficits via non-invasive adolescent frontal cortex stimulation in rats. [2021]

5. United Arab Emirates pubmed.ncbi.nlm.nih.gov

Transcranial Direct Current Stimulation for the Treatment of Refractory Symptoms of Schizophrenia. Current Evidence and Future Directions. [2022]

6. Croatia pubmed.ncbi.nlm.nih.gov

Tolerability and Safety of 219 Transcranial Direct Current Stimulation (TDCS) 2.0 mA Sessions in Adult Patients with Schizophrenia. [2023]

7. United States pubmed.ncbi.nlm.nih.gov

Noninvasive direct current stimulation for schizophrenia: a review. [2021]

8. England pubmed.ncbi.nlm.nih.gov

tDCS for auditory verbal hallucinations in a case of schizophrenia and left frontal lesion: efield simulation and clinical results. [2021]

9. England pubmed.ncbi.nlm.nih.gov

Understanding tDCS effects in schizophrenia: a systematic review of clinical data and an integrated computation modeling analysis. [2018]