Schizophrenia
Conditions
Keywords
schizophrenia, EEG, tDCS, dorsolateral prefrontal cortex, temporoparietal junction, cognitive control, auditory hallucinations, transcranial direct current stimulation
Brief summary
The purpose of this study is to test the impact of non-invasive brain stimulation, transcranial direct current stimulation (tDCS), on auditory hallucinations, negative symptoms and cognition in schizophrenia. Clinical measures will be used to assess clinical symptoms and cognitive performance to test the hypothesis that a course of tDCS can reduce auditory hallucinations and negative symptoms in schizophrenia.
Interventions
DEVICETranscranial Direct Current Stimulation
In tDCS, saline-soaked electrodes are temporarily affixed to the scalp and connected to a battery-powered current generator. A weak (2 mA) constant current is then briefly applied (20 minutes) to stimulate the targeted brain area (e.g. the DLPFC, TPJ, Occipital Cortex) depending on the phase of the study.
Sponsors
University of California, Davis
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* Participants must be able to sufficiently speak and understand English so as to be able to understand and complete cognitive tasks. * All subjects must have the ability to give valid informed consent. * No children under the age of 18 will be recruited. * Diagnosis of schizophrenia, schizophreniform, or schizoaffective disorder * Stable outpatient or partial hospital status * Normal IQ (\>70; IQ will be measured by administering the Wechsler Abbreviated Scale of Intelligence (WASI) test)
Exclusion criteria
* Pacemakers * Implanted electrical (brain and spinal) stimulators * Implanted defibrillator * Metallic implants * Skin damage or skin conditions such as eczema at the sites where electrodes will be placed * Hair styles hindering the placement of electrodes * Cranial pathologies * Head trauma * Epilepsy * Mental retardation * Any known history of neurological disorders (including epilepsy, amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), stroke, cerebral palsy, any DSM-5 axis I psychiatric disorder (for healthy control subjects), autism) * Uncorrected vision problems that would hinder cognitive testing (this also pertains to subjects with color blindness in tasks where discriminating colored objects/items is necessary for successful performance) * Pregnancy * Substance dependence in the past six months * Substance abuse in the past month
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Symptom Severity of Auditory Hallucinations | Assessment begins with the initial baseline interview and concludes after a 2-week follow-up assessment using the same clinical measures. | Participants will undergo diagnostic (clinical) interviews to rate their symptom severity using measures including, but not limited to, the Brief Psychiatric Rating Scale (rated 1-7, with a high rating indicating more severe symptoms), the Scale of the Assessment of Positive Symptoms (rated 0-5, with a high rating indicating more severe symptoms), and the Scale for the Assessment or Negative Symptoms (rated 0-5, with a high rating indicating more severe symptoms). |
| Change in Symptom Severity of Negative Symptoms | Assessment begins with the initial baseline interview and concludes after a 2-week follow-up assessment using the same clinical measures. | Participants will undergo diagnostic (clinical) interviews to rate their symptom severity using measures including, but not limited to, the Brief Psychiatric Rating Scale (rated 1-7, with a high rating indicating more severe symptoms), the Scale of the Assessment of Positive Symptoms (rated 0-5, with a high rating indicating more severe symptoms), and the Scale for the Assessment or Negative Symptoms (rated 0-5, with a high rating indicating more severe symptoms). |
Countries
United States
Outcome results
None listed