Auditory Hallucinations, Schizoaffective Disorder, Schizophrenia
Conditions
Keywords
schizophrenia, auditory hallucinations, transcranial stimulation, tDCS, tACS
Brief summary
Investigating the effect of non-invasive transcranial current stimulation on auditory hallucinations in patients with schizophrenia. Normal neuronal activity is perturbed in schizophrenia, so selective targeting of this abnormal activity could serve as a treatment for schizophrenia and alleviate symptoms caused by abnormal neuronal activity, such as auditory hallucinations.
Detailed description
AIM 1: To evaluate the effect of transcranial direct current stimulation (tDCS) (2mA for 20min on five consecutive days) on auditory hallucinations in schizophrenia patients using the change in ratings on the Auditory Hallucination Rating Scale (AHRS) by patients before and after stimulation. We hypothesize that tDCS will modulate the abnormal neuronal activity found in schizophrenic patients and thereby decrease their auditory hallucinations when measured after stimulation. AIM 2: To evaluate the long term effects of tDCS by having patients give a rating on the AHRS after one month has passed since stimulation and comparing this value to their baseline score and their score immediately after stimulation. We hypothesize that there will remain a significant reduction in auditory hallucination score in participants who received tDCS at one month.
Interventions
DEVICEtDCS
DEVICESham stimulation
Sponsors
University of North Carolina, Chapel Hill
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Diagnostic and Statistical Manual IV (DSM-IV) diagnosis of schizophrenia, any subtype, or schizoaffective disorder, with refractory auditory hallucinations. Duration of illness \>1 year. * 18-99 years old. * Clinically stable for at least 12 weeks, i.e. not requiring hospitalization or a change in level of care . * On current antipsychotic doses for approximately 4 weeks or more. * Capacity to understand all relevant risks and potential benefits of the study (informed consent) OR has a legal guardian who can complete consent forms on the patients behalf * Right handed
Exclusion criteria
* Subjects with a DSM-IV diagnosis of alcohol or substance abuse (other than nicotine) within the last month or a DSM-IV diagnosis of alcohol or substance dependence (other than nicotine) within the last 6 months. * History of significant head injury/trauma, as defined by loss of consciousness for more than 1 hour, or recurring seizures, or requiring later cognitive rehabilitation or causing cognitive sequelae. * Prior brain surgery. * Any brain devices/implants, including cochlear implants and aneurysm clips. * Co-morbid neurological condition (i.e. seizure disorder, brain tumor). * Medical or neurological illness (unstable cardiac disease AIDS, malignancy, liver or renal impairment) or treatment for a medical disorder that could interfere with study participation. * Non English speakers. * Pregnancy, nursing, or if female and fertile, unwilling to use appropriate birth control measures during study participation
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Auditory Hallucination Rating Scale (AHRS)Score From Baseline to Day 5 | Baseline, Day 5 | Examining AHRS total score after 5 days of stimulation compared to baseline assessment total. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Persistence of Decrease in AHRS Score Over Time | Day 5, One month | We will re-assess patients one month after the completion of stimulation to evaluate whether their change from baseline to day 5 score on the AHRS persisted over time, namely 30 days. |
Countries
United States
Participant flow
Recruitment details
Patients recruited through medical providers. Providers knew inclusion/exclusion criteria and discussed the study with patients during their regular appointments. Interested participants contacted the study team. Participants recruited from the STEP clinic (Chapel Hill and Raleigh), and the Burlington ACT team. Recruitment between 4/14 and 9/14.
Pre-assignment details
Subjects randomly assigned to one of two groups, transcranial direct stimulation (tDCS) group or active sham group. tDCS group, direct current was delivered during awake, resting state for 20minutes on 5 consecutive days. Sham stimulation was delivered for an equal period of time and number of sessions. 27 subjects signed consent, 1 withdrew.
Participants by arm
| Arm | Count |
|---|---|
| Transcranial Direct Current Stimulation (tDCS) 13 subjects total. 2mA stimulation for 20 minutes.
tDCS | 13 |
| Sham Stimulation 13 subjects total. An initial 40sec of stimulation at 2mA followed by a small current pulse every 550msec for the remainder of the 20 minute period.
Sham stimulation | 13 |
| Total | 26 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Withdrawal by Subject | 1 | 0 |
Baseline characteristics
| Characteristic | Transcranial Direct Current Stimulation (tDCS) | Sham Stimulation | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 13 Participants | 13 Participants | 26 Participants |
| Age, Continuous | 43.38 years STANDARD_DEVIATION 12.64 | 40.00 years STANDARD_DEVIATION 10.74 | 41.69 years STANDARD_DEVIATION 11.62 |
| Auditory Hallucination Rating Scale | 27.00 units on a scale STANDARD_DEVIATION 6.9 | 26.69 units on a scale STANDARD_DEVIATION 6.3 | 26.85 units on a scale STANDARD_DEVIATION 6.48 |
| Positive and Negative Syndrome Scale | 73.15 units on a scale STANDARD_DEVIATION 12.9 | 66.92 units on a scale STANDARD_DEVIATION 17.17 | 70.04 units on a scale STANDARD_DEVIATION 15.21 |
| Region of Enrollment United States | 13 participants | 13 participants | 26 participants |
| Sex: Female, Male Female | 3 Participants | 1 Participants | 4 Participants |
| Sex: Female, Male Male | 10 Participants | 12 Participants | 22 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 13 | 0 / 13 |
| serious Total, serious adverse events | 0 / 13 | 0 / 13 |
Outcome results
Primary
Change in Auditory Hallucination Rating Scale (AHRS)Score From Baseline to Day 5
Examining AHRS total score after 5 days of stimulation compared to baseline assessment total.
Time frame: Baseline, Day 5
Population: Per protocol; All participants who completed every session of the study from the initial session through the one month follow-up.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Transcranial Direct Current Stimulation (tDCS) | Change in Auditory Hallucination Rating Scale (AHRS)Score From Baseline to Day 5 | -6.38 units on a scale | Standard Deviation 6.38 |
| Sham Stimulation | Change in Auditory Hallucination Rating Scale (AHRS)Score From Baseline to Day 5 | -8.54 units on a scale | Standard Deviation 8.68 |
Comparison: The null hypothesis was that there is no difference between the changes in the AHRS score from baseline to 5 days between the groups:~H0: μ1 = μ2 μ1: mean(difference 5 days-baseline) for tDCS group (n=13) μ2: mean(difference 5 days-baseline) for sham group (n=13)p-value: 0.48t-test, 2 sided
Secondary
Persistence of Decrease in AHRS Score Over Time
We will re-assess patients one month after the completion of stimulation to evaluate whether their change from baseline to day 5 score on the AHRS persisted over time, namely 30 days.
Time frame: Day 5, One month
Population: Per protocol; All participants who completed every session of the study from the initial session through the one month follow-up.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Transcranial Direct Current Stimulation (tDCS) | Persistence of Decrease in AHRS Score Over Time | -5.38 units on a scale | Standard Deviation 9.06 |
| Sham Stimulation | Persistence of Decrease in AHRS Score Over Time | -4.77 units on a scale | Standard Deviation 8.26 |
Comparison: The null hypothesis was that there is no difference between the AHRS score changes from baseline to 1month between the groups:~H0: μ1 = μ2 μ1: mean(difference 1 month-baseline) for tDCS group (n=13) μ2: mean(difference 1 month-baseline) for sham group (n=13)p-value: 0.86t-test, 2 sided