The Neural, Behavioural, and Cognitive Outcomes of Transcranial Direct Current Stimulation (tDCS) for Persistent Auditory Verbal Hallucinations in Schizophrenia
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Auditory Hallucination, Verbal
- Sponsor
- University of Ottawa
- Enrollment
- 84
- Locations
- 1
- Primary Endpoint
- Change in auditory hallucination severity measured by the Psychotic Symptom Rating Scale (PSYRATS)
- Last Updated
- 6 years ago
Overview
Brief Summary
Many individuals with schizophrenia struggle with auditory verbal hallucinations (AVHs). In some cases, these AVHs can be resistant to medication treatment. Previous research has found that transcranial direct current stimulation (tDCS) can be helpful in treating symptoms in individuals with other psychiatric disorders, such as depression. This study will assess if tDCS is effective in treating AVHs in individuals with schizophrenia. tDCS is a non-invasive form of brain stimulation which uses a weak current to temporarily excite or inhibit underlying cortical regions with small electrodes placed on the scalp. tDCS has been found to improve mental processes, including attention and memory function. In addition to examining the effect of tDCS on AVHs, this study will assess the effects of tDCS on mood as well as brain electrical activity with electroencephalogram (EEG) recordings. As an additional component, participants will be invited to participate in neuroimaging. Using magnetic resonance imaging (MRI), brain activity and structure will be examined before and after tDCS. tDCS will be administered twice daily for 5 consecutive days for a total of 10 sessions. These study findings will contribute to the understanding of the impact of tDCS on AVHs, and will also increase knowledge of sound and memory/cognitive processing in individuals with schizophrenia.
Investigators
Dr. Verner Knott
Senior Scientist
University of Ottawa
Eligibility Criteria
Inclusion Criteria
- •Primary diagnosis of schizophrenia or schizoaffective disorder
- •Clinically stable (discretion of psychiatrist)
- •Consistent history of AVHs over the course of illness
- •\>3 AVHs per week
- •Positive and Negative Syndrome Scale (PANSS) score of \>3
- •Primary medications limited to one of the atypical antipsychotics (medications stabilized for 4 weeks prior to enrollment)
Exclusion Criteria
- •Experiencing an acute psychotic episode
- •Current drug/alcohol dependence
- •Significant medical illness \& mental retardation/learning disability
- •Extra-pyramidal symptoms resulting in disordered movement
- •Abnormal audiometric assessment (thresholds for pure tones \>25 dB)
- •History of significant neurological issues \& head injuries/concussions resulting in loss of consciousness for \>5 minutes
- •Healthy Controls - Inclusion Criteria:
- •In good physical health
- •No history of serious mental health issues
- •Healthy Controls - Exclusion Criteria:
Outcomes
Primary Outcomes
Change in auditory hallucination severity measured by the Psychotic Symptom Rating Scale (PSYRATS)
Time Frame: Baseline, after 2nd tDCS session on days 1, 3, and 5, and follow-up (within a week of completing tDCS)
The PSYRATS is a multidimensional measure of auditory hallucinations, including 11 items rated on five-point (0-4) scales (total score range 0-44). Symptoms are rated over the last week, with higher scores reflecting more severe symptoms. The dimensions assessed are frequency, duration, location, loudness, beliefs about origin, negative content, intensity of negative content, amount of distress, intensity of distress, disruption of life and control.
Secondary Outcomes
- Change in Electroencephalography (EEG) - Resting-State Theta Power(3 weeks (baseline to follow-up))
- Change in Electroencephalography (EEG) - Mismatch Negativity (MMN)(3 weeks (baseline to follow-up))
- Change in Cambridge Neuropsychological Test Automated Battery (CANTAB) Schizophrenia Battery(3 weeks (baseline to follow-up))
- Change in Social Cognition - Social Attribution Task(3 weeks (baseline to follow-up))
- Change in Electroencephalography (EEG) - Resting-State Alpha Power(3 weeks (baseline to follow-up))
- Change in Beliefs about Voices Questionnaire-Revised (BAVQ-R) Scores(3 weeks (baseline to follow-up))
- Change in Voice Power Differential Scale (VPDS) Scores(3 weeks (baseline to follow-up))
- Change in Voices Acceptance and Action Scale (VAAS) Scores(3 weeks (baseline to follow-up))
- Change in Electroencephalography (EEG) - Resting-State Gamma Power(3 weeks (baseline to follow-up))
- Change in Brain Magnetic Resonance Spectroscopy (MRS)(3 weeks (baseline to follow-up))
- Change in Electroencephalography (EEG) - Resting-State Beta Power(3 weeks (baseline to follow-up))
- Change in Electroencephalography (EEG) - P50(3 weeks (baseline to follow-up))
- Change in Brain Functional Magnetic Resonance Imaging (fMRI) - Resting-State(3 weeks (baseline to follow-up))
- Change in Brain Functional Magnetic Resonance Imaging (fMRI) - Mismatch Negativity (tonal)(3 weeks (baseline to follow-up))
- Change in Electroencephalography (EEG) - Resting-State Delta Power(3 weeks (baseline to follow-up))