Stimulating the Brain to Improve Self-Awareness

Study Overview
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Brief Summary
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This study investigates whether Introspective Accuracy (IA) can be improved in individuals with schizophrenia by stimulating the brain via transcranial Direct Current Stimulation (tDCS).

Detailed Description
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Self-awareness is markedly impaired in severe mental illness including schizophrenia and schizoaffective disorder. This impairment spans awareness of symptoms as well as deficits in the estimation of abilities and capabilities, which we refer to as introspective accuracy (IA). Recent work has provided evidence of IA deficits in schizophrenia spectrum disorders, specifically in the abilities to retrospectively judge everyday functioning and neurocognitive impairment, as well as the ability to make correct real-time judgments of performance on neurocognitive tests. Transcranial Direct Current Stimulation (tDCS) is a form of noninvasive neurostimulation which has been proposed as a therapeutic procedure in numerous psychiatric disorders. TDCS in healthy adults has been demonstrated to improve cognitive and memory performance, and in schizophrenia, tDCS has been found to improve emotion recognition ability. TDCS thus appears to be a promising therapeutic technique that may be useful for improving IA. This study will compare IA performance in individuals with schizophrenia across two conditions: active anodal tDCS and sham tDCS.

Official Title
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Stimulating the Brain to Improve Self-Awareness

Conditions
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Schizophrenia, Schizoaffective Disorder

Intervention / Treatment
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* Device: active anodal tDCS
* Device: sham tDCS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age: 18-55 DSM-IV-TR or DSM-5 diagnosis of schizophrenia or schizoaffective disorder and clinically stable (i.e., no hospitalizations) for at least 8 weeks and on a stable medication regimen for at least 6 weeks with no dose changes for a minimum of 2 weeks Exclusion Criteria: Presence or history of pervasive developmental disorder (e.g., autism) or mental retardation (defined as IQ <70) by DSM-IV criteria Presence or history of medical, cardiac, or neurological disorders that may affect brain function (e.g., cardiac disease, endocrine disorders, renal disease, pulmonary disease, history of seizures or head trauma with unconsciousness for a period of 15 minutes or greater or CNS tumors) Presence of sensory limitation including visual (e.g., blindness, glaucoma, vision uncorrectable to 20/40) or hearing (e.g. hearing loss) impairments that interfere with assessment Not proficient in English Presence of substance abuse in the past one month Presence of substance dependence not in remission for the past six months Contraindications for tDCS (e.g., pregnancy or implanted devices such as pace maker)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Participants will complete active and sham simulation sessions in a randomized, counterbalanced order approximately one week apart.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Active anodal tDCS first, then Sham tDCS<br>Active anodal tDCS (20 minutes) followed by behavioral testing; Washout (1 week); sham stimulation (20 minutes) followed by behavioral testing Intervention: Device: active anodal tDCS and sham tDCS | Device: active anodal tDCS<br>* active anodal tDCS with behavioral tasks to assess IA<br>Device: sham tDCS<br>* sham tDCS with behavioral tasks to assess IA<br>|
| Sham Comparator: Sham tDCS first, then Active anodal tDCS<br>Sham tDCS (20 minutes) followed by behavioral testing; Washout (1 week); Active anodal tDCS (20 minutes) followed by behavioral testing Intervention: Device: sham tDCS and sham tDCS | Device: active anodal tDCS<br>* active anodal tDCS with behavioral tasks to assess IA<br>Device: sham tDCS<br>* sham tDCS with behavioral tasks to assess IA<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Neurocognitive Introspective Accuracy for Active vs. Sham Stimulation | Neurocognitive Introspective Accuracy (IA) was assessed with the Wisconsin Card Sorting Task after both Active and Sham stimulation. The area under a type 2 ROC (receiver operating characteristic) curve was used to index IA. Values range from .5-1, with higher values indicating better IA. | Assessment will be completed 30 minutes after completion of the active/sham stimulation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Social Cognitive Introspective Accuracy for Active vs. Sham Stimulation | Social Cognitive Introspective Accuracy assessed with the Penn Emotion Recognition Task (ER40) after both Active and Sham stimulation. The area under a type 2 ROC (receiver operating characteristic) curve was used to index IA. Values range from .5-1, with higher values indicating better IA. | Assessment will be completed 30 minutes after completion of the active/sham stimulation |