Stimulating the Brain to Improve Self-Awareness

Not Applicable

Completed

Brief Summary: 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: 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.

Recruitment & Eligibility

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)

Arm && Interventions

Group	Intervention	Description
Active anodal tDCS first, then Sham tDCS	active anodal tDCS	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
Sham tDCS first, then Active anodal tDCS	active anodal tDCS	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
Active anodal tDCS first, then Sham tDCS	sham tDCS	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
Sham tDCS first, then Active anodal tDCS	sham tDCS	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

Primary Outcome Measures

Name	Time	Method
Neurocognitive Introspective Accuracy for Active vs. Sham Stimulation	Assessment will be completed 30 minutes after completion of the active/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.

Secondary Outcome Measures

Name	Time	Method
Social Cognitive Introspective Accuracy for Active vs. Sham Stimulation	Assessment will be completed 30 minutes after completion of the active/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.