Schizoaffective Disorder, Schizophrenia
Conditions
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.
Interventions
DEVICEactive anodal tDCS
active anodal tDCS with behavioral tasks to assess IA
DEVICEsham tDCS
sham tDCS with behavioral tasks to assess IA
Sponsors
The University of Texas at Dallas
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Outcomes Assessor)
Intervention model description
Participants will complete active and sham simulation sessions in a randomized, counterbalanced order approximately one week apart.
Eligibility
Sex/Gender
ALL
Age
18 Years to 55 Years
Healthy volunteers
No
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)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Active Anodal tDCS First, Then Sham Stimulation Active anodal tDCS followed by behavioral testing; Washout (1 week); Sham tDCS followed by behavioral testing
Intervention: Device: active anodal tDCS | 21 |
| Sham tDCS First, Then Active Stimulation Sham tDCS followed by behavioral testing; Washout (1 week); Active tDCS followed by behavioral testing Intervention: Device: sham tDCS
sham tDCS: sham tDCS with behavioral tasks to assess IA | 20 |
| Total | 41 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Lost to Follow-up | 0 | 1 |
Baseline characteristics
| Characteristic | Active Anodal tDCS First, Then Sham Stimulation | Sham tDCS First, Then Active Stimulation | Total |
|---|---|---|---|
| Age, Continuous | 39.43 years STANDARD_DEVIATION 11.05 | 39.58 years STANDARD_DEVIATION 9.84 | 39.5 years STANDARD_DEVIATION 10.36 |
| Education | 12.33 years STANDARD_DEVIATION 2.81 | 12.34 years STANDARD_DEVIATION 1.93 | 12.34 years STANDARD_DEVIATION 2.41 |
| Estimated IQ | 98.95 units on a scale STANDARD_DEVIATION 11.57 | 94.26 units on a scale STANDARD_DEVIATION 10.01 | 96.73 units on a scale STANDARD_DEVIATION 10.98 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 6 Participants | 6 Participants | 12 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 15 Participants | 14 Participants | 29 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 7 Participants | 11 Participants | 18 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 14 Participants | 9 Participants | 23 Participants |
| Region of Enrollment United States | 21 participants | 20 participants | 41 participants |
| Sex: Female, Male Female | 11 Participants | 6 Participants | 17 Participants |
| Sex: Female, Male Male | 10 Participants | 14 Participants | 24 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 40 | 0 / 41 |
| other Total, other adverse events | 0 / 40 | 0 / 41 |
| serious Total, serious adverse events | 0 / 40 | 0 / 41 |
Outcome results
Primary
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.
Time frame: Assessment will be completed 30 minutes after completion of the active/sham stimulation
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Anodal tDCS | Neurocognitive Introspective Accuracy for Active vs. Sham Stimulation | .534 score on a scale | Standard Deviation 0.068 |
| Sham tDCS | Neurocognitive Introspective Accuracy for Active vs. Sham Stimulation | .526 score on a scale | Standard Deviation 0.085 |
Comparison: The null hypothesis was that of no difference in levels of IA between Active and Sham stimulation. A paired samples t-test was performed with a significance level of 0.05 (two-tailed).p-value: 0.56t-test, 2 sided
Secondary
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.
Time frame: Assessment will be completed 30 minutes after completion of the active/sham stimulation
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Anodal tDCS | Social Cognitive Introspective Accuracy for Active vs. Sham Stimulation | .575 score on a scale | Standard Deviation 0.095 |
| Sham tDCS | Social Cognitive Introspective Accuracy for Active vs. Sham Stimulation | .562 score on a scale | Standard Deviation 0.098 |
Comparison: The null hypothesis was that of no difference in levels of IA between Active and Sham stimulation. A paired samples t-test was performed with a significance level of 0.05 (two-tailed).p-value: 0.38t-test, 2 sided