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This study investigates whether the way in which individuals process social stimuli can be altered, and specifically, whether feelings of paranoia and suspiciousness can be reduced by stimulating the brain's regulatory regions via transcranial Direct Current Stimulation (tDCS).
Although paranoid ideation is typically associated with severe mental illnesses such as schizophrenia or bipolar disorder, 10-15% of individuals in the general population report experiencing paranoid thoughts on a regular basis. These individuals who are high in sub-clinical paranoia can show impaired work and social functioning as compared to individuals low in sub-clinical paranoia. The wide spread prevalence and negative functional impact of heightened paranoia reinforces the need to develop interventions that may help to reduce problematic patterns of paranoid thinking in both healthy individuals and those with mental illness.
Transcranial Direct Current Stimulation (tDCS) is a form of noninvasive neurostimulation which has been proposed as a therapeutic procedure in numerous psychiatric conditions. TDCS therefore may be a promising therapeutic technique for reducing symptoms of psychosis, and specifically paranoia. This study will compare experiences of paranoid ideation in individuals who are high in sub-clinical paranoia across two conditions: active anodal tDCS and sham tDCS.
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Active anodal tDCS, Then Sham tDCS | Experimental | Active anodal tDCS followed by behavioral testing; one week later, sham tDCS followed by behavioral testing |
|
| Sham tDCS, then Active anodal tDCS | Sham Comparator | Sham tDCS followed by behavioral testing; one week later, active anodal tDCS followed by behavioral testing. |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| active anodal tDCS | Device | active anodal tDCS with behavioral tasks and self-report measures to assess paranoid ideation |
|
| Measure | Description | Time Frame |
|---|---|---|
| Change in General Paranoid Ideation for Active vs. Sham Simulation | Level of paranoid ideation will be assessed with the self-report Paranoia Scale (PS; Fenigstein & Vanable, 1992) both before and after tDCS to assess changes related to tDCS. The PS is a self-report measure designed to assess sub-clinical paranoid thought. Scores range from 20-100 with higher scores indicating higher levels of paranoia. The amount of pre-post change (i.e. PS score assessed before stimulation minus score after stimulation) is the primary value of interest and will be compared between active and sham stimulation. Improvements in paranoia will be indicated by positive values. | Paranoid ideation will be assessed 30 minutes after completion of the active/sham stimulation |
| Change in Change in Social Paranoia for Active vs. Sham Simulation | Level of paranoid ideation will be assessed with the persecution subscale of the State Social Paranoia Scale (SSPS: Freeman et al., 2007) both before and after tDCS to assess changes related to tDCS. The SSPS is a psychometrically sound 20-item self- report measure assessing current levels of paranoid, positive, and neutral thinking about others. Ten items comprise the persecution subscale, and scores on this subscale range from 10-50 with higher scores indicating greater paranoia. The amount of pre-post change (i.e.SSPS score before stimulation minus SSPS score after stimulation) will be compared between active and sham stimulation. Positive values indicate reductions in paranoia after stimulation. | Paranoid ideation will be assessed 30 minutes after completion of the active/sham stimulation |
| Measure | Description | Time Frame |
|---|---|---|
| Trustworthiness Task Score for Active vs. Sham Stimulation | Participants will complete the Trustworthiness Task (Adolphs, Tranel, & Damasio, 1998), which asks individuals to view 42 images of others and rate their level of trustworthiness on a scale from -3 to 3. Scores range from -126 to 126. Higher scores indicate greater perceptions of trustworthiness. Mean ratings following each stimulation type (active vs. sham) are calculated. |
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Inclusion Criteria:
Exclusion Criteria:
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| Name | Affiliation | Role |
|---|---|---|
| Amy Pinkham, PhD | The University of Texas at Dallas | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| The Unversity of Texas at Dallas | Richardson | Texas | 75080 | United States |
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| ID | Title | Description |
|---|---|---|
| FG000 | Active Anodal tDCS, Then Sham tDCS | Active anodal tDCS followed by behavioral testing; one week later, sham tDCS followed by behavioral testing active anodal tDCS: active anodal tDCS with behavioral tasks and self-report measures to assess paranoid ideation sham tDCS: sham tDCS with behavioral tasks and self-report measures to assess paranoid ideation |
| FG001 | Sham tDCS, Then Active Anodal tDCS | Sham tDCS followed by behavioral testing; one week later, active anodal tDCS followed by behavioral testing. active anodal tDCS: active anodal tDCS with behavioral tasks and self-report measures to assess paranoid ideation sham tDCS: sham tDCS with behavioral tasks and self-report measures to assess paranoid ideation |
| Title | Milestones | Reasons Not Completed | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| First Intervention (20 Minutes) |
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| Washout (1 Week) |
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| Second Intervention (20 Minutes) |
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| ID | Title | Description |
|---|---|---|
| BG000 | Active Anodal tDCS, Then Sham tDCS | Active anodal tDCS followed by behavioral testing; one week later, sham tDCS followed by behavioral testing active anodal tDCS: active anodal tDCS with behavioral tasks and self-report measures to assess paranoid ideation sham tDCS: sham tDCS with behavioral tasks and self-report measures to assess paranoid ideation |
| Units | Counts |
|---|---|
| Participants |
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| Title | Description | Population Description | Parameter Type | Dispersion Type | Unit of Measure | Calculate Percentage | Denominator Units Selected | Denominators | Classes |
|---|---|---|---|---|---|---|---|---|---|
| Age, Continuous | Mean |
| Type | Title | Description | Population Description | Reporting Status | Anticipated Posting Date | Parameter Type | Dispersion Type | Unit of Measure | Calculate Percentage | Time Frame | Units Analyzed | Denominator Units Selected | Arm/Group Information | Denominators | Classes | Analyses | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Primary | Change in General Paranoid Ideation for Active vs. Sham Simulation | Level of paranoid ideation will be assessed with the self-report Paranoia Scale (PS; Fenigstein & Vanable, 1992) both before and after tDCS to assess changes related to tDCS. The PS is a self-report measure designed to assess sub-clinical paranoid thought. Scores range from 20-100 with higher scores indicating higher levels of paranoia. The amount of pre-post change (i.e. PS score assessed before stimulation minus score after stimulation) is the primary value of interest and will be compared between active and sham stimulation. Improvements in paranoia will be indicated by positive values. | Posted | Mean | Standard Deviation | score on a scale | Paranoid ideation will be assessed 30 minutes after completion of the active/sham stimulation |
|
10 days for each arm.
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| ID | Title | Description | Deaths (Affected) | Deaths (At Risk) | Serious Events (Affected) | Serious Events (At Risk) | Other Events (Affected) | Other Events (At Risk) |
|---|---|---|---|---|---|---|---|---|
| EG000 | Active Anodal tDCS | 20 minutes of Active anodal tDCS followed by behavioral testing |
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| Title | Organization | Phone | Extension | |
|---|---|---|---|---|
| Dr. Amy Pinkham | The University of Texas at Dallas | (972) 883-4462 | amy.pinkham@utdallas.edu |
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| Type | Includes Protocol | Includes SAP | Includes ICF | Document Label | Document Date | Document Uploaded Date | Document File Name |
|---|---|---|---|---|---|---|---|
| Prot_SAP | Yes | Yes | No | Study Protocol and Statistical Analysis Plan | Oct 2, 2017 | Mar 23, 2022 | Prot_SAP_000.pdf |
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Participants will complete active and sham simulation sessions in a randomized, counterbalanced order approximately one week apart.
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| sham tDCS | Device | sham tDCS with behavioral tasks and self-report measures to assess paranoid ideation |
|
| assessed 30 minutes after completion of the active/sham stimulation |
| Penn Emotion Recognition Test for Active vs. Sham Stimulation | The Emotion Recognition 40 (ER-40; Kohler, Turner, Bilker, Brinsinger, Siegel, Kanes... Gur, 2003) is a standardized, computer administered measure of facial affect recognition ability. It includes 40 color photographs of faces expressing 4 basic emotions (i.e. happiness, sadness, anger or fear) and neutral expressions. Participants view one face at a time and are asked to choose the correct emotion for each face. Scores range from 0-40 with higher scores indicating better accuracy. Mean performance following each stimulation type (active vs. sham) are calculated. | assessed 30 minutes after completion of the active/sham stimulation |
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| BG001 |
| Sham tDCS, Then Active Anodal tDCS |
Sham tDCS followed by behavioral testing; one week later, active anodal tDCS followed by behavioral testing. active anodal tDCS: active anodal tDCS with behavioral tasks and self-report measures to assess paranoid ideation sham tDCS: sham tDCS with behavioral tasks and self-report measures to assess paranoid ideation |
| BG002 | Total | Total of all reporting groups |
| years |
|
| Sex: Female, Male | Count of Participants | Participants |
|
| Ethnicity (NIH/OMB) | Count of Participants | Participants |
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| Race (NIH/OMB) | Count of Participants | Participants |
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| Region of Enrollment | Number | participants |
|
| OG001 | Sham Stimulation | 20 minutes of Sham tDCS followed by behavioral testing |
|
|
| Primary | Change in Change in Social Paranoia for Active vs. Sham Simulation | Level of paranoid ideation will be assessed with the persecution subscale of the State Social Paranoia Scale (SSPS: Freeman et al., 2007) both before and after tDCS to assess changes related to tDCS. The SSPS is a psychometrically sound 20-item self- report measure assessing current levels of paranoid, positive, and neutral thinking about others. Ten items comprise the persecution subscale, and scores on this subscale range from 10-50 with higher scores indicating greater paranoia. The amount of pre-post change (i.e.SSPS score before stimulation minus SSPS score after stimulation) will be compared between active and sham stimulation. Positive values indicate reductions in paranoia after stimulation. | Posted | Mean | Standard Deviation | score on a scale | Paranoid ideation will be assessed 30 minutes after completion of the active/sham stimulation |
|
|
|
| Secondary | Trustworthiness Task Score for Active vs. Sham Stimulation | Participants will complete the Trustworthiness Task (Adolphs, Tranel, & Damasio, 1998), which asks individuals to view 42 images of others and rate their level of trustworthiness on a scale from -3 to 3. Scores range from -126 to 126. Higher scores indicate greater perceptions of trustworthiness. Mean ratings following each stimulation type (active vs. sham) are calculated. | Posted | Mean | Standard Deviation | score on a scale | assessed 30 minutes after completion of the active/sham stimulation |
|
|
|
| Secondary | Penn Emotion Recognition Test for Active vs. Sham Stimulation | The Emotion Recognition 40 (ER-40; Kohler, Turner, Bilker, Brinsinger, Siegel, Kanes... Gur, 2003) is a standardized, computer administered measure of facial affect recognition ability. It includes 40 color photographs of faces expressing 4 basic emotions (i.e. happiness, sadness, anger or fear) and neutral expressions. Participants view one face at a time and are asked to choose the correct emotion for each face. Scores range from 0-40 with higher scores indicating better accuracy. Mean performance following each stimulation type (active vs. sham) are calculated. | Posted | Mean | Standard Deviation | score on a scale | assessed 30 minutes after completion of the active/sham stimulation |
|
|
|
| 0 |
| 40 |
| 0 |
| 40 |
| 0 |
| 40 |
| EG001 | Sham tDCS | 20 minutes of Sham tDCS followed by behavioral testing | 0 | 40 | 0 | 40 | 0 | 40 |
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