The Efficacy of Neural Stimulation in Individuals With Schizophrenia
Study Details
Study Description
Brief Summary
The purpose of this study is to understand the relationship between psychotic symptoms and social functioning in individuals with schizophrenia spectrum disorders. Our goal is to determine whether stimulating the brain using transcranial Direct Current Stimulation (tDCS) can improve symptoms and daily functioning.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
Detailed Description
Paranoid ideation is a common delusion experienced by individuals with schizophrenia spectrum disorders (SSD) that negatively impacts social interactions and quality of life. Therefore, efforts to reduce paranoid thinking via neuromodulation techniques [e.g., transcranial direct current stimulation (tDCS)] are in development, with amygdala-prefrontal cortex (PFC) circuits targeted as critical components of the neural mechanisms underlying paranoia.
This project aims to alleviate paranoia and improve social functioning in individuals with SSD by implementing tDCS to ventrolateral PFC. A double-blind, within-subjects, crossover design will be used to compare the effects of active vs. sham tDCS. Ecological Momentary Assessments (EMA) will also be utilized to quantify any delayed stimulation effects in daily social interactions.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Active anodal tDCS first, then Sham tDCS Active anodal tDCS (40 minutes; divided into two 20-minutes sessions) followed by behavioral testing; Washout (about 1 week); sham stimulation (40 minutes; divided into two 20-minutes sessions) followed by behavioral testing. |
Device: tDCS
active anodal tDCS and sham tDCS
|
| Sham Comparator: Sham tDCS first, then Active anodal tDCS Sham tDCS (40 minutes; divided into two 20-minutes sessions) followed by behavioral testing; Washout (about 1 week); Active anodal tDCS (40 minutes; divided into two 20-minutes sessions) followed by behavioral testing Intervention. |
Device: tDCS
active anodal tDCS and sham tDCS
|
Outcome Measures
Primary Outcome Measures
- Paranoid Ideation for Active vs. Sham Stimulation [The assessment will be completed 30 minutes after completion of the active/sham stimulation]
Paranoid ideation will be measured by the State Social Paranoia Scale (SSPS). Participants will indicate how much they agree with each of 20 statements (e.g., "Someone was hostile towards me", "Someone was trying to isolate me") using a 5-point Likert scale (1 = do not agree, 5 = totally agree). Scores range from 20-100, and higher scores represent higher state paranoid ideation.
- Paranoid Ideation for Active vs. Sham Stimulation [The assessment will be completed 30 minutes after completion of the active/sham stimulation]
Paranoid ideation will be measured by the Hostility Scale of the Personality Inventory for DSM-5 (PID-5-HS). PID-5-HS contains 10 self-report items (e.g., "I snap at people when they do little things that irritate me") assessing pathological hostility on a 4-point scale (0 = very false or often false, 3 = very true or often true), with higher total scores indicating more hostility (range = 0-30).
- Paranoid Ideation for Active vs. Sham Stimulation [The assessment will be completed 30 minutes after completion of the active/sham stimulation]
Paranoid ideation will be measured by the Ambiguous Intentions Hostility Questionnaire (AIHQ). Five ambiguous scenarios will be presented to participants, and they will be asked to give reasons why each situation happened, indicate how much they think that people did this to them on purpose, how angry they are, how much they will blame others, and what they will do about it. Responses will be recorded verbatim or based on 6-point (if the behavior is on purpose) and 5-point (how angry they are, how much they will blame others) Likert scales. For the open-ended questions, hostility and aggression biases will be rated by three independent, trained raters using a 5-point Likert scale (1 = not hostile/aggressive at all, 5 = very hostile/aggressive). Inter-rater reliability will be computed by ICC among all the raters, with ICC > .80 being acceptable.
- Paranoid Ideation for Active vs. Sham Stimulation [The assessment will be completed 30 minutes after completion of the active/sham stimulation]
Paranoid ideation will be measured by the Scrambled-sentences task (SST)
- Paranoid Ideation for Active vs. Sham Stimulation [The assessment will be completed 30 minutes after completion of the active/sham stimulation]
Paranoid ideation will be measured by the Trustworthiness Task
- Paranoid Ideation for Active vs. Sham Stimulation [Change in daily paranoia feelings will be assessed from the pre-stimulation EMA period (7 days before the stimulation visit) to the post-stimulation EMA period (7 days after the stimulation visit)]
Paranoid ideation will be measured by EMA (i.e., questions about feelings of paranoia in daily life).
- Social functioning for Active vs. Sham Stimulation [The assessment will be completed 30 minutes after completion of the active/sham stimulation]
Social functioning will be measured by the Birchwood Social Functioning Scale (SFS). This scale measures social adjustment based on self-reports (4- or 5-point scales), with higher total scores indicating better social functioning (range = 0-223).
- Social functioning for Active vs. Sham Stimulation [Change in daily interactions will be assessed from the pre-stimulation EMA period (7 days before the stimulation visit) to the post-stimulation EMA period (7 days after the stimulation visit)]
Social functioning will be measured by EMA (i.e., questions about daily interactions with others)
- Social functioning for Active vs. Sham Stimulation [Change in daily experience in social interactions will be assessed from the pre-stimulation EMA period (7 days before the stimulation visit) to the post-stimulation EMA period (7 days after the stimulation visit)]
Social functioning will be measured by EMA (i.e., questions about daily experience in social interactions).
- Social functioning for Active vs. Sham Stimulation [Change in daily expectations of social interactions will be assessed from the pre-stimulation EMA period (7 days before the stimulation visit) to the post-stimulation EMA period (7 days after the stimulation visit)]
Social functioning will be measured by EMA (i.e., questions about daily expectations of social interactions).
Eligibility Criteria
Criteria
Inclusion Criteria:
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Age = 18-60
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Diagnosed with schizophrenia or schizoaffective disorder
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Having current (in the past week) or recent (in the past month) paranoia
Exclusion Criteria:
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Presence or history of a pervasive developmental disorder or mental retardation as defined by IQ < 70
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Presence or history of neurological or medical disorders that contraindicate neural stimulation (e.g. presence or history of epilepsy, seizures, etc.)
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Demonstrating sensory limitations, including uncorrectable visual or hearing impairments that interfere with assessment
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History of electroconvulsive therapy
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Lack of proficiency in English
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Substance use disorder not in remission in the past 6 months
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Any implanted devices such as pace maker, neurostimulator
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Pregnancy
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | The Unversity of Texas at Dallas | Richardson | Texas | United States | 75080 |
Sponsors and Collaborators
- The University of Texas at Dallas
Investigators
None specified.Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- 22-630