Schizo Affective Disorder, Schizophrenia
Conditions
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.
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.
Interventions
DEVICEtDCS
active anodal tDCS and sham tDCS
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 about one week apart.
Eligibility
Sex/Gender
ALL
Age
18 Years to 64 Years
Healthy volunteers
No
Inclusion criteria
* Age = 18-64 * Diagnosed with schizophrenia or schizoaffective disorder * Having current (in the past week) or recent (in the past month) paranoia
Exclusion criteria
* Presence or history of a pervasive developmental disorder or mental retardation as defined by IQ \< 70 * Presence or history of neurological or medical disorders that contraindicate neural stimulation (e.g. presence or history of epilepsy, seizures, etc.) * Demonstrating sensory limitations, including uncorrectable visual or hearing impairments that interfere with assessment * History of electroconvulsive therapy * Lack of proficiency in English * Substance use disorder not in remission in the past 6 months * Any implanted devices such as pace maker, neurostimulator * Pregnancy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Ecological Momentary Assessment (EMA)-Based Social Functioning | Change in daily interactions was 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 was measured by Ecological Momentary Assessment (EMA) (i.e., questions about daily interactions with others). Two subscores were generated: social interaction frequency (score ranges from 0-5, a higher score indicates more frequent social interactions), social interaction motivation and experience (scores range from 1-7, a higher score indicates higher motivations to interact with others and better experiences during these interactions). |
| The State Social Paranoia Scale (SSPS) | The assessment was completed before the stimulation and 30 minutes after completion of the active/sham stimulation | Paranoid ideation was measured by the State Social Paranoia Scale (SSPS). Participants indicated 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. |
| Ecological Momentary Assessment (EMA)-Based Paranoia | Change in daily paranoia feelings was 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 was measured by Ecological Momentary Assessment (EMA), which involved questions about feelings of paranoia in daily life. The paranoia-related question is as follows: Since the past alarm, how much have you had thoughts that you really can't trust other people? The score for this item ranges from 1 to 7, with a higher score indicating a higher level of paranoid thinking. |
| Birchwood Social Functioning Scale (SFS) | The assessment was completed 30 minutes after completion of the active/sham stimulation | Social functioning was 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). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| The Trustworthiness Task | The assessment was completed 30 minutes after completion of the active/sham stimulation | Paranoid ideation was measured by the Trustworthiness Task. This task requires participants to indicate how much they trust each of 60 grayscale facial stimuli along a 7-point Likert scale (-3 = very untrustworthy, 3 = very trustworthy). Total scores were calculated by averaging across responses and hence varied from -3 to +3, with higher values indicating a greater tendency to trust others. |
| The Scrambled-sentences Task (SST) | The assessment was completed 30 minutes after completion of the active/sham stimulation | Paranoid ideation was measured by the Scrambled-sentences task (SST). This task measures the level of paranoia by asking participants to create sentences of either paranoid or nonparanoid meanings, with a greater percentage indicating a higher level of paranoid interpretation bias (range = 0-1). |
| The Ambiguous Intentions Hostility Questionnaire (AIHQ) | The assessment was completed 30 minutes after completion of the active/sham stimulation | Paranoid ideation was measured by the Ambiguous Intentions Hostility Questionnaire (AIHQ). Three subscores were generated: AIHQ (blame) (ranging from 3-16, with a higher score indicating a higher level of blaming tendency), AIHQ (hostility) (ranging from 1-5, with a higher score indicating a higher level of hostility), AIHQ (aggression) (ranging from 1-5, with a higher score indicating a higher level of aggression). |
| The Hostility Scale of the Personality Inventory for DSM-5 (PID-5-HS) | The assessment was completed 30 minutes after completion of the active/sham stimulation | Paranoid ideation was measured by the Hostility Scale of the Personality Inventory for DSM-5 (PID-5-HS). PID-5-HS contains 10 self-report items assessing pathological hostility. A total score (range from 0-30) was generated to reflect overall hostility level, with higher total scores indicating more hostility. |
Countries
United States
Participant flow
Recruitment details
A total of 50 participants were enrolled and eventually completing the whole procedure.
Participants by arm
| Arm | Count |
|---|---|
| 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.
tDCS: active anodal tDCS and sham tDCS | 26 |
| 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.
tDCS: active anodal tDCS and sham tDCS | 24 |
| Total | 50 |
Baseline characteristics
| Characteristic | Sham tDCS First, Then Active Anodal tDCS | Total | Active Anodal tDCS First, Then Sham tDCS |
|---|---|---|---|
| Age, Continuous | 45.46 years STANDARD_DEVIATION 11.3 | 44.74 years STANDARD_DEVIATION 10.67 | 44.08 years STANDARD_DEVIATION 10.24 |
| Chlorpromazine (CPZ)-equivalent | 396.32 mg STANDARD_DEVIATION 520.71 | 433.92 mg STANDARD_DEVIATION 896.59 | 468.63 mg STANDARD_DEVIATION 1150.45 |
| Current/recent paranoia Current | 17 participants | 38 participants | 21 participants |
| Current/recent paranoia Recent | 7 participants | 12 participants | 5 participants |
| Diagnoses SCZ | 13 participants | 21 participants | 8 participants |
| Diagnoses SCZ-A | 11 participants | 29 participants | 18 participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 23 Participants | 46 Participants | 23 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 1 Participants | 4 Participants | 3 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Handedness left-handed | 2 participants | 5 participants | 3 participants |
| Handedness right-handed | 22 participants | 45 participants | 23 participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 1 Participants | 3 Participants | 2 Participants |
| Race (NIH/OMB) Black or African American | 13 Participants | 27 Participants | 14 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 | 1 Participants | 2 Participants | 1 Participants |
| Race (NIH/OMB) White | 9 Participants | 18 Participants | 9 Participants |
| Region of Enrollment United States | 24 participants | 50 participants | 26 participants |
| Sex: Female, Male Female | 12 Participants | 26 Participants | 14 Participants |
| Sex: Female, Male Male | 12 Participants | 24 Participants | 12 Participants |
| The Wide Range Achievement Test-Reading recognition subtest 4 (WRAT-4) | 94.08 units on a scale STANDARD_DEVIATION 15.02 | 95.14 units on a scale STANDARD_DEVIATION 12.47 | 96.11 units on a scale STANDARD_DEVIATION 9.76 |
| Years of education | 13.31 years STANDARD_DEVIATION 2.26 | 12.85 years STANDARD_DEVIATION 2.2 | 12.42 years STANDARD_DEVIATION 2.08 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 50 | 0 / 50 |
| other Total, other adverse events | 0 / 50 | 0 / 50 |
| serious Total, serious adverse events | 0 / 50 | 0 / 50 |
Outcome results
Primary
Birchwood Social Functioning Scale (SFS)
Social functioning was 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).
Time frame: The assessment was completed 30 minutes after completion of the active/sham stimulation
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Visit | Birchwood Social Functioning Scale (SFS) | 114.21 units on a scale | Standard Deviation 22.35 |
| Sham Visit | Birchwood Social Functioning Scale (SFS) | 114.59 units on a scale | Standard Deviation 27.54 |
p-value: 0.98t-test, 2 sided
Primary
Ecological Momentary Assessment (EMA)-Based Paranoia
Paranoid ideation was measured by Ecological Momentary Assessment (EMA), which involved questions about feelings of paranoia in daily life. The paranoia-related question is as follows: Since the past alarm, how much have you had thoughts that you really can't trust other people? The score for this item ranges from 1 to 7, with a higher score indicating a higher level of paranoid thinking.
Time frame: Change in daily paranoia feelings was 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)
Population: Only 47 (out of 50) participants completed this measure.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Visit | Ecological Momentary Assessment (EMA)-Based Paranoia | 3.78 units on a scale | Standard Deviation 1.72 |
| Sham Visit | Ecological Momentary Assessment (EMA)-Based Paranoia | 3.61 units on a scale | Standard Deviation 0.91 |
| EMA-sham | Ecological Momentary Assessment (EMA)-Based Paranoia | 3.96 units on a scale | Standard Deviation 1.85 |
p-value: 0.042Multilevel Modeling
Primary
Ecological Momentary Assessment (EMA)-Based Social Functioning
Social functioning was measured by Ecological Momentary Assessment (EMA) (i.e., questions about daily interactions with others). Two subscores were generated: social interaction frequency (score ranges from 0-5, a higher score indicates more frequent social interactions), social interaction motivation and experience (scores range from 1-7, a higher score indicates higher motivations to interact with others and better experiences during these interactions).
Time frame: Change in daily interactions was 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)
Population: Only 47 (out of 50) participants completed this measure.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Active Visit | Ecological Momentary Assessment (EMA)-Based Social Functioning | Social interaction frequency | 0.97 score on a scale | Standard Deviation 0.76 |
| Active Visit | Ecological Momentary Assessment (EMA)-Based Social Functioning | Social interaction motivation and experience | 3.74 score on a scale | Standard Deviation 1.62 |
| Sham Visit | Ecological Momentary Assessment (EMA)-Based Social Functioning | Social interaction frequency | 0.91 score on a scale | Standard Deviation 0.83 |
| Sham Visit | Ecological Momentary Assessment (EMA)-Based Social Functioning | Social interaction motivation and experience | 4.08 score on a scale | Standard Deviation 1.68 |
| EMA-sham | Ecological Momentary Assessment (EMA)-Based Social Functioning | Social interaction frequency | 0.92 score on a scale | Standard Deviation 0.9 |
| EMA-sham | Ecological Momentary Assessment (EMA)-Based Social Functioning | Social interaction motivation and experience | 3.71 score on a scale | Standard Deviation 1.62 |
p-value: 0.01Multilevel Modeling
Primary
The State Social Paranoia Scale (SSPS)
Paranoid ideation was measured by the State Social Paranoia Scale (SSPS). Participants indicated 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.
Time frame: The assessment was completed before the stimulation and 30 minutes after completion of the active/sham stimulation
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Visit | The State Social Paranoia Scale (SSPS) | 9.72 The change score of SSPS (pre - post) | Standard Deviation 14.61 |
| Sham Visit | The State Social Paranoia Scale (SSPS) | 3.90 The change score of SSPS (pre - post) | Standard Deviation 11.56 |
p-value: 0.023ANOVA
Secondary
The Ambiguous Intentions Hostility Questionnaire (AIHQ)
Paranoid ideation was measured by the Ambiguous Intentions Hostility Questionnaire (AIHQ). Three subscores were generated: AIHQ (blame) (ranging from 3-16, with a higher score indicating a higher level of blaming tendency), AIHQ (hostility) (ranging from 1-5, with a higher score indicating a higher level of hostility), AIHQ (aggression) (ranging from 1-5, with a higher score indicating a higher level of aggression).
Time frame: The assessment was completed 30 minutes after completion of the active/sham stimulation
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Active Visit | The Ambiguous Intentions Hostility Questionnaire (AIHQ) | AIHQ (blame) | 8.28 score on a scale | Standard Deviation 3.07 |
| Active Visit | The Ambiguous Intentions Hostility Questionnaire (AIHQ) | AIHQ (hostility) | 2.09 score on a scale | Standard Deviation 0.75 |
| Active Visit | The Ambiguous Intentions Hostility Questionnaire (AIHQ) | AIHQ (aggression) | 1.75 score on a scale | Standard Deviation 0.4 |
| Sham Visit | The Ambiguous Intentions Hostility Questionnaire (AIHQ) | AIHQ (blame) | 8.89 score on a scale | Standard Deviation 3.22 |
| Sham Visit | The Ambiguous Intentions Hostility Questionnaire (AIHQ) | AIHQ (hostility) | 2.35 score on a scale | Standard Deviation 0.78 |
| Sham Visit | The Ambiguous Intentions Hostility Questionnaire (AIHQ) | AIHQ (aggression) | 1.78 score on a scale | Standard Deviation 0.39 |
p-value: 0.041t-test, 2 sided
Secondary
The Hostility Scale of the Personality Inventory for DSM-5 (PID-5-HS)
Paranoid ideation was measured by the Hostility Scale of the Personality Inventory for DSM-5 (PID-5-HS). PID-5-HS contains 10 self-report items assessing pathological hostility. A total score (range from 0-30) was generated to reflect overall hostility level, with higher total scores indicating more hostility.
Time frame: The assessment was completed 30 minutes after completion of the active/sham stimulation
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Visit | The Hostility Scale of the Personality Inventory for DSM-5 (PID-5-HS) | 9.42 score on a scale | Standard Deviation 7.56 |
| Sham Visit | The Hostility Scale of the Personality Inventory for DSM-5 (PID-5-HS) | 11.30 score on a scale | Standard Deviation 7.57 |
p-value: 0.019t-test, 2 sided
Secondary
The Scrambled-sentences Task (SST)
Paranoid ideation was measured by the Scrambled-sentences task (SST). This task measures the level of paranoia by asking participants to create sentences of either paranoid or nonparanoid meanings, with a greater percentage indicating a higher level of paranoid interpretation bias (range = 0-1).
Time frame: The assessment was completed 30 minutes after completion of the active/sham stimulation
Population: Only 49 (out of 50) participants completed this task.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Visit | The Scrambled-sentences Task (SST) | 0.46 score on a scale | Standard Deviation 0.29 |
| Sham Visit | The Scrambled-sentences Task (SST) | 0.49 score on a scale | Standard Deviation 0.28 |
p-value: 0.306t-test, 2 sided
Secondary
The Trustworthiness Task
Paranoid ideation was measured by the Trustworthiness Task. This task requires participants to indicate how much they trust each of 60 grayscale facial stimuli along a 7-point Likert scale (-3 = very untrustworthy, 3 = very trustworthy). Total scores were calculated by averaging across responses and hence varied from -3 to +3, with higher values indicating a greater tendency to trust others.
Time frame: The assessment was completed 30 minutes after completion of the active/sham stimulation
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Visit | The Trustworthiness Task | 0.07 score on a scale | Standard Deviation 1.16 |
| Sham Visit | The Trustworthiness Task | -0.18 score on a scale | Standard Deviation 0.99 |
p-value: 0.064t-test, 2 sided