Transcranial Direct Current Stimulation and Antisocial Behavior

The Effect of Transcranial Direct Current Stimulation of the Prefrontal Cortex on Antisocial Behavior

The main objective of this study is to investigate the causal relationship between prefrontal cortex activity and antisocial behavior, as well as risk factors for antisocial behavior. Specifically, this study tests the hypothesis that upregulating activity in the prefrontal cortex through a non-invasive form of brain stimulation, transcranial direct current stimulation (tDCS) will reduce antisocial and aggressive behavior. The effects of 3 days of anodal stimulation over the prefrontal cortex are assessed.

Study Overview

• Status: Active, not recruiting
• Conditions: Aggression
• Intervention / Treatment: Device: Sham transcranial direct current stimulation; Device: Transcranial direct current stimulation

• Study Type: Interventional
• Enrollment (Actual): 101
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Singapore
  • Singapore, Singapore, 639818
    • Nanyang Technological University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Above 18 (with parental consent) or above 21 (without parental consent)
• Able to understand the nature of the study and give informed consent

Exclusion Criteria:

• History of or active neurologic, cardiovascular, or psychiatric disease including anxiety disorders (e.g., PTSD, panic attacks, obsessive-compulsive disorder) and mood disorders (e.g., depression)
• Currently consuming anti-convulsant, anti-psychotic, or sedative/hypnotic medications
• Currently consuming anti-depressants
• History of seizures
• Metallic implants on scalp
• Participated in any other non-invasive brain stimulation study in the same day
• Ever had an adverse reaction to tDCS

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Anodal stimulation; Participants in the active stimulation group will undergo anodal transcranial direct current stimulation (tDCS). tDCS will be delivered by a battery-driven, constant-current stimulator connected to two saline-soaked surface sponge electrodes. An anodal electrode (25cm2) will be placed over the ventromedial prefrontal cortex and one cathodal electrode (35cm2) will be placed over the occipital cortex. Scalp electrodes will be positioned according to the 10-20 EEG international system. A current of 2mA will be applied for 20 minutes and the current will be ramped up and down over 30 seconds at the beginning and end of the stimulation period.	Device: Transcranial direct current stimulation; Non-invasive stimulation will be conducted using a tDCS device (StarStim, Neuroelectrics, Spain).
Sham Comparator: Sham stimulation; The sham tDCS condition will involve the same placement of the electrodes, current intensity, and ramp-up/down time as the active tDCS condition, but stimulation will only last for 30 seconds.	Device: Sham transcranial direct current stimulation; The same device will be used as in the active stimulation group, but stimulation will be terminated after 30 seconds.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Points in the Point Subtraction Aggression Paradigm after stimulation	The number of points earned on the lab task will be assessed.	Within 1 hour after the third consecutive active tDCS or sham session
Antisocial behavior inclinations after stimulation	This will be assessed using 5 hypothetical scenarios in which someone commits a criminal or antisocial act. Participants will respond to the likelihood that they would commit the act in the scenario according to a 10-point Likert scale. Responses are measured on a scale ranging from zero (no chance at all) to 10 (100% chance). A higher value reflects a greater intention to engage in the antisocial act.	Within 1 hour after the third consecutive active tDCS or sham session
Moral judgment ratings after stimulation	This will be assessed using 5 hypothetical scenarios in which someone commits a criminal or antisocial act. Participants will rate the moral wrongfulness of the act in the scenario on a scale from 0 (not at all) to 10 (very). A higher score reflects a greater perception of moral wrongfulness regarding the antisocial act.	Within 1 hour after the third consecutive active tDCS or sham session
Delay discounting rates after stimulation	Participants' responses to 5 questions indicating if they would prefer a smaller reward today or a larger reward in the specified number of days will be assessed. The delay discount rates (k) of monetary rewards will be calculated based on the responses to the 5 trials.	Within 1 hour after the third consecutive active tDCS or sham session
Helping behavior after stimulation	This will be assessed based on the number of easy and hard puzzles participants choose to assign to another participant in the study.	Within 1 hour after the third consecutive active tDCS or sham session
Antisocial behavior after stimulation	This will be assessed based on the participants' accurate reporting of the number of problems correctly solved in a task.	Within 1 hour after the third consecutive active tDCS or sham session

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of participants with adverse events	The number of participants reporting the experience of sensations resulting from tDCS will be recorded.	Within 1 hour after each of the 20-minute active tDCS or sham sessions

Collaborators and Investigators

• Sponsor: Nanyang Technological University

Study record dates

Study Major Dates

• Study Start (Actual): November 3, 2019
• Primary Completion (Actual): May 1, 2022
• Study Completion (Anticipated): December 31, 2023

Study Registration Dates

• First Submitted: December 17, 2019
• First Submitted That Met QC Criteria: December 17, 2019
• First Posted (Actual): December 19, 2019

Study Record Updates

• Last Update Posted (Actual): October 18, 2022
• Last Update Submitted That Met QC Criteria: October 17, 2022
• Last Verified: October 1, 2022

More Information

Terms related to this study

• Keywords: antisocial behavior; transcranial direct curren stimulation
• Additional Relevant MeSH Terms: Behavioral Symptoms; Mental Disorders; Personality Disorders; Aggression; Antisocial Personality Disorder
• Other Study ID Numbers: IRB-2019-06-072

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No