Modulating Impulsivity in Suicidal Adolescents With Transcranial Direct Current Stimulation (tDCS)
Condition: Impulsive Behavior
MeSH terms: Impulsive Behavior
Study type: Interventional

Summary: 
      As a first step toward investigating whether modulation of impulsivity and associated neural
      pathways may yield clinically meaningful changes in risk for adolescent suicidal behavior,
      the R21 is a proof-of concept study evaluating the potential for tDCS targeting brain regions
      associated with behavioral impulsivity (right inferior frontal gyrus [rIFG]) and cognitive
      impulsivity (left orbitofrontal cortex [lOFC]) to modulate these facets of impulsivity in a
      sample of adolescent suicide attempters. Participants will be randomly assigned to receive
      anodal tDCS over the rIFG, anodal tDCS over the lOFC, or a sham stimulation condition, in a
      three-group design. Task-based measures of behavioral and cognitive impulsivity will be
      administered before and after tDCS or sham stimulation. Additionally, electroencephalography
      (EEG) and event-related potential (ERP) data will be collected during the impulsivity tasks,
      and resting-state EEG data will be collected pre- and post-tDCS administration to confirm
      engagement of the targeted brain regions and to delineating the neural pathways underlying
      the effects of tDCS on impulsivity.
    

Detailed description: 
      Suicide is one of the leading causes of death in adolescence. To improve the ability to
      predict and prevent suicidal behavior, there is a pressing need for research in this area to
      advance beyond identifying risk factors toward a greater focus on the mechanisms of risk for
      this behavior. In particular, elucidating the neural pathways underlying risk for suicidal
      behavior is important insofar as such work may yield specific and modifiable targets for
      clinical intervention. The adoption of new experimental paradigms providing experimental
      control over potentially modifiable risk factors has been recommended as a means of
      meaningfully advancing the field in this regard. Although yet to be applied to the study of
      suicidality, transcranial direct current stimulation (tDCS), in conjunction with measures of
      electroencephalography (EEG) and event-related potentials (ERPs), may hold promise as an
      experimental paradigm in the study of potentially modifiable risk factors, and underlying
      neural mechanisms, for suicidality. One such risk factor of particular relevance to suicide
      in adolescence is state-sensitive aspects of impulsivity. Impulsivity has been consistently
      linked with suicidality, with this association appearing to be stronger in adolescence than
      adulthood. As a first step toward investigating whether modulation of impulsivity and
      associated neural pathways may yield clinically meaningful changes in risk for adolescent
      suicidal behavior, the R21 is a proof-of concept study evaluating the potential for tDCS
      targeting brain regions associated with behavioral impulsivity (right inferior frontal gyrus
      [rIFG]) and cognitive impulsivity (left orbitofrontal cortex [lOFC]) to modulate these facets
      of impulsivity in a sample of adolescent suicide attempters. Participants will be randomly
      assigned to receive anodal tDCS over the rIFG, anodal tDCS over the lOFC, or a sham
      stimulation condition, in a three-group design. Task-based measures of behavioral and
      cognitive impulsivity will be administered before and after tDCS or sham stimulation.
      Additionally, EEG and ERP data will be collected during the impulsivity tasks, and
      resting-state EEG data will be collected pre- and post-tDCS administration to confirm
      engagement of the targeted brain regions and to delineating the neural pathways underlying
      the effects of tDCS on impulsivity.
    

Intervention name(s): anodal tDCS over the rIFG,; anodal tDCS over the lOFC,; sham tDCS stimulation condition
Intervention type(s): Device; Device; Device
Intervention description(s): tDCS at a constant current of 1.5 milliampere (mA) will be applied for one 20-minute session over the right inferior frontal gyrus . Resting-state EEG for 10 minutes will be recorded immediately prior to and after tDCS. After post-tDCS resting state EEG is acquired, EEG is recorded to extract Evoked Response Potentials in a single-blind procedure. The participants and assessors will be blind to experimental condition.; tDCS at a constant current of 1.5 mA will be applied for one 20-minute session over the left orbitofrontal cortex . Resting-state EEG for 10 minutes will be recorded immediately prior to and after tDCS. After post-tDCS resting state EEG is acquired, EEG is recorded to extract Evoked Response Potentials in a single-blind procedure. The participants and assessors will be blind to experimental condition.; In the sham condition, the current will be ramped up to 1.5 mA for 30 seconds and then ramped back down to 0. As this commonly used sham procedure produces a brief tingling sensation, participants are kept unaware of their experimental condition. Resting-state EEG for 10 minutes will be recorded immediately prior to and after the sham tDCS. After post-sham stimulation resting state EEG is acquired, EEG is recorded to extract Evoked Response Potentials in a single-blind procedure. The participants and assessors will be blind to experimental condition.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: anodal tDCS over the rIFG, anodal tDCS over the lOFC, sham stimulation condition
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Diagnostic