for people ages 18-65 (full criteria)
healthy people welcome
study started
estimated completion
Reza Tadayon-Nejad(ucla)



Dysfunctional decision-making may be a prominent mechanism underlying maladaptive behavior in multiple psychiatric disorders, including obsessive-compulsive disorder (OCD). Debilitating compulsivity and avoidance in OCD is believed to be a direct result of flawed decision-processing. A better understanding of the brain mechanisms of abnormal decision-making in OCD is essential for the development of more effective treatment options. This mentored patient-oriented research career development project plans to address this underexplored area. People utilize two behavioral strategies, goal-directed (GD) and habitual (HB), when engaging in value-based decision-making that involves rewarding or punishing outcomes. Furthermore, an arbitration mechanism has been proposed recently that controls the balance between those two strategies in healthy subjects. Arbitration regions (the frontopolar and inferolateral prefrontal cortex (ilPFC)) regulate the goal-directed/habitual decision-making balance by selectively downregulating the activity of the habitual regions (putamen and supplementary motor area). In OCD, an imbalance exists between GD and HB action selection in favor of HB action selection. This project aims to explore the neurobehavioral characteristics of arbitration mechanism and its relationship with behaviors and clinical phenotypes in OCD by applying cognitive neuroscience, clinical task-based fMRI and transcranial direct current stimulation (tDCS) approaches. Adults with OCD and healthy control participants will perform two tasks while being scanned, and when they receive inhibitory, excitatory and sham tDCS over the left ilPFC outside scanner: I) a decision-making task in which GD and HB strategies compete to control action selection and II) a clinically relevant symptom provocation-avoidance task in which avoidance decisions will be simulated. The project's research aims are to 1) explore the GD, HB and arbitration regions' neural activity and arbitration-habitual circuit connectivity in OCD; 2) examine the association between measures of behavioral performance, arbitration's neural and connectivity, and OCD clinical symptoms; and 3) investigate the behavioral consequences of tDCS over an arbitration region, the left ilPFC, during tasks performance.


OCD Decision-Making tDCS fMRI Compulsive Personality Disorder Obsessive-Compulsive Disorder


For people ages 18-65

A) OCD participants inclusion criteria:

  1. DSM-5 diagnostic criteria for OCD as primary (most severe) diagnosis (based on the Mini International Neuropsychiatric Interview).
  2. Yale-Brown Obsessive-Compulsive Scale (YBOCS) total score is equal or greater than 16.
  3. unmediated or being on a stable dose of medication (only SSRIs and clomipramine) for at least 12 weeks prior to the study.
  4. fluent English speaker.
  5. signed informed consent.

B) OCD participants exclusion criteria:

  1. IQ greater than 80 on the Wechsler Abbreviated Scales of Intelligence.
  2. lifetime DSM-5 diagnosis of mania, psychotic disorder, or substance dependence (per MINI).
  3. current DSM-5 diagnosis of MDD if Montgomery-Asberg Depression Scale (MADRS) scores are equal or greater than 35 (severe), or ADHD.
  4. taking any psychotropic medication other than SSRIs or clomipramine.
  5. severe psychiatric symptom that requires immediate inpatient psychiatric intervention such as suicidality.
  6. presence of any serious psychiatric, psychosocial, or neurological condition requiring immediate treatment.

C) Healthy control inclusion criteria:

1-males and females age 18-65 years with signed informed consent and IQ greater than 80 on WASI.

D) Exclusion criteria for all participants:

  1. presence of any MR scan contraindications particularly body metal or positive pregnancy test.
  2. medical conditions in which cerebral metabolism might be compromised such as thyroid disorders, diabetes or current tobacco smoking (potential effect on imaging endpoints).
  3. any history of seizure disorders.


  • UCLA accepting new patients
    Los Angeles California 90095 United States

Lead Scientist


accepting new patients
Start Date
Completion Date
University of California, Los Angeles
Study Type
Last Updated