Obsessive-compulsive disorder (OCD) is associated with substantial impairments in quality of life and is among the most disabling psychiatric disorders. Exposure therapy is among the first-line of treatments for obsessive-compulsive disorder (OCD) . Extinction learning is thought to be a core mechanism of therapeutic exposure. Fear and safety signal learning are traditionally associated with activity and connectivity within the canonical corticolimbic "fear circuit", which includes the amygdala, medial prefrontal cortex (mPFC), and hippocampus. Transcranial direct current stimulation (tDCS) is a neuromodulation technology that can augment brain plasticity, learning, and memory. The proposed study will test if obsessive-compulsive disorder (OCD) is associated with inhibitory safety learning deficits and if transcranial direct current stimulation (tDCS) normalizes functional connectivity and safety signal processing to recover extinction deficits in obsessive-compulsive disorder (OCD).
Age range
18 Years – 70 Years
Sex
ALL
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Blood oxygen level-dependent (BOLD) response to create functional brain activation maps
Timeframe: Blood oxygen level-dependent (BOLD) will be measured across 3 daily scan sessions separated by ~24 hours each; data will be reported from all 3 sessions.
Skin conductance response (SCR) will be measured by collecting electrodermal activity data from the left hand
Timeframe: Skin conductance will be measured across all 3 scan sessions, separated by ~24 hours each; data will be reported from all 3 sessions.
Threat expectancies will be measured by asking participants to rate the probability of receiving a shock using a 0-100 scale with zero equal to 0% chance and 100 equal to 100% chance; higher values are indicative of worse anxious reactivity
Timeframe: Threat expectancies will be assessed at the beginning and end of each of the 3 scan session, separated by ~24-hours each; data will be reported from all 3 sessions.
Functional brain connectivity will be measured blood oxygen level dependent (BOLD) response
Timeframe: Resting functional connectivity will be measured at baseline during first scan session and during transcranial direct current stimulation in the second scan session; scan sessions will be separated by ~24 hours; data from both sessions will be reported.