Piloting a Personalized Computerized Inhibitory Training Program for Individuals with Obsessive-Compulsive Disorder

pleted eight 60-min in-person ERP sessions (modified from Kozak and Foa [6] ) with a trained therapist delivered over 2.5 weeks (mean 18 days; SD = 4 days). At week 0 (baseline), an independent evaluator conducted the Yale-Brown Obsessive Compulsive Scale (Y-BOCS [7] ), and patients completed the Stroop and the stop signal tasks, and 3 selfreport measures (Obsessive Compulsive Inventory-Revised, OCIR [8] , Obsessive Beliefs Questionnaire-44, OBQ-44 [9] , and Beck Depression Inventory II, BDI-II [10] ). At week 1 (following P-CIT training), participants repeated the Y-BOCS. At week 3 (following P-CIT + ERP), participants repeated the week 0 measures and an acceptability and feasibility questionnaire (11 five-point Likert items that assessed their experience with P-CIT). Eleven adults with a principal diagnosis of OCD (duration of ≥ 1 year) who completed at least 1 trial of high-quality ERP ( ≥ 15 one-hour weekly ERP sessions conducted by an OCD expert) in the past 2 years but still had Y-BOCS ≥ 16 ( Table 1 ) participated. Eligibility was determined by a trained clinician using the Structured Clinical Interview for DSM-5. Exclusion criteria were lifetime mania or psychosis, and current major depressive disorder, suicidality, or substance use disorder warranting clinical intervention. Patients on psychiatric medication had been on a stable dose for at least 6 weeks prior to study entry and remained on this dose throughout the study. The Stroop Task assesses interference and task control [for a description, see 4 ]. Changes in Stroop congruent and incongruent trials, but not in neutral trials or the overall Stroop effect (incongruent-congruent), are hypothesized to be a signature of task control [11] . The “Stop-it” [12] version of the stop signal task assessed response inhibition. On each trial, participants had to quickly identify a visual go stimulus (a white square or circle). On a random selection of 25% of the trials, after the appearance of the go stimulus, an auditory stop signal occurred after a variable duration (stop signal duration) that was initially set at 250 ms and adjusted by a staircase tracking procedure. Stop signal reaction time (RT) was calculated for each patient using “Analyze-it” [12] . P-CIT was modified from the stop signal task using Python2.7. 6. Half of the trials consisted of personalized OCD-related pictures, and the other half of neutral pictures. A stop signal occurred in 80% of the OCD-related trials and in 20% of the neutral trials. Patients had to respond as quickly and as accurately as possible to the background color of the picture (light vs. dark) by pressing the keyboard, unless they heard the stop signal. To personalize the task, the OCD-related pictures were selected by the patient and ERP therapist to ensure they trigger anxiety/distress and updated over time to ensure they continued to trigger anxiety/distress. Images were taken from the International Affective Picture System [13] and other online resources (e.g., Google images). Patients e-mailed de-identified data to the first author from the P-CIT program daily. Exposure and ritual prevention (ERP) treats obsessive-compulsive disorder (OCD), but only some patients achieve minimal symptoms at treatment completion [1] . Since patient adherence to ritual prevention strongly predicts ERP outcome [2] , improving patients’ ability to inhibit compulsions may improve ERP outcome. Recent OCD models suggest that a fundamental disruption in the ability to inhibit action, or overreliance on stimulus-driven habits, leads to compulsions [3] . Inhibition of unwanted/irrelevant “stimulus-driven” behaviors is governed by a proactive executive process called task control [4] . Deficits in task control are associated with OCD symptom severity [5] and have been hypothesized to underlie patients’ ability to inhibit compulsions during ERP (regardless of whether disruption in task control is a fundamental preexisting deficit or the consequence of anxiety/distress). Thus, improving task control might help achieve better ERP outcomes. We developed a program intended to enhance task control over compulsive behaviors – personalized-computerized inhibitory training (P-CIT). P-CIT seeks to improve the patient’s ability to inhibit responses while exposed to images that were related to their specific OCD symptoms. To explore feasibility, acceptability, and preliminary efficacy, we tested P-CIT in 11 individuals with OCD, who had significant symptoms despite prior high-quality ERP trials. We hypothesized that combining P-CIT and ERP would reduce OCD symptoms and improve performance on cognitive tasks assessing response inhibition and task control. This study was conducted at New York State Psychiatric Institute/Columbia University Medical Center (clinicaltrial.gov identifier: NCT02378896). First, patients trained with P-CIT (on their personal computer) for 7 consecutive days (three 15-min sessions/ day). Next, while continuing with P-CIT training, patients comReceived: April 10, 2017 Accepted after revision: September 1, 2017 Published online: January 6, 2018