Study ended prematurely due to PI departing institution for another position.

Even when treated with methadone or buprenorphine maintenance, many people with opioid use disorder (OUD) continue to experience craving. Among both users of heroin and users of prescription opioids, mounting evidence shows that craving predicts return to use and undermines existing treatments for OUD, thus, the development of new interventions to reduce craving is a priority for addressing the opioid crisis (NIH HEAL Initiative Research Plan, 2019). Deficits in executive functioning, particularly working memory, are a central mechanism that undermines the ability to inhibit craving. Laboratory studies in non-clinical samples show that engaging in working memory tasks before or during a craving induction increases the ability to resist craving.

This suggests that people with OUD may benefit from engaging in working memory tasks at the specific moment when craving occurs. Although previous research shows that working memory "training" does not improve clinical outcomes in OUD, these studies have not delivered training at the moment that craving actually occurs in daily life. Thus, engaging in working memory tasks at the moment that craving occurs could presumably help individuals with OUD to manage this persistent symptom, but this has not been tested.

Further, studies using Ecological Momentary Assessment (EMA) methods show that people with OUD can accurately track moment-to-moment fluctuations in craving in their daily lives, suggesting that it may be feasible to deliver interventions for craving in the moment when craving is reported. This study will test the efficacy of embedding a mobile cognitive intervention into an EMA design in people with OUD. Using the NIH Stage Model of Intervention Development, Stage 1A of this project will optimize a working memory intervention based on iterative feedback from a sample of people with OUD (n = 20), in preparation for a Stage 1B trial using a randomized design. In this trial, participants with OUDs (n = 60) will complete a two-week EMA study in which they complete smartphone-based assessments of craving five times daily. When craving is reported, a mobile application containing the working memory intervention will activate. Half of the participants will complete the intervention, while half will complete a control task. At the conclusion of the trial, participants will be granted unrestricted access to the intervention during a feasibility phase. Outcomes include change in momentary craving, change in working memory performance, and feasibility and acceptability, including use of the intervention during follow-up. Substance use will also be assessed. This project supports the applicant's goal of leveraging cognitive mechanisms to conduct treatment development research for OUD. The applicant will receive training in the etiology and treatment of OUD, craving, mobile intervention development and human-centered design of interventions, and analysis of intensive longitudinal data. With its emphasis on modifying cognitive processes at the moment of craving, using mobile devices in patients' daily lives, this project has the potential to reveal new pathways for addressing a significant predictor of relapse in OUD.

Inclusion Criteria:

• Age 18 or older
• Currently receiving opioid use disorder treatment at McLean Hospital
• Primary diagnosis of opioid use disorder
• Currently prescribed medication treatment (agonist/partial agonist or antagonist) for opioid use disorder (*Note: does not apply to Stage 1A participants).
• Own a smartphone with a touchscreen and a current data plan

Exclusion Criteria:

• Acute suicidal ideation
• Acute psychosis
• Diagnosis of a neurological disorder
• History of stroke
• Diagnosis of a brain disease affecting cognitive function (e.g., tumor)
• Score of less than 26 on the Montreal Cognitive Assessment (MoCA)

Baseline participants in this phase did not enter into either of the study's intervention arms; by design, these participants provided feedback about the Stage 1B clinical trial design.

1 hour

This study was terminated prior to enrolling participants in either of the clinical trial study arms, so the number of participants at risk for Serious Adverse Events in the planned clinical trial is zero. All-cause mortality, and Other Adverse Events is 0 for both study arms.

In addition, there were no Serious Adverse Events nor Other Adverse Events recorded in the participants enrolled in the Stage 1A phase (n = 10 participants total).

This study was terminated prior to enrolling participants in either of the clinical trial study arms, so no outcome data were collected. Baseline data on the 10 participants who entered the Stage 1A study (designed to help inform the development of the clinical trial) are provided in the Baseline Characteristics section.