The role of social connection in opioid use disorder treatment engagement.

OBJECTIVE: Medications for opioid use disorder (OUD or MOUD) treatment combining pharmacotherapy with psychosocial support are effective for managing OUD. However, treatment engagement remains a challenge, with retention rates ∼30%-50%. Although social connection has been identified as important to recovery, it remains unclear whether and how social factors can bolster participation in treatment. METHOD: Individuals receiving MOUD at three outpatient treatment programs (N = 82) and healthy community controls (N = 62) completed validated measures assessing social connection including (a) size, diversity, and embeddedness of social networks; (b) perceived social support and criticism within familial relationships; and (c) subjective social status. For those receiving MOUD, we also examined how aspects of social connection related to opioid (re)use and treatment engagement (medication adherence, group, and individual meeting attendance) assessed over ∼8 weeks/person. RESULTS: Compared to controls, individuals receiving MOUD had smaller and less diverse and embedded social networks (Cohen's d > 0.4), and despite similar levels of perceived social support (d = 0.02), reported higher levels of social criticism (d = 0.6) and lower subjective social status (d = 0.5). Within the MOUD group, higher social network indices correlated specifically with higher therapeutic group attendance (Rs > 0.30), but not medication adherence, while higher levels of perceived criticism correlated with more frequent opioid use (R = 0.23). Results were mostly robust to control for sociodemographic variables, psychological distress/COVID-19, and treatment duration, but differed by MOUD type/program. CONCLUSIONS: These findings highlight the potential importance of assessing an individual's social capital, promoting positive social connection, and continuing to assess the implementation and value of psychosocial support in MOUD treatment. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Computational theory-driven studies of reinforcement learning and decision-making in addiction: What have we learned?

Computational psychiatry provides a powerful new approach for linking the behavioral manifestations of addiction to their precise cognitive and neurobiological substrates. However, this emerging area of research is still limited in important ways. While research has identified features of reinforcement learning and decision-making in substance users that differ from health, less emphasis has been placed on capturing addiction cycles/states dynamically, within-person. In addition, the focus on few behavioral variables at a time has precluded more detailed consideration of related processes and heterogeneous clinical profiles. We propose that a longitudinal and multidimensional examination of value-based processes, a type of dynamic "computational fingerprint", will provide a more complete understanding of addiction as well as aid in developing better tailored and timed interventions.

Targeting the perivascular niche sensitizes disseminated tumour cells to chemotherapy.

The presence of disseminated tumour cells (DTCs) in bone marrow is predictive of poor metastasis-free survival of patients with breast cancer with localized disease. DTCs persist in distant tissues despite systemic administration of adjuvant chemotherapy. Many assume that this is because the majority of DTCs are quiescent. Here, we challenge this notion and provide evidence that the microenvironment of DTCs protects them from chemotherapy, independent of cell cycle status. We show that chemoresistant DTCs occupy the perivascular niche (PVN) of distant tissues, where they are protected from therapy by vascular endothelium. Inhibiting integrin-mediated interactions between DTCs and the PVN, driven partly by endothelial-derived von Willebrand factor and vascular cell adhesion molecule 1, sensitizes DTCs to chemotherapy. Importantly, chemosensitization is achieved without inducing DTC proliferation or exacerbating chemotherapy-associated toxicities, and ultimately results in prevention of bone metastasis. This suggests that prefacing adjuvant therapy with integrin inhibitors is a viable clinical strategy to eradicate DTCs and prevent metastasis.