Startle-elicited Event-Related Potentials to Affective Stimuli are Associated with Recent Illicit Opioid use among Patients Receiving Opioid Agonist Treatment

Opioid use disorder (OUD) has been linked to exaggerated attentional, affective, and arousal responses to opioid-related stimuli, as well as altered responses to other affective (eg, naturally rewarding or aversive) stimuli, particularly blunted responses to pleasant/rewarding stimuli. Both exaggerated responses to drug-related stimuli and reduced response to pleasant stimuli may influence the course of OUD and its treatment, however interpretation of studies thus far is limited by methodological issues. In the present study, we examined subjective ratings, and attenuation of the P3 component of the acoustic startle-evoked event-related potential (as a measure of attention), while viewing neutral, pleasant, unpleasant, and drug-related images. Participants prescribed opioid agonist treatment (OAT) for OUD (n = 82) were compared to a carefully-matched control group (n = 33) and to recently-abstinent participants with OUD (n = 22). Relative to controls, participants prescribed OAT gave higher positive valence ratings of drug images, and blunted valence responses to other affective images, but groups did not differ in terms of arousal ratings or P3 amplitude. Within the OAT group, linear modeling of associations between frequency of recent illicit opioid use and startle P3 amplitude found an association between increased recent illicit opioid use and reduced attention to pleasant, relative to unpleasant, images. The latter finding may have implications for interventions targeting cognitive biases in people with substance use disorder. In particular, they suggest that enhancing attention to pleasant stimuli may be as, if not more important, than the typical approach of trying to reduce attentional bias to drug-related stimuli.

Treatment of opioid use disorder in primary care

Opioid use disorder (OUD) is a common, treatable chronic disease that can be effectively managed in primary care settings. Untreated OUD is associated with considerable morbidity and mortality—notably, overdose, infectious complications of injecting drug use, and profoundly diminished quality of life. Withdrawal management and medication tapers are ineffective and are associated with increased rates of relapse and death. Pharmacotherapy is the evidence based mainstay of OUD treatment, and many studies support its integration into primary care settings. Evidence is strongest for the opioid agonists buprenorphine and methadone, which randomized controlled trials have shown to decrease illicit opioid use and mortality. Discontinuation of opioid agonist therapy is associated with increased rates of relapse and mortality. Less evidence is available for the opioid antagonist extended release naltrexone, with a meta-analysis of randomized controlled trials showing decreased illicit opioid use but no effect on mortality. Treating OUD in primary care settings is cost effective, improves outcomes for both OUD and other medical comorbidities, and is highly acceptable to patients. Evidence on whether behavioral interventions improve outcomes for patients receiving pharmacotherapy is mixed, with guidelines promoting voluntary engagement in psychosocial supports, including counseling. Further work is needed to promote the integration of OUD treatment into primary care and to overcome regulatory barriers to integrating methadone into primary care treatment in the US.

Are prescription misuse and illicit drug use etiologically distinct? A genetically-informed analysis of opioids and stimulants

Background Drug classes are grouped based on their chemical and pharmacological properties, but prescription and illicit drugs differ in other important ways. Potential differences in genetic and environmental influences on the (mis)use of prescription and illicit drugs that are subsumed under the same class should be examined. Opioid and stimulant classes contain prescription and illicit forms differentially associated with salient risk factors (common route of administration, legality), making them useful comparators for addressing this etiological issue. Methods A total of 2410 individual Australian twins [Mage = 31.77 (s.d. = 2.48); 67% women] were interviewed about prescription misuse and illicit use of opioids and stimulants. Univariate and bivariate biometric models partitioned variances and covariances into additive genetic, shared environmental, and unique environmental influences across drug types. Results Variation in the propensity to misuse prescription opioids was attributable to genes (41%) and unique environment (59%). Illicit opioid use was attributable to shared (71%) and unique (29%) environment. Prescription stimulant misuse was attributable to genes (79%) and unique environment (21%). Illicit stimulant use was attributable to genes (48%), shared environment (29%), and unique environment (23%). There was evidence for genetic influence common to both stimulant types, but limited evidence for genetic influence common to both opioid types. Bivariate correlations suggested that prescription opioid use may be more genetically similar to prescription stimulant use than to illicit opioid use. Conclusions Prescription opioid misuse may share little genetic influence with illicit opioid use. Future research may consider avoiding unitary drug classifications, particularly when examining genetic influences.

Facing drug addiction: Vietnam’s struggle with opioids

Drug addiction is a historical issue in Vietnam. Although Vietnam has a long history as a producer of opium poppies and crossroads for the illicit drug trade, it is now has some of the most stringent drug laws in the world. Vietnam has shown some success in reducing the production, trade, and transportation of narcotics. There has also been a shift in the attitudes of lawmakers and government authorities toward viewing drug abuse as a health problem rather than a social vice. Educating and encouraging citizens to collaboratively reduce drug use has also proven effective. However, despite these changes, the number of people who use drugs has increased in recent years. The US, too, has also experienced an increase in illicit opioid use. The Trump administration declared opioid addiction a public health emergency and has established goals to address the crisis. The results of these efforts have also been uneven. This article reviews Vietnam’s efforts to tackle its opioid epidemic, with the goal of identifying areas where Vietnam’s approach to opioid addiction may be improved. A brief overview of efforts by the U.S. government, an important foreign partner for Vietnam in the control of illicit opioids, serves to demonstrate the difficulty of treating opioid use in different political systems.

Healthcare use by people who use illicit opioids (HUPIO): development of a cohort based on electronic primary care records in England

Background: People who use illicit opioids such as heroin have substantial health needs, but there are few longitudinal studies of general health and healthcare in this population. Most research to date has focused on a narrow set of outcomes, including overdoses and HIV or hepatitis infections. We developed and validated a cohort using UK primary care electronic health records (Clinical Practice Research Datalink GOLD and AURUM databases) to facilitate research into healthcare use by people who use illicit opioid use (HUPIO). Methods: Participants are patients in England with primary care records indicating a history of illicit opioid use. We identified codes including prescriptions of opioid agonist therapies (methadone and buprenorphine) and clinical observations such as ‘heroin dependence’. We constructed a cohort of patients with at least one of these codes and aged 18-64 at cohort entry, with follow-up between January 1997 and March 2020. We validated the cohort by comparing patient characteristics and mortality rates to other cohorts of people who use illicit opioids, with different recruitment methods. Results: Up to March 2020, the HUPIO cohort included 138,761 patients with a history of illicit opioid use. Demographic characteristics and all-cause mortality were similar to existing cohorts: 69% were male; the median age at index for patients in CPRD AURUM (the database with more included participants) was 35.3 (IQR 29.1-42.6); the average age of new cohort entrants increased over time; 76% had records indicating current tobacco smoking; patients disproportionately lived in deprived neighbourhoods; and all-cause mortality risk was 5.4 (95% CI 5.3-5.5) times the general population of England. Conclusions: Primary care data offer new opportunities to study holistic health outcomes and healthcare of this population. The large sample enables investigation of rare outcomes, whilst the availability of linkage to external datasets allows investigation of hospital use, cancer treatment, and mortality.