Polydrug Definition and Assessment: The State of the Art

A study into the nature and extent of polydrug use in driving recidivism behavior

OBJECTIVE

Polydrug use has become a frequent pattern of drug consumption in Europe, and this is considered a particularly dangerous risk factor for impaired driving. In Italy, persons whose license has been revoked or suspended due to the use of psychoactive drugs can reapply for a new driving license, depending on the judgment of the relevant local medical committee (CML). To regain a revoked license, offenders must remain drug free throughout an observation period. An important problem with enforcement of impaired driving is recidivism. The aim of the present study is to analyze the influence of polydrug use on driving recidivism.

METHOD

We report the findings of several years' experience at the forensic toxicology laboratory of the University of Macerata. Hair samples collected over a 7-year period by the CML from drug users were analyzed for cocaine, opiates, and cannabis using gas chromatography-mass spectrometry.

RESULTS

Three hundred thirty-five of the tested subjects were recidivists. Recidivism was more frequent among monodrug users (81%) compared with polydrug users (19%), but logistic regression showed that polydrug use is certainly a risk factor for recidivism compared to monodrug use (odds ratio [OR] = 1.99). The sex and age distribution of recidivist subjects showed a strong predominance of males in both groups, but there were no sex differences. There were more recidivist polydrug users than recidivist monodrug users in the younger age groups (OR = 2.012). Cocaine use was most prevalent in the recidivist monodrug group. All drugs analyzed were demonstrated to be a risk factor for recidivism among monodrug users, whereas only the cocaine and cannabis combination was shown to be a risk factor for recidivism among polydrug users (OR = 1.65 versus cocaine; OR = 1.30 versus Δ9-tetrahydrocannabinol). Almost all polydrug users became monodrug users, and cocaine was the most frequently detected drug in the subsequent test during the monitoring phase.

CONCLUSIONS

Our results show that polydrug use increases the risk of impaired driving recidivism and represents a considerable threat to road safety.

Chronic Voluntary Morphine Intake Is Associated with Changes in Brain Structures Involved in Drug Dependence in a Rat Model of Polydrug Use

Chronic opioid intake leads to several brain changes involved in the development of dependence, whereby an early hedonistic effect (liking) extends to the need to self-administer the drug (wanting), the latter being mostly a prefrontal-striatal function. The development of animal models for voluntary oral opioid intake represents an important tool for identifying the cellular and molecular alterations induced by chronic opioid use. Studies mainly in humans have shown that polydrug use and drug dependence are shared across various substances. We hypothesize that an animal bred for its alcohol preference would develop opioid dependence and further that this would be associated with the overt cortical abnormalities clinically described for opioid addicts. We show that Wistar-derived outbred UChB rats selected for their high alcohol preference additionally develop: (i) a preference for oral ingestion of morphine over water, resulting in morphine intake of 15 mg/kg/day; (ii) marked opioid dependence, as evidenced by the generation of strong withdrawal signs upon naloxone administration; (iii) prefrontal cortex alterations known to be associated with the loss of control over drug intake, namely, demyelination, axonal degeneration, and a reduction in glutamate transporter GLT-1 levels; and (iv) glial striatal neuroinflammation and brain oxidative stress, as previously reported for chronic alcohol and chronic nicotine use. These findings underline the relevance of polydrug animal models and their potential in the study of the wide spectrum of brain alterations induced by chronic morphine intake. This study should be valuable for future evaluations of therapeutic approaches for this devastating condition.

High-risk polysubstance use among LGBTQ+ people who use drugs in the United States: An application of syndemic theory

BACKGROUND

Compared to heterosexual and cisgender people, lesbian, gay, bisexual, transgender, queer, and other sexual and gender minority (LGBTQ+) people are more likely to develop problems with high-risk polysubstance use. According to syndemic theory, this disparity in high-risk polysubstance use is produced by the LGBTQ+ community's increased vulnerability to experiencing psychosocial (e.g., discrimination, unwanted sex) and structural (e.g., food insecurity, homelessness) conditions, greater likelihood of coping with concurrent health problems (e.g., human immunodeficiency virus [HIV]), and decreased opportunities to develop protective factors (e.g., social support, resilience).

METHODS

Data from 306 LGBTQ+ participants living in the United States (U.S.) with a lifetime history of alcohol and drug use were analyzed; 21.2% reported lifetime problems with 10 different drugs. Bootstrapped hierarchical multiple regression was used to test demographic correlates and syndemic predictors of high-risk polysubstance use. One-way ANOVA and post-hoc comparison tests were used to test subgroup differences by gender.

RESULTS

Results indicated that income, food insecurity, sexual orientation-based discrimination, and social support were associated with high-risk polysubstance use, explaining 43.9% of the variance of high-risk polysubstance use. Age, race, unwanted sex, gender identity-based discrimination, and resilience were not significant. Group comparison tests revealed that, compared to nonbinary people and cisgender sexual minority men and women, transgender individuals experienced significantly higher levels of high-risk polysubstance use and sexual orientation-based discrimination but significantly lower levels of homelessness and social support.

CONCLUSION

This study provided further evidence for conceptualizing polysubstance use as an adverse outcome of syndemic conditions. Harm reduction strategies, anti-discrimination laws, and gender-affirming residential treatment options should be considered in U.S. drug policy. Clinical implications include targeting syndemic conditions to reduce high-risk polysubstance use among LGBTQ+ people who use drugs.

Predictors and motives of polydrug use in opioid users. A narrative review

PURPOSE OF REVIEW

To review the recent literature on predictors and personal motives of polydrug use in opioid users with a focus on combined use of opioids with stimulants, benzodiazepines and gabapentinoids.

RECENT FINDINGS

In North America, methamphetamine is now the most prevalent co-drug in opioid users and is responsible for high mortality rates. In Europe, opioids are rather combined with either cocaine, benzodiazepines or gabapentionoids, but recent data are lacking.Main personal motives of opioid users to combine opioids with methamphetamine or cocaine is to boost the opioid high, inhibit the withdrawal effects of heroin and have a cheaper alternative to maintain the opioid high. Risk factors of polydrug use by opioid users included being male, younger age, homelessness, high-risk sexual behavior, needle sharing, incarceration, poor mental health and recent use of cocaine or prescription opioids. The motives for co-use of opioids and gabapentinoids also include seeking a better high, lower price and to self-medicate pain/physical symptoms, including those resulting from withdrawal.

SUMMARY

When treating opioid users with polydrug drug use, special attention should be paid to dosing when in opioid agonist methadone/buprenorphine treatment and to the presence of physical pain. The validity of part of the personal motives seems questionable which deserves attention when counselling opioid users with polydrug use.