Polysubstance Use Has Many Consequences

Cocaine, psychostimulant, and opioid deaths continue to climb. In 2017, close to 20% of US drug overdose deaths involved cocaine, up 34.4% from 2016, and nearly three-fourths of the cocaine-involved deaths also involved opioids, according to a CDC report. Deaths that involved psychostimulants represented 14.7% of drug overdose deaths, up 37% from 2016, and about half of these deaths also involved opioids. Deaths that involve cocaine and psychostimulants continued to increase in 2018.

Polysubstance opioid overdose deaths outnumber opioid-only deaths. About 83% of opioid-related overdose deaths that had accompanying toxicology results in Massachusetts in 2014 and 2015 involved an opioid and another substance. Opioids-only use accounted for 17% of the deaths; opioids plus stimulants, 36%; and opioids plus another nonstimulant substance, 46%. Persons more likely to die with the use of opioids and stimulants included those older than 24 years, nonrural residents, those with comorbid mental illness, non-Hispanic black residents, and those with recent homelessness.

With marijuana, alcohol, and tobacco, one thing leads to another. In a recent study, alcohol, cigarettes, or marijuana use increased the odds of same-day co-use of 1 of the other substances and co-use of 2 of the substances generally increased the likelihood of tri-use with the third. The relationship between alcohol or cigarette use predicting marijuana co-use was stronger in men; observed additive relationships of drug co-use leading to tri-use were stronger in women.

Polysubstance use disorder influences treatment outcomes in vets with PTSD. Among veterans with a substance use disorder (SUD) and posttraumatic stress disorder (PTSD) receiving integrated, exposure-based treatment, those with poly-SUD had greater reductions in percent days using substances than those with a single SUD. Those with a single SUD had greater reductions in PTSD symptom severity than those with poly-SUD over the course of treatment. Future research is recommended to identify ways to enhance treatment outcomes for patients with poly-SUD.

Simultaneous polysubstance depictions cue cravings. Recent study findings support the incentive sensitization model-alcohol and marijuana cues facilitated craving for both alcohol and marijuana more than when they were depicted in isolation for high and low users of each substance. “Theoretically, this study supports the notion that simultaneous and repeated use of multiple substances results in greater hypersensitivity and craving to mediated polysubstance cues than the cues in isolation,” the authors noted.

Polysubstance use predicts criminality. In a study designed to identify subgroups of psychiatric populations at risk for violence and criminality, persistent polysubstance use (cannabis, cocaine, and alcohol) was a strong predictor for high criminality. Others were male sex, lower educational level, higher score of psychopathy, and persistent cannabis use (alone). Best predictors for high violence were low verbal intelligence, higher psychopathy and anger scores, persistent cannabis use (alone), and persistent moderate affective symptoms.

Heroin consequences depend on other substances used. Polysubstance use is typical among regular heroin users, but risks vary with the substances used. Heroin consequences were associated with regular misuse of sedatives but not with regular alcohol use, although persons who regularly use alcohol were more likely to regularly use other substances. Knowledge of subgroup differences is critical for understanding substance use motivations and creating avenues for harm reduction, study authors concluded.

Buprenorphine mediates heroin and kratom use. Kratom has long been used In Asia to reduce alcohol and drug dependence, but its usefulness and safety remain unclear. Among polysubstance users enrolled in recovery programs, those who reported past-year heroin use were 2.5 times more likely to also report past-year kratom use. Past-year prescription opioid use was not significantly associated with kratom use. Non-prescribed buprenorphine (Suboxone) use partially mediated the relationship between past-year heroin and kratom use. Kratom was not preferred over heroin or prescription opioids.