Approximately 1 in 3 high school seniors (31.8%) who reported misusing prescription opioids as high school seniors between 1997 and 2000 went on to use heroin by age 35, according to a study conducted by the University of Michigan.

Additionally, the researchers observed that 21% of seniors during that same time period who misused prescription opioids and later received an opioid prescription used heroin by age 35.

"It is a very timely study given the number of adolescents and young adults who were overprescribed opioids and who are now aging into adulthood," said lead author Sean Esteban McCabe, PhD, professor and director of the Center for the Study of Drugs, Alcohol, Smoking and Health at the University of Michigan School of Nursing, in a press release. "We need to follow these generations to assess their risk for developing later problems."

The researchers focused specifically on high school seniors within 25 cohorts between 1976 and 2000. The team followed them from age 18 to 35 using data on these 11,012 individuals from the national Monitoring the Future study, which was funded by the National Institute on Drug Abuse.

The team found that unlike earlier cohorts, the individuals from this cohort who were seniors between 1997 and 2000 and reported prescription opioid misuse had a dramatically increased risk for later heroin use compared with students who didn't misuse prescription opioids. The 1997 to 2000 cohort consisted of 1059 individuals in total.

The study co-author Philip Veliz, research assistant professor at the University of Michigan School of Nursing, explained in a press release that this may be a reflection of the trend of overprescribing opioids during this time.

"There was an increase in opioid prescribing in the 1990s and 2000s that contributed to the opioid epidemic," Veliz said. "Health professionals and the larger public health community owe it to these individuals to understand the downstream effects of overprescribing and develop effective interventions."

The findings may explain the large uptick in heroin use among the more recent cohorts and may partially explain why opioid overdoses have skyrocketed in recent years, Veliz noted.

"These prevalence estimates of heroin use are very high, considering the general population annual estimates are less than 1%," McCabe said. "And anyone in the study with a history of heroin use at baseline was excluded, which makes the findings more conclusive."

According to national estimates, heroin users in the United States increased from 373,000 in 2007 to 808,000 in 2018, with the largest increase occurring among adults aged 26 years and older.

The researchers noted that although the vast majority of exposure to prescription opioids does not lead to heroin use, the incidence and prevalence rates of heroin use were far greater among individuals who reported prescription opioid misuse.

"There are several generations who were overprescribed controlled medications with high misuse potential, such as opioids," McCabe said. "Prescribing fewer opioids and the correct dosage is only one piece to the puzzle. The solution requires a much more comprehensive plan that includes better education, screening and interventions to reach high-risk individuals who often fly under the radar in many health care settings. We all played a role in creating the opioid crisis and we owe it to these individuals to address the problem."

REFERENCE
From pills to powder: 1 in 3 high school seniors who misused prescription opioids later used heroin. Ann Arbor, MI: University of Michigan; October 20, 2020. eurekalert.org/pub_releases/2020-10/uom-fpt102020.php. Accessed October 26, 2020.