NMU of prescription stimulant medications (RxStim) intended for treatment of attention deficit/hyperactivity disorder (ADHD) is a growing public health concern, particularly when used via non-oral routes of administration. However, the role of non-oral routes of administration for RxStim NMU in the larger substance abuse pathway is less well studied. The purpose of this study was to characterize RxStim NMU and investigate substance use trajectories among adults who reported non-oral RxStim NMU recruited from Reddit.

Eligible participants must have been located in the US, English speaking, age 18 y, and have reported RxStim NMU via a non-oral route (any route other than ingestion) within the past 5 y. Participants were recruited from Feb-Sep 2019 using banner ads on Reddit, the 5th most visited website in the US. Participants completed an online survey which captured demographics, lifetime RxStim NMU and illicit substance use; they were compensated for their time. For purposes of this study, NMU included ANY of the following: (1) use for any reason, even once, without their own prescription, (2) use in ways other than prescribed, and (3) use for the feeling or experience the medication caused.

Respondents (n=225) were primarily male (86.2%), 18–24 (48.0%) or 25–34 (43.1%) years of age, and Caucasian (78.2%), Black (7.1%) or Hispanic (5.3%). Lifetime diagnosis of ADHD was reported by 27.6%, with 53.2% diagnosed at age 11–19 and 35.5% at age 20+ years. RxStim NMU via snorting was reported by 99.1%, smoking 3.6% and injecting 6.2% (multiple routes could be reported). Almost all (n=222; 98.7%) also reported lifetime illicit drug use, among whom 182 (82.0%) initiated substance use by using an illicit drug (77.9% marijuana, 1.8% cocaine/crack, 0.9% inhalants, 0.9% hallucinogens, 0.5% methamphetamine/amphetamines) prior to RxStim NMU. Forty (18.0%) respondents initiated with RxStim NMU; 14.4% then initiated marijuana use, 0.9% initiated cocaine/crack use, 0.9% initiated barbiturate use, and 0.5% initiated heroin, inhalant, methamphetamine/amphetamine, and hallucinogen use. Average age of initial RxStim NMU was 18.7 (SD 3.7) years and most often was via swallowing (89.1%) followed by snorting (10.9%). Respondents began using marijuana at age 15.9 (SD 2.5), cocaine or crack at 19.7 (SD 3.3), and heroin at 20.9 (SD 5.5).

Engagement in RxStim NMU via a non-oral route of administration is most often preceded by marijuana use. Among this Reddit-recruited population of non-oral RxStim nonmedical users, only 1 in 4 reported an ADHD diagnosis and <1 in 5 reported RxStim NMU as their first substance use experience; most of these then added marijuana and few moved toward cocaine/crack or methamphetamine. RxStim NMU via non-oral routes is associated with a larger pattern of risky substance use behaviors. Nearly all non-oral RxStim NMU is associated with concomitant drug use, especially marijuana.

Funding. Arbor Pharmaceuticals, LLC