Transitions from first drug use to illicit opioid and injection drug use in a multisite rural U.S. cohort of people who use drugs

AIM: To understand circumstances surrounding transitions between initial drug use, non-prescribed opioid use, and injection drug use (IDU) among people who use non-prescribed opioids in the rural U.S. METHODS: We interviewed adults who use non-prescribed opioids in 10 states. We coded transcript data regarding age, drug, modality, circumstances for each "first use" event and transitions to illicit opioid use/IDU. Transition-related themes were categorized using the Social Ecological Model (SEM) through iterative qualitative memoing. We calculated frequencies and measures of central tendency. RESULTS: Participants (n = 304, mean age [MA] = 36 years, 56% male) reported marijuana or opioid pills as first drug used (60%, reported MA = 13, and 16%, MA = 19, respectively). First opioid use (MA = 20) was typically pills (74%); 43% were initially prescribed opioids for pain. Of participants reporting IDU (92%, MA = 24), first drugs injected were methamphetamine (26%), opioid pills (22%), and heroin (22%). Reasons for first injection of these three substances were recreational (65%, 84%, 66%, respectively) followed by mental health coping (35%, 16%, 33%). Interviews revealed factors influencing transition to illicit opioid use/IDU at environmental, interpersonal, and intrapersonal levels of the SEM, including early household exposure to drugs, and family/peer encouragement to use opioids for coping. Participants described initial use of prescribed opioids following surgery or workplace injury, followed by illicit use of opioids and later IDU for recreational as well as practical goals. IDU was facilitated by intimate partners and friends in the context of diminished local access to illicit opioid pills. CONCLUSION: Among people who use opioids and inject drugs in the rural U.S., drug use typically started in pre-adolescence, first opioid use in early adulthood, and IDU a few years later, highlighting the need for early intervention. Methamphetamine comprised a substantial proportion of initial IDU raising concerns for polysubstance use. Drug use for coping highlights the need for increased mental health resources in rural areas.