Phase B

Background. The reasons for initiation and continuation of use of illicit substances are multifactorial; however, some individuals appear resistant to both. One set of determinants lies in the environment. In ongoing studies, we are examining environmental concomitants of behavior in individuals in drug treatment. In this study, we will examine environmental factors that may impact initiation, addiction, and treatment seeking among the greater population at large (nondrug-users, current opioid/stimulant users, and current marijuana users).

Scientific goals. (1) To assess, cross-sectionally at baseline, differences in stress, social stability, and mental and physical health among three main neighborhood-matched groups of current opioid/stimulant users, current marijuana users, and nondrug users; (2) to assess, longitudinally, mediators of 12-month changes in drug-misuse status in the same three groups; (3) to provide neighborhood-matched control groups of non-drug-using individuals, Unclassified/former drug users, and current opioid/stimulant drug users not seeking treatment for our ongoing environmental studies of individuals in drug treatment; (4) to explore the possible role of genetics and its interplay with environment in regards to drug use initiation, addiction, and treatment seeking among the study groups, (5) to assess EMA reports of drug use and psychosocial stress as well as real-time environmental risk exposure in a non-treatment seeking and/or nondrug using population and compare to our ongoing environmental studies of individuals in drug treatment, (6) to assess the accuracy of stress detection in the lab and the field by the Health Tag.

Participant population. We will enroll 650 participants in Phase B of the study for a total enrollment (Phase A + Phase B + Phase C) of 3000 participants. Target enrollment will include 25% women and 70% minorities (mostly African American).

Experimental design and methods. This is a three-group observational study with a crosssectional component and a longitudinal component: each participant will be assessed in two visits spaced approximately 12 months apart. For participants enrolled in Phase B after January 26, 2021, the interval between the two visits may be shorter than 12 months. The three main groups will be: (1) non-drug-users (NDUs), (2) current opioid/stimulant users \[(COSUs) comprised of two subgroups: treatment seeking (COSU-TS) and non treatment seeking (COSU-NTS)\], and current marijuana users (CMUs). All groups will be roughly matched for socioeconomic status and neighborhoods of residence. Each participant will attend a 3-5-hour initial study visit and a 3-5-hour 12 month visit #2. The study visits will include a questionnaire component and a biologicalsample component. Questionnaires will cover substance use, stress, social stability (including healthcare access/utilization, and neighborhood environment), physical and mental health (including quality of life, HIV, and trauma). The biological component will consist of samples of urine (for drugs of abuse and cotinine), breath (for alcohol and carbon monoxide). Blood for genetics will be obtained at Visit 1 or Visit 2. The primary outcome measures will be lifetime substance-misuse history (cross-sectional component) and changes in drug-use status across the 12 months between visits (longitudinal component). Secondary outcome measures will include: biological assessments of drug use; medical, psychiatric, social determinants of health; and impulsivity and decision-making factors. Individuals who choose not to return for a 12-month Visit #2 will be asked to complete a 45-minute telephone visit #2. For participants enrolled in Phase B after January 26, 2021, all participants will be asked to complete their visit #2 by telephone only. In the HON EMA/GMA secondary study participants will carry a smartphone for up to 4 weeks after completing Visit 1. Event-triggered entries will be initiated by participants (1) each time that they use a drug (COSU) or marijuana and/or alcohol (NDU, CMU, and Unclassified) and (2) each time they feel overwhelmed, anxious, or stressed more than usual. Participants will also make 5 random-signal-triggered recordings per day and one brief end of day recording. During this study participants will also complete compliance visits once per week. In the Health Tag secondary study, participants will undergo a one-day laboratory session followed by a 30-day field study. Benefits to participants and/or society. There are no benefits to participants. The knowledge gained may benefit society by providing data on the health outcomes of drug-using and non-drugusing individuals and the natural history of drug use by neighborhood.

Risks to participants. This is a minimal-risk study, consisting of standard physical and questionnaire-based assessments.