Drug prohibition has dramatically affected countries worldwide. It fuels violence and corruption in Latin America, and Central and Southeast Asia, and is a major contributing factor behind the United States having the highest rate of incarceration in the world. Yet there is scant evidence that prohibition reduces drug use. Despite this lack of evidence, prohibition is the preferred policy stance of governments worldwide. One of the primary justifications of prohibition is that drug use causes individuals’ harm. While there is evidence of individual harms associated with drug use there is also a literature suggesting it is possible to use drugs functionally – defined here as use with minimal impairment to mental and physical health, and social roles and expectations. However, drug use is a politically charged topic and as such little research on functional drug use has come to prominence. The existence of persons who use drugs functionally would allow us to consider alternative approaches to drug control that address the harms that stem from both prohibition and individual use.In this dissertation I conducted three independent but related studies to explore the existence and drivers of functional drug use. In Chapter 1 I systematically reviewed peer-reviewed literature from Ovid MEDLINE, PsycINFO, Scopus, and Web of Knowledge databases regarding functional drug use and find robust evidence that all illegal drugs can be used functionally. Drawing on the narratives of participants across the studies the typical person who uses drugs functionally is marked by three characteristics. First, they actively avoid addiction and take steps to maintain overall good physical and mental health. Second, they are socially integrated with lives that do not revolve solely around procuring and consuming drugs; hallmarks of this included holding a job, attending school, and maintaining connections to non-drug using family and friends. Third, persons who use drugs functionally take pains to avoid negative stereotypes attached to persons who use drugs – paying for their drugs with excess income, avoiding other illegal activities and attending to important socially sanctioned activities. In Chapter 2 I used data from the Inner-City Mental Health Study Predicting HIV/AIDS, Club and Other Drug Transitions (IMPACT) study, a cross-sectional dataset of former and current persons who use drugs in New York City selected via random street intercept between 2005 and 2008, to apply the findings of our review to find participants reflective of the phenomenon of functional drug use. Using exploratory latent class analysis on questions regarding drug use behaviors I report different patterns of drug use within the IMPACT sample and regress measures of social functioning on these classes as distal outcomes to assess the functionality of each class. My solution is a 6-class model consisting of the following use patterns: former non-persons who inject drugs (PWID); former PWID; marijuana use; cocaine, crack and marijuana use; low frequency polydrug use; high frequency polydrug use. Among the classes containing persons who use drugs currently, there was a clear pattern of relative functionality based on the probability of drug related interference and having an illegal main source of income. From most functional to least functional these were: marijuana use (2% interfering use; 5% illegal main source of income), cocaine, crack and marijuana use (48%; 31%), low frequency polydrug use (58%; 38%), and high frequency polydrug use (80%; 57%); compared to 37% of the overall sample reporting interfering use and 24% reporting having an illegal main source of income. Comparing the classes to former non-PWID, marijuana use had a lower odds of drug use interference (OR = 0.07, p-value < 0.01) whereas all other classes had significantly increased odds of drug use interference with increasing odds from former PWID (OR = 1.80, p-value = 0.04), cocaine, crack and marijuana use (OR = 4.46, p-value < 0.01), low frequency polydrug use (OR = 6.48, p-value < 0.01), and high frequency polydrug use (OR = 18.66, p-value < 0.01). Regarding main source of income there was no significant difference between the marijuana use class with the former non-PWID (OR = 0.88, p-value = 0.81). The other classes however, followed a similar step-wise pattern as for drug use interference: former PWID (OR = 2.68, p-value = 0.04), cocaine, crack and marijuana use (OR = 7.21, p-value < 0.01), low frequency polydrug use (OR = 10.08, p-value < 0.01), and high frequency polydrug use (OR = 21.30, p-value < 0.01). In Chapter 3 I built on the results from Chapter 2 to test whether childhood physical abuse, sexual abuse, and neglect (CAN) was associated with membership in less compared with more functional drug use classes using multinomial logistic regression. This analysis builds on literature summarized in Chapter 1 suggesting non-functional drug use is associated with feelings of negative affect and a large body of work documenting associations between CAN and psychiatric and behavioral disorders generally, and drug use specifically. I report that childhood neglect is not associated with different patterns of drug use behaviors but is positively associated with having an illegal main source of income (OR = 1.40, 95%CI 1.02, 1.92). Participants experiencing physical abuse were 1.65 (95% CI 1.06-2.59) times more likely to engage in high frequency polydrug use compared to marijuana use but had no association with drug use interference after adjustment for drug use class. There were positive associations between all measures of sexual abuse with drug use interference and having an illegal main source of income. Adjustment for drug use class accounted for the association with drug use interference but not having an illegal main source of income. This exploration of functional drug use found a strong evidence base of qualitative work supporting its existence; however, there are few extant quantitative investigations. Applying the results of our review to an epidemiologic sample I found a hierarchy of functionality related to different patterns of drug use. Moving this body of work forward requires the development of new scales to measure functional drug use to more fully characterize the phenomenon. Replication across samples will generate much needed estimates of the prevalence of functional and non-functional drug use, key data for drug policy debates. These scales should take into account the three key dimensions outlined by participants across the studies reviewed and be applicable across various kinds of drugs and meaningful cross-culturally. I report evidence supporting an association between CAN with different patterns of drug use and reduced social functioning. Future analyses should measure other sources of childhood trauma if they are interested in the direct effect of CAN on drug use, as well as modifiers of the CAN-drug use relationship to fully characterize the phenomenon. However, it should also be noted that the model this analysis is based on, like most extant theories of use, is rooted in the moral panic over drugs that has engulfed the United States for the last 100 years. These models treat drug use as unequivocally harmful, hence an irrational activity and therefore, implicitly, the result of some trauma. Functional drug use subverts this paradigm and considers multiple reasons for and patterns of use. While there are likely negative inducements towards less functional patterns of drug use we would do well to update our models by considering pleasure and incorporating both positive and negative inducements. New models should then be tested systematically across samples.

Electronic nicotine delivery systems emerged during the 2010s as a novel way to consume (i.e., vape) nicotine. Public health authorities became concerned that vaping could cause nicotine-naïve youth to begin using tobacco products and that a new generation of youth could become tobacco-dependent. Though millions of youth have vaped, authorities' fears about a new generation of youth tobacco dependence has not materialized. A more recent concern is nicotine vaping’s potential effects on cannabis use and the use of other substances. An increase in cannabis use among some adolescent groups and young adults could be because of nicotine vaping’s rise. Additionally, cannabis can be vaped, so transitioning from nicotine vaping to cannabis vaping may be easier than transitioning from nicotine vaping to other forms of cannabis use. Furthermore, nicotine product use was historically associated with later use of cannabis and other substances; this trend may be renewed with the advent of nicotine vaping. To date, most studies on the associations between nicotine vaping and cannabis/other substance use are cross-sectional, so more longitudinal evidence is needed. If evidence suggests that nicotine vaping does affect the use of cannabis and other substances, specifying a mechanism would help with developing potential interventions and with testing the validity of total effects. The overarching goal of this dissertation is to advance evidence of nicotine vaping's potential harmful effects on youth and young adults, which could be used to support interventions aimed at reducing the burden of nicotine vaping's outcomes. First, I conducted a systematic review in which I examined the extent to which confounding, measurement errors, and loss to follow-up could alternatively explain reported longitudinal effects of nicotine vaping on cannabis use or other substance use. I also identified studies that tested effect modification and mediation. This systematic review revealed that nicotine vaping likely increases the risk of subsequent cannabis use and other substance use for up to 24 months. It also revealed that some studies evaluated effect measure modification, while no study assessed mechanisms. These observations suggest that future studies should assess long-term effects on initiation and evaluate potential mechanisms. Second, I evaluated whether nicotine vaping affected the initiation of cannabis and other substances over a six-year period among adolescents as they age into adulthood. Results suggested that nicotine vaping had harmful effects on both outcomes over the six-year period. I also found evidence that nicotine vaping's harmful effects in later years appeared stronger than in earlier years; the absence of age effects suggest the absence of cohort effects. Furthermore, I found that effects appeared stronger among individuals who had a history of non-vaping tobacco product use than among individuals without a history of non-vaping tobacco product use, suggesting that tobacco use is key to nicotine vaping's harms. Finally, I evaluated possible mechanisms of the effects based on a theory that I developed from prior empirical literature and behavioral theory. I posited that nicotine vaping caused deviant peer affiliation, which caused conduct problems and subsequently, the outcomes. I found no evidence that three conduct problems (considered together) were mechanisms of the effects. Future studies of mechanisms can reveal potential intervention targets, lead to studies of other potential mechanisms, and help test the validity of total effects. This dissertation achieved its goal of advancing evidence that nicotine vaping may harm youth and young adults. Public health bodies tasked with addressing potential public health concerns about nicotine vaping products should consider evidence from this dissertation.

This dissertation explores the potential of documentary films to impact the discourse around a public health issue and in particular the current opioid epidemic. In addition to reviewing the history of drug policy and drug epidemics, this dissertation analyzed an HBO documentary about the opioid epidemic as a means of contextualizing the current crisis and understanding whether documentary can change the narrative around a public health matter. A systematic review of the literature was conducted to evaluate the existing published evaluation studies relating to the potential role of documentary films to influence the levers of discourse related to the opioid epidemic and related substance use and mental health disorders and found the existing research was limited to fifty-four citations. Documentaries can have a potential impact on public discourse most notably through raising public awareness but the impact is limited as drug use epidemics are complex and multifactorial. Further study is needed to fully understand the role that documentary films can play in shaping public discourse.

Background: Despite substantial global progress against the HIV/AIDS epidemic, the Eastern Europe and Central Asian region has experienced a 43% increase in HIV incidence. The HIV epidemic in Kazakhstan has outpaced that of the region, with the incidence of new infections growing by 73% since 2010. Key populations of people who inject drugs (PWID), female sex workers (FSW) and their sexual partners account for the majority of new infections, where drug policies continue to undermine HIV prevention and control efforts. Kazakhstan has made insufficient progress towards 95-95-95 HIV epidemic control targets, with 78% of people living with HIV (PLWH) knowing their HIV status, of which 57% receive ART, and 48% of those receiving ART achieve viral suppression. Laws, policies and their enforcement can shape social and structural determinants of health, and it is fundamental to understand how punitive legal environments shape the HIV epidemic in Kazakhstan. This dissertation seeks to identify patterns of police violence victimization among FSW who use drugs and examine how police violence is associated with the HIV risk environment. Given the insufficient progress towards 95-95-95 HIV epidemic control targets, this dissertation also seeks to identify how patterns of injection and sexual HIV transmission risk behaviors vary among men and women who inject drugs and examine how criminal-legal involvement is associated with patterns of HIV transmission risk behaviors. Methods: Data on police violence victimization among FSW who use drugs were drawn from Project Nova, a cluster-randomized control trial that evaluated the efficacy of a combination HIV risk reduction and microfinance intervention. A community-based sample of 255 FSW who use drugs were recruited and enrolled between February 2015 and May 2017 in Almaty, Kazakhstan. Latent class analysis (LCA) was used to characterize women into distinct subgroups (i.e., classes) of police violence victimization. Next, multinomial logistic regression was used to examine how police violence victimization subgroups are associated with the physical, social, economic and policy HIV risk environment. Data on injection and sexual HIV transmission risk behaviors were drawn from Bridge, an implementation science study that evaluated the effectiveness of HIV service integration into needle/syringe programs on retention in care and viral suppression for PWID living with HIV in Kazakhstan. A random sample of 450 men and 166 women who inject drugs were recruited and enrolled in Almaty, Shymkent, and Temirtau/ Karaganda between February 2017 and June 2019. Similarly, LCA was used to characterize distinct subgroups of HIV transmission risk behaviors among men and women who inject drugs. Multinomial logistic regression was then used to identify associations between criminal-legal involvement and patterns of HIV transmission risk. Results: Three subgroups of police violence victimization among FSW who use drugs emerged. Just over half were characterized as experiencing low violence victimization (“Low Violence;” 51%); over one-third were characterized as experiencing all forms of police violence victimization (Poly-Victimization; 34%), and 15% were characterized as experiencing primarily discrimination and extortion from the police. Relative to Low Violence, factors associated with Poly-Victimization included being positive for HIV and/or sexually-transmitted infections (STI) (aOR= 1.78 (95% CI: 1.01, 3.14)), prior tuberculosis diagnosis (aOR= 2.73 (1.15, 6.50)), injection drug use (IDU) (aOR= 2.00 (1.12, 3.58)), greater number of unsafe injection behaviors (aOR= 1.21 (1.08, 1.35)), homelessness (aOR= 1.92 (1.06, 3.48)), greater drug use stigma (aOR= 1.22 (1.07, 1.39)) and sex work stigma (aOR= 1.23 (1.06, 1.43)), greater number of sex work clients (aOR= 2.40 (1.33, 4.31)), working for a boss/pimp (aOR= 2.74 (1.16, 6.50)), client violence (aOR= 2.99 (1.65, 5.42)), economic incentives for condomless sex (aOR= 2.77 (1.42, 5.41)), accessing needle/syringe exchange programs (aOR= 3.47 (1.42, 8.50)), recent arrest (aOR= 2.99 (1.36, 6.55)) and detention (aOR= 2.93 (1.62, 5.30)), and negative police perceptions (aOR= 8.28 (4.20, 16.3)). Compared to Low Violence, Discrimination and Extortion was associated with lower odds of experiencing intimate partner violence (aOR= 0.26 (0.12, 0.59)), but no other significant associations with the risk environment upon adjusting for socio-demographic characteristics. Distinct patterns of HIV transmission risk behaviors emerged among men and women, in which men were characterized as having Low Sexual Risk (41.8%), Injection & Sexual Risk (36.4%), and High Injection Risk (21.8%) behaviors. Class membership in the Injection & Sexual Risk and High Injection Risk class was associated with greater criminal-legal involvement, compared to the Low Sexual Risk class. This is demonstrated by higher odds of multiple detentions ((aORInjection & Sexual Risk = 1.28 (1.10, 1.49); aORHigh Injection Risk = 1.25 (1.06, 1.46)) and drug court participation (aORHigh Injection Risk = 5.29 (1.03, 27.20) in the past six months, committing crimes while under the influence of alcohol or drugs (aORInjection & Sexual Risk = 2.79 (1.53, 5.11); aORHigh Injection Risk = 2.76 (1.34, 5.65), and perceived police discrimination (aORHigh Injection Risk = 1.79 (1.01, 3.19). Women who inject drugs were characterized as having Low Injection & Sexual Risk (60.7%), Sex Work Behaviors (8.4%), High Injection Risk (30.7%) behaviors. Class membership in the Sex Work Behaviors and High Injection Risk class was associated with greater odds of being detained (aORSex Work Behaviors= 4.59 (1.27, 16.53) and experiencing verbal police harassment (aORSex Work Behaviors= 3.31 (1.20, 9.15); aORHigh Injection Risk = 2.91 (1.32, 6.40), compared to the Low Injection & Sexual Risk class. Conclusion: Results from this dissertation show that police violence against FSW who use drugs is pervasive in Kazakhstan. Patterns of police violence victimization among FSW who use drugs vary, with multiple forms of police violence victimization being associated with greater HIV susceptibility. This dissertation also demonstrates that men and women who inject drugs and are living with HIV have a high prevalence of injection and sexual HIV transmission risk behaviors, despite low viral suppression, and that patterns of HIV transmission risk behaviors vary by gender. Moreover, criminal-legal involvement is associated with injection and sexual HIV transmission risk, particularly among men who inject drugs. Collectively, these results support drug policy reforms and suggest that decriminalization of drug use and possession may promote enabling environments that support harm reduction, and subsequently reduce HIV transmission through injection and sexual networks of PWID in Kazakhstan.