PERCEPTIONS OF PROSPECTIVE PHARMACEUTICAL STIMULANT SUBSTITUTION TREATMENTS AMONG PEOPLE WHO USE ILLICIT STIMULANTS IN VANCOUVER, CANADA

Abstract

Background

Stimulant-involved overdose deaths are increasing, driven by polysubstance use and adulteration of the illicit drug supply. While emerging evidence for prescription stimulant substitution is promising, there are no approved treatment options for stimulant use disorder that address the realities of an unpredictable drug supply. This study explores treatment experiences of people who use illicit stimulants (PWUS) to identify gaps and perceptions of prospective pharmaceutical stimulant substitution treatments (SST).

Methods

In-depth qualitative interviews were conducted with 86 PWUS in Vancouver, Canada. Thematic analysis focused on experiences of available treatment options for stimulant use and perceptions of prospective SST.

Results

Participants identified how primarily behavioral treatment approaches do not meet the unique needs of PWUS, in contrast with the range of medical treatments available for opioid use disorder. Participants anticipated health and social benefits if they were able to access SST, including avoiding the toxic illicit stimulant supply, reduced engagement in criminalized activities, and greater economic security. Perceptions of prospective SST were informed by knowledge of existing opioid treatments. This led some participants to be unsupportive of SST, citing concerns around agency and highly regulated operational contexts that do not align with the lived realities of stimulant use.

Conclusion

Findings demonstrate the need for SST pilot programs in real-world settings and underscore the health and social advantages SST may offer; although drawing on existing opioid treatment models to implement SST pilots may limit success. Thus, any novel treatments for stimulant use must centre the lived realities of PWUS.

INTRODUCTION

Illicit stimulant use has been steadily rising across the globe, and with it, associated harms (e.g., psychosis, cardiovascular dysfunction, overdose) (Ahmad et al., 2023; Farrell et al., 2019; Jones et al., 2022). Stimulant-involved overdose deaths are increasing, and in some North American jurisdictions are on par with that of opioid-involved overdose deaths (DiGennaro et al., 2021). Epidemiological data suggest this is driven by polysubstance use and adulteration in the illicit drug supply, with most stimulant-involved deaths also involving opioids—most commonly, fentanyl (DiGennaro et al., 2021; Hoopsick & Yockey, 2023). The rising rates of stimulant-involved overdose have been most stark among racialized groups. Methamphetamine and opioid co-involved overdose among Black Americans increased by almost five times as much as white Americans from 2007 to 2019, while Indigenous people (commonly coded as American Indian/Alaska Native in American overdose surveillance data) consistently experience the highest stimulant-involved overdose mortality rate among racial and ethnic groups regardless of opioid co-involvement (Kariisa et al., 2021; Townsend et al., 2022). Similar disaggregated data by drug type is not available in Canada. However, given the overall overdose mortality rate is five times higher among Indigenous people than non-Indigenous people, similar racial differences with regards to stimulant-involved overdose are likely (First Nations Health Authority, 2023).

Fentanyl and related analogues, which are driving North America’s overdose crisis and now dominate the illicit opioid market, are increasingly being detected in street-level stimulant supplies along with other adulterants (Daniulaityte et al., 2023; DiGennaro et al., 2021), although there is regional variation in this trend. Canadian drug seizure and surveillance data indicate that fentanyl and related analogues were detected in illicit stimulant supplies up to 10 times more frequently in Western than Eastern provinces (Payer et al., 2020). Similar US data reports that fentanyl-adulterated stimulants are more often found in Northeastern and Midwestern states (Daniulaityte et al., 2023; Park et al., 2021), though we anticipate this data to soon reflect the westward expansion of fentanyl in the US and qualitative reports of increasing experience with fentanyl-adulterated stimulants in Western states (Ciccarone, 2021; Shin et al., 2022). This is further substantiated in recent qualitative research finding that people who use stimulants (PWUS) perceived themselves to be at heightened risk of overdose due to fentanyl-adulterated stimulants since the outset of the COVID-19 pandemic (McNeil et al., 2022). While public health responses to the overdose crisis have directed more attention to opioid-focused interventions, these both remain inadequate and insufficient to fully address drug-related harms amidst rising polysubstance use and fentanyl adulteration. There is an urgent need for solutions that account for the risks of an increasingly potent and unpredictable illicit stimulant supply.

Treatment options for stimulant use disorder (SUD) are generally limited to psychosocial interventions promoting sustained abstinence (e.g., twelve-step facilitation, contingency management) (Farrell et al., 2019; Fischer et al., 2015; Ronsley et al., 2020). Evidence suggests these approaches have limited effectiveness and do not address instrumental uses of illicit stimulants (e.g., energy, productivity) (Benishek et al., 2014; Farrell et al., 2019; United Nations Office on Drugs and Crime, 2019). Moreover, PWUS have characterized available treatment services as opioid-centric, reporting low confidence in the suitability and effectiveness of treatments not specific to stimulant use (Cumming et al., 2016). There are currently no approved pharmacotherapies for stimulant use, which is especially notable considering it has been 30 years since heroin-assisted treatment first emerged in Switzerland to provide a pharmaceutical alternative to illicit opioid use (Rehm et al., 2005). Furthermore, there have been modest efforts to expand opioid pharmacotherapies (e.g., injectable hydromorphone, prescribed safer supply options) in recent years which have led to an abundance of research evidencing these interventions (Glegg et al., 2022) without similar attention to illicit stimulants.

Stimulant substitution treatment (SST), in which PWUS receive prescription psychostimulants (e.g. dextroamphetamine, methylphenidate) as a substitute to an illicit counterpart, is thought to have potential in addressing the harms of illicit stimulant use as they share similar pharmacological effects, although results from trials are mixed (Ronsley et al., 2020; Tardelli et al., 2023). For example, some small-scale randomized clinical trials have evidenced sustained-release methylphenidate as an effective substitute for methamphetamine (Longo et al., 2010; Rezaei et al., 2015), while others found no difference between treatment and placebo groups (Ling et al., 2014; Miles et al., 2013). Outcome measures in these trials include self-reported methamphetamine use, treatment retention, and drug screening results (e.g., hair or urinary testing). Miles et al. (2013) note that their results were confounded by low retention rates and suggest that medication dosages and strict trial requirements (e.g., daily supervised dosing) may have been incompatible with participants’ lived realities in ways that limited treatment engagement. This provides context for understanding Ronsley et al.’s (2020) findings in their recent systematic review that there is not yet enough evidence to support or discount SST, but that overall results are promising. Further calls for more pragmatic SST trials highlight how evaluating effectiveness via sustained abstinence may obscure findings, suggesting alternative outcome measures (e.g., reduced illicit stimulant use, self-reported treatment satisfaction) that are more appropriate, particularly for marginalized populations (Fleming et al., 2020; Palis et al., 2021). Given the critical need for effective pharmacological treatments for SUD, research investigating the SST needs of people who use illicit stimulants is needed to optimize implementation of future SST programming.

High attrition, narrow operational definitions of treatment efficacy, and operational contexts that are incompatible with the lived realities of PWUS observed among SST trials highlight a significant gap in the literature with regards to the perspectives of PWUS. This study aims to identify treatment needs of people who use illicit stimulants and perceptions of prospective pharmaceutical SSTs. In doing so, we highlight how current approaches for treating SUD do not attend to the unique needs of structurally vulnerable PWUS. We then articulate how PWUS envision prospective SST working (or not) within the bounds of their lived experiences and treatment needs. Rather than making a case for any specific candidate medication or treatment model, this study considers how SST as a concept may operate within a context of widespread socioeconomic marginalization.

METHODS

This study draws on semi-structured qualitative interviews conducted as part of a larger study exploring experiences of illicit stimulant use among structurally vulnerable people who use drugs (Ivsins et al., 2022; Mansoor et al., 2022). 86 PWUS were interviewed between January 2019 and March 2020, when data collection was suspended due to the onset of the COVID-19 pandemic. Participants were recruited via community outreach activities and two ongoing prospective cohort studies of people who use drugs in Vancouver, the At-Risk Youth Study (ARYS; 14–24 years of age and illicit drug use in past month at enrollment) and the Vancouver Drug Users Study (V-DUS; ≥18 year of age and illicit drug use in past month at enrollment), which have been described in detail elsewhere (Wood et al., 2006). The V-DUS cohort’s demographics skew older, with most cohort participants being of white ethnicity and male (Moallef et al., 2019). Further, longstanding cohort studies may disproportionately exclude individuals who experience a greater degree of vulnerability, including those who are unstably housed and are poorly connected to support services (Parashar, 2016). These complimentary recruitment tactics were thus necessary to achieve a more diverse sample with respect to age, gender, and ethnicity. Cohort participants reporting recent (past 30 days) illicit stimulant use at their most recent follow up survey were eligible to take part in the present study, and were recruited and scheduled for interviews by cohort study staff. Community recruitment activities were conducted by peer researchers, who invited individuals to participate in the present study if they self-reported frequent illicit stimulant use.

Participants were interviewed at storefront research offices in Vancouver, British Columbia’s Downtown Eastside (V-DUS and community-recruited participants) and Downtown South (ARYS participants) neighborhoods. Recruitment and interviews for this study occurred in three waves. First, in the Downtown Eastside with V-DUS, then community-recruited participants, and lastly with a youth-focused wave comprised of ARYS participants. Participants provided written informed consent prior to their interview and received $30 (CAD) as compensation for their time. An interview guide was used to facilitate discussion and included questions related to drug use practices, treatment experiences and needs, and perceptions of SST. As a concept, SST was explained to participants with dextroamphetamine and methylphenidate as examples. Interviews were audio-recorded and transcribed verbatim.

Transcripts were imported into NVivo 12, a qualitative data management and analysis software. We used a collaborative team approach in developing a coding framework based on initial reviews of a selection of transcripts, observations from interviews, and on a priori themes informed by topics in the interview guide (Creswell & Creswell, 2017). The coding framework was revised throughout analysis as needed at subsequent meetings to reflect emerging themes and categories. Transcripts were coded by two team members each to support interrater reliability, and coding disagreements were resolved via group consensus during team meetings. The present analysis draws on all interview data (n = 86), with thematic analysis focusing on perspectives of current treatment options and prospective pharmacotherapies. See Table 1 for participant characteristics. This study received ethical approval through the University of British Columbia/Providence Health Care Research Ethics Board.

Table 1.

Participant characteristics.

	n = 86
Age
Mean	42.7
Range	21–65
Gender
Men	36 (42 %)
Women	48 (56 %)
Transgender, Two-Spirita, or non-binary	2 (2 %)
Ethnicity
White	38 (44 %)
Indigenous	40 (47 %)
Other	8 (9 %)
Drug of choice
Heroin/fentanyl	9 (10 %)
Crack cocaine	24 (28 %)
Crystal methamphetamine	22 (26 %)
Goofballsb	16 (19 %)
Other	15 (17 %)
Drug use pattern
Stimulants only	33 (38 %)
Stimulants and other drug types	53 (62 %)
Frequency of drug use
Daily	61 (71 %)
3–4 times per week	12 (14 %)
≦1 time per week	13 (15 %)
Methods to consume drugs *
Inject	38 (44 %)
Smoke/inhale	60 (70 %)
Snort	15 (17 %)
Ingest/swallow	5 (6 %)

^aTwo Spirit refers to Indigenous persons with masculine and feminine spirits (Lyons et al., 2016)

^bGoofballs refers to heroin/fentanyl and methamphetamine co-injection

^*Participants could select more than one option

RESULTS

The highest proportion of participants identified as Indigenous (47 %), and most also identified as women (56 %). Stimulants were the predominant drug of choice, with 28 % of participants reporting crack cocaine and 26 % reporting crystal methamphetamine as their drug of choice. Opioid-methamphetamine polydrug use (i.e., “gooaballs”) was the drug of choice for 19 % of participants. Of our sample, 62 % reported using other drugs in addition to stimulants with the remainder (38 %) reporting stimulant use only. We did not observe different patterns regarding perceptions of SST based on drug of choice or use patterns.

Unmet treatment needs

Participant narratives challenged perceptions of PWUS as treatment resistant, instead framing current treatment options as inadequate in meeting their needs. Treatment for SUD was commonly understood as entering residential treatment and seeking abstinence, although participants considered these spaces to be largely inaccessible to PWUS due to prioritization of opioid use within the context of the fentanyl-driven overdose crisis. One participant who had experience with a range of residential, outpatient, detox, and psychosocial treatment settings was unaware of any stimulant-specific treatments, noting that in her experience treatment programming was intended to address “all drug use, but not really stimulants. Not really crystal meth. It’s usually talking about heroin, pills, morphine or something like that” (33-year-old Indigenous woman). This compliments another participant’s experience of residential treatment: “It’s not a place for meth users, it’s just not” (57-year-old white man). Participants also described how the predominantly psychosocial treatment interventions available to them as PWUS were in tension with their experiences of structural oppression:

Some people I’m just like, ‘you have basic bitch problems, you don’t deal with what we [PWUS] deal with.’ I sat in a group therapy one time and this woman kept talking about how her boyfriend would not buy her the right makeup or buy her certain flowers and stuff like that and it was like, ‘what the fuck are you doing here?’ I was just sitting there getting really angry and then she got mad because her dad cut off her credit card and stuff like that and like, boo hoo, I can’t even afford dinner tonight. (27-year-old Indigenous non-binary person)

This participant’s experience further illustrates how available treatment options for PWUS can be experienced as isolating and irrelevant, particularly against broader contexts of marginalization.

This underscores how limited the treatment options for stimulant use are perceived to be, leading participants to view stimulant use as left out of harm reduction and treatment discourses: “Side guys [methamphetamine users] need some kind of an option other than just no help” (62-year-old white man). While there are a range of medical treatments for opioid use and emerging prescribed safer supply options, participants positioned the lack of similar and accessible options for stimulant use as exemplifying an overarching stigma against PWUS, particularly given the increasing risk of mortality from the illicit drug supply: “Anytime that people talk about safe supply they leave out stimulant users and it’s frustrating cause we’re dying too, but I guess you don’t care about us” (27-year-old Indigenous non-binary person). Moreover, participants discussed instrumental reasons for stimulant use (e.g., wakefulness, untreated pain, reducing risks of violence or victimization) not accounted for within prevailing abstinence-centered frameworks, suggesting the need for interventions that address these necessities:

I’m at that age where I’ve got pain issues and I’ve resigned myself to be on some sort of a narcotic pain reliever for the rest of my life… When I do speed, it lifts and elevates my mood and how I feel about things, and, you know, things look brighter. (63-year-old white man)

Other participants similarly discussed pain-relieving and energizing effects of their stimulant use, and therefore were not interested in pursuing treatment if these needs remained unaddressed. The same participant also described how wider contexts of vulnerability—in his case, substandard housing, poverty, HIV diagnosis, and untreated chronic pain—framed his drug use patterns. He noted that his drug use increased during the times he felt more acutely aware of his circumstances, implying the mental health benefits from his earlier quote:

I would say free time [is when I use the most], you know, and like my situation, as I said, is far from perfect. And so in the evenings I Hind are the toughest times for me because I sit there and I think about things, and it’s not quite depression but it’s not like, oh, joy, right? (63-year-old white man)

This suggests the role of wider experiences of marginalization in shaping instrumental drug use, thus calling attention to the need to address structural drivers of health and social harms.

Indigenous participants highlighted the lack of culturally safe treatment options. This was discussed by one participant, who described how systemic racism embedded within health care fosters an exclusionary environment for Indigenous PWUS seeking treatment supports:

Some [services] are friendly, but most of them, they hire people that are kind of racist. You can sense it when you’re there. They are bugging you to leave, but they’re not bugging the white people to leave, and they came in at the same time as you, so why are you bugging me? (52-year-old Indigenous woman)

Indigenous participants also described cultural practices such as cedar brushing and bead work as “good medicine” when discussing unmet treatment needs, highlighting how cultural practices are not accounted for in the predominantly Western treatment frameworks.

Perceived benefits of SST

There were many perceived direct and indirect benefits to SST. Participants anticipated improvements in health, social, and economic situations if they were able to access this form of treatment. Most obviously, SST could function as a safer supply intervention within the context of the current overdose crisis by enabling participants to reduce reliance on the unpredictable drug supply: “What I need is something where I don’t have to wonder if I’m gonna die from it” (62-year-old white man). Additionally, some participants suggested that a substitution program administered within the medical system would be inherently safe, as health care providers have a moral/professional responsibility to do no harm and thus any supplied pharmaceuticals could be trusted:

I’m pretty sure people will try that. Because you don’t really die from pills you get from a physician, right? ...And you know it’s not cut, and it’s coming through the counter, and it’s supervised. The doses, and the intake, it’s certified, and it’s bracketed out. (23-year-old white man)

Here, the idea that a prescribed pharmaceutical is regulated adds an additional degree of credibility to claims of safety. This may also speak to a more general perception that pharmaceuticals are safer than unpredictable and adulterated street drugs.

Participants also reported that SST would allow them to meet needs addressed by illicit stimulant use (e.g., wakefulness, productivity) outside of a criminalized context and reduce risks associated with drug criminalization (e.g., drug seizure, arrest). As one participant noted, PWUS would “much rather do it legally than illegally, and the stuff we’re getting now, who knows what it is. It’s not what it used to be” (62-year-old white man). This underscores the compounding risks of drug use within a context of both criminalization and an adulterated supply. Beyond illicit stimulant use, SST may mitigate the need to generate income to support drug use through criminalized or stigmatized activities (e.g., shoplifting, sex work): “I will Hind any way to be able to get drugs, whether it’s through sex work or getting money from a friend, borrowing money” (22-year-old white woman). Thus, SST might also reduce ancillary drug-related risks. Relatedly, participants suggested that an effective SST intervention may address poverty and economic insecurity by reducing the need to buy illicit drugs: “I’d love to try something like that and just see if it would work. I’d love to see myself having money all the time” (62-year-old Indigenous woman). Other participants similarly emphasized the significant economic impacts of their drug use, implying that an intervention that responds to the economic vulnerability of PWUS will have a high degree of acceptability and uptake.

Despite earlier admonitions of abstinence-based approaches, some participants expressed a desire to stop using drugs, reporting that the routine and predictability of SST might support them in this endeavor over time. In contrast to past experiences with strict abstinence-based treatments, participants perceived that SST would allow them to exercise greater agency over their drug use, with one Indigenous participant suggesting that reduced reliance on Vancouver’s illicit drug supply would grant her the mobility to meet cultural treatment needs: “I would love to go back to my reserve, its clean air. Maybe visit the Elders and things like that… It’s beautiful. You see eagles, ravens every single time” (47-year-old Indigenous woman). Importantly, the reduced illicit drug use expected by this participant is derived from her conceptualization of SST as allowing take-home doses, highlighting this as an important point to consider for future substitution therapies. Another participant related anticipated reductions in illicit drug use to his economic insecurity:

I actually would like to maybe try that, maybe see about trying to actually finally quit once and for all. Really, you’re just pouring your money away. But like I said, it’s just a way of forgetting the nightmare you’re living every day. (54-year-old white man)

This quote also underscores how SST may not be able to address broader structural vulnerabilities intersecting with illicit drug use (e.g., housing vulnerability, intergenerational trauma, poverty). This participant positioned his stimulant use as a survival strategy within a context of extreme precarity, suggesting that SST’s effectiveness may be limited if implemented absent structural interventions to address the “nightmare” at large.

Perceived drawbacks and barriers

Perceptions of prospective SST were informed by knowledge of existing opioid treatment and safer supply programs, leading some participants to be skeptical of SST. Participant narratives revealed an underlying concern that any prospective SST would not be offered in dosages, schedules, or formulations strong enough to achieve the desired feeling:

They [substitution programs] take the fun out of it, and that’s kind of how it goes. And because of that, I feel all these programs will have a limited amount of success, right? Because people take drugs for fun, for euphoria, right? For altered states. Not to feel normal, unsick [manage withdrawal symptoms], right? (63-year-old white man)

This was particularly acute among participants for whom SST’s appeal was in avoiding the contaminated drug supply, rather than managing withdrawal or reducing stimulant use. Further questions emerged regarding participant agency in trying different medications and dosing regimens to effectively assess comparability and produce the desired feeling. This suggests that any SST program in which the felt effects did not adequately compare to those of the criminalized—and often more potent—counterpart would have poorer acceptability.

Again, drawing on knowledge of existing opioid treatments, participants cited the loss of agency requisite of program participation as a potential deterrent to SST. Participants reported that such programs involve highly regulated operational contexts (e.g., daily witnessed ingestion, routine urine drug screening) misaligned with the lived realities of stimulant use (e.g., sporadic usage, binge use). For example, one participant had previously received an off-label prescription stimulant from a physician willing to prescribe in this way, saying of their experience:

It’s so restrictive because you have to go into the pharmacy every day, literally put your fingers in your mouth, just make sure you swallowed your pill, and then you have to do a pee test every week, too, and if you come back and there’s meth in your system, they cut you off. That’s not the way to do the program. (27-year-old Indigenous non-binary person)

The expectation of strict program requirements and implicit threat of punishment was a common concern among participants, and thus positioned as a significant barrier to SST participation. The above participant later had their prescription cancelled when routine urinalysis revealed they were supplementing their medication with methamphetamine, which they reported as necessary because they were “not on a high enough dose.”

Relatedly, some participants expressed a lack of trust in physicians stemming from past negative experiences with the medical system. For Indigenous participants, these experiences were framed by historical and ongoing colonialization practices that had cascading and devastating effects beyond their medical care. The following participant related her distrust of physicians to her experience with the child welfare system, which disproportionately apprehends Indigenous children (Barker et al., 2014):

We hide it [drug use]. We’re dishonest when we go to the hospital. We don’t go to the hospital. So much stigma. So I think even if there were doctors that you could access that wouldn’t report to the Ministry [of Child and Family Development], as long as the child wasn’t in [danger]. Ones [doctors] that were more sensitive to how that could be communicated to [the Ministry], and once again removing the shame. Because a lot of people won’t ask for help if they’re scared… It’s so easy to lose your kids… We’re [Indigenous people] stereotyped for addictions. (39-year-old Indigenous woman)

This suggests that the perceived risks of disclosing drug use to a physician may be a significant barrier to SST engagement, especially for racialized PWUS. Additional characterizations of physicians as “slimeballs” who “make you jump through their hoops and play games” indicate a reluctance to accept treatment and addiction-related care from untrusted sources, underscoring concerns surrounding preservation of autonomy. This further illustrates how abstinence-oriented prescribing practices implemented within highly regulated contexts may undermine access to SST and other novel pharmacotherapies.

DISCUSSION

In summary, findings demonstrate the need for SST pilot programs in real-world settings and underscore the health and social advantages SST may offer. However, findings suggest that drawing on existing opioid treatment models to implement an SST pilot may limit its success. Thus, findings highlight the need to center the lived realities of PWUS in any novel SUD treatments.

Our findings point to a gap in care resulting from lack of attention to illicit stimulant use within treatment discourses, and a narrow range of treatment options that do not address the realities of illicit stimulant use. This builds on previous research demonstrating negative attitudes concerning treatment relevancy and effectiveness, particularly within prevailing treatment frameworks that either implicitly or explicitly center opioid use (Cumming et al., 2016; Kenny et al., 2011). Our findings suggest that SST could help fill this gap in care, in part by addressing stimulant-related experiences and motivations that cannot be immediately met via abstinence (e.g., energy, productivity, pleasure). Further, while some PWUS seek abstinence from illicit stimulants as a treatment goal, our findings highlight how current treatments are unequipped to support them working towards this within a context of extreme precarity, thus building upon previous work calling for specialized treatment options that are specific to the lived realities of PWUS (Fleming et al., 2020; Ronsley et al., 2020). Relatedly, findings from small-scale pilots distributing pharmaceutical stimulants, including reduced risks of overdose and criminalization, and increased retention in healthcare services (McNeil et al., 2022; Palis et al., 2021), provide further evidence for the health, social, and economic benefits anticipated by our participants. These pilots were both implemented in highly specific contexts (i.e., COVID-19 risk mitigation and within one specific clinic-based injectable opioid agonist treatment program). However, when taken together with our findings, this research suggests that SST may address drug related risks and wider contexts of marginalization. Given this, our findings point to the need to rapidly scale up and evaluate SST interventions to better understand how such interventions operate in real-world contexts.

This study’s findings challenge previous conclusions that SST is not an effective approach for addressing stimulant-related harms by pointing to the need to better align these approaches with the needs of PWUS. Previous SST trials have been abstinence-oriented and modeled after existing opioid pharmacotherapies (Fleming et al., 2020; Ronsley et al., 2020). As such, trials have administered candidate medications in doses and formulations intended only to reduce cravings by providing a consistent level of stimulation throughout the day, rather than to mirror what people seek in the illicit market. However, even within these parameters, a recent meta-analysis found greater treatment retention and reductions in illicit stimulant use with higher dose SST (Tardelli et al., 2020). Our findings show that SST is of interest to many PWUS, particularly those who desire eventual abstinence, although such programs will have limited appeal depending on medication dosages/schedules and operational contexts. Our participants’ concerns surrounding dosing and felt effects were echoed in a recent qualitative study of a clinic-based pilot program administering dextroamphetamine to a participant sample similar to our own (Palis et al., 2021). This pilot administered up to 120 mg/day of dextroamphetamine—twice the maximum approved daily dose for prescription amphetamines—and found a need for still higher dosing options for participants to achieve their desired feeling (Palis et al., 2021). This suggests that trials have yet to adequately study candidate medications in doses high enough to derive therapeutic benefit for PWUS, and points to the need for SST trials that are more pragmatic in their medication dosages/schedules and decenter abstinence as the key metric of treatment success to instead center individual treatment goals.

While there are possible opioid treatment models that could inform implementation of pilot SST interventions (e.g., methadone, injectable hydromorphone), findings suggest that drawing on existing interventions absent participatory planning processes may limit benefits by recreating barriers embedded within these models. Strict program requirements, such as attendance policies and urine drug screening, have been discussed as detrimental to patient engagement in various opioid treatment contexts, even when there are no punitive consequences (Harris & McElrath, 2012; Pilarinos et al., 2022). In our study, participants foresaw that directly transposing the operational contexts of existing opioid treatment models to SST would undermine agency in care decisions and treatment administration, suggesting that to do so would come at the expense of SST engagement, retention, and effectiveness. Following the onset of the COVID-19 pandemic and the suspension of data collection activities for this study, British Columbia implemented interim clinical guidance for the prescription of pharmaceutical alternatives to illicit drugs, including dextroamphetamine and methylphenidate, to reduce exposure to COVID-19 and reduce risks of withdrawal and exposure to the illicit drug supply (British Columbia Centre on Substance Use, 2020). This clinical guidance has since been adopted for continuation beyond the COVID-19 pandemic, effectively incorporating SST into public health practice (BCCSU, 2022). Experiences following the implementation of this guidance have generally been positive, although many of the barriers anticipated by our participants have been observed, including rigid daily attendance policies, concerns around low dosing, and limitations on autonomy (McNeil et al., 2022). Interestingly, research and reporting on these clinical guidelines is almost exclusively focused on opioids, suggesting the needs of PWUS remain under-prioritized even in a context that has implemented SST.

Concerns related to agency were particularly salient for Indigenous participants, whose perspectives of SST must be situated within a context of colonization that renders treatment services untrustworthy and even harmful (Goodman et al., 2017). It is critical that SST attend to equity concerns throughout planning, implementation, and operations to interrupt the expansion of colonial power dynamics within substance use services. Treatment models that center people with lived experience of drug use in their own care, including with dosage decisions, demonstrate better outcomes and can be instructive in guiding participatory planning processes for prospective SST approaches that are responsive to the specific needs of PWUS and have higher likelihood of uptake (Karazivan et al., 2015; Trujols et al., 2017). Relatedly, our findings suggest that participatory principles must also extend to SST evaluation. Participants in this study discussed a range of potential outcome measures that were personally important to them (e.g., engagement in criminalized income generation, economic security, self-determination, etc.). However, such patient-centered outcome measures are largely unaccounted for in SST trials, underscoring the absence of stimulant users’ voices in treatment-related research. Thus, future SST programming and research should be undertaken in partnership with PWUS and must foreground cultural safety in pursuit of health equity.

In early 2023, a province-wide decriminalization pilot came into effect in BC, removing criminal sanctions for individuals in possession of a cumulative maximum 2.5 g of illicit substances (Ali et al., 2023), though the province has since moved to impose new restrictions on public drug use with the potential to undermine positive impacts of decriminalization on marginalized PWUS. This bears consideration when interpreting our findings, given how criminalization factored into participants’ perceptions of SST. Various international models of decriminalization have been found to be successful in reducing drug seizures and arrests related to drug possession (Stevens et al., 2022). However, recent research from Oregon demonstrated that people who use drugs were reluctant to involve first responders during overdose events because, despite statewide decriminalization, they remained vulnerable to criminal sanctions related to non-drug related arrest warrants and drug-induced homicide charges (Shin et al., 2022). This suggests the limitations of decriminalization when other criminal sanctions are not removed in the context of an increasingly unpredictable drug supply and heightened overdose risk. Further, early research on decriminalization in BC suggests that the imposed threshold limit does not adequately address the risks of drug criminalization, in particular for marginalized PWUS, who often buy and use illicit stimulants in higher quantities (Ali et al., 2023). Thus, while decriminalization is a critical harm reduction tool, it does not negate the need for effective pharmacological options for PWUS.

This study has several limitations. Our sample is drawn from Vancouver and participant recruitment occurred primarily in the Downtown Eastside neighborhood, a low-income inner-city neighborhood characterized by a high prevalence of drug use, overdose fatalities, and housing insecurity, and which includes a higher concentration of health and social services targeted towards illicit drug use than likely found in other jurisdictions. More broadly, Vancouver’s approach to drug use is among the more progressive in North America and includes novel opioid agonist treatment and safer supply programs. Therefore, findings may not reflect knowledge and perceptions of prospective SST of PWUS in other contexts. Further, since data were collected the local street-level stimulant supply has grown increasingly volatile due to continued fentanyl- and emerging benzodiazepine-adulteration. Findings may not be reflective of the current degree of overdose vulnerability among PWUS, or of PWUS in other (e.g., less adulterated) drug markets.

In conclusion, this study demonstrates that, if implemented in a way that centers the needs of PWUS, SST may lead to a range of health, social, and economic advantages. However, drawing on existing opioid treatment models may compromise this by recreating the barriers embedded in these models. There is an urgent need for effective pharmacological treatment for SUD, and our findings underscore the importance of pragmatic and participatory planning processes to optimize SST engagement, retention, and effectiveness in real-world contexts.