Prevalence of alcohol and cocaine co-use

Alcohol, either as the primary or secondary substance, is the most frequently reported substance across all SUD treatment admissions at 49% (Center for Behavioral Health Statistics and Quality, 2017). Alcohol and cocaine are the two most frequently co-used substances among individuals seeking SUD treatment (Kedia, Sell, & Relyea, Reference Kedia, Sell and Relyea2007; Liu, Williamson, Setlow, Cottler, & Knackstedt, Reference Liu, Williamson, Setlow, Cottler and Knackstedt2018). Alcohol use disorder (AUD) is typically reported as the primary SUD, while cocaine use disorder (CUD) is commonly reported as a secondary SUD (Center for Behavioral Health Statistics and Quality, 2017). For individuals with primary CUD, secondary AUD is frequently reported, with an estimated 60% of individuals with CUD regardless of treatment status also meeting the criteria for AUD (Heil, Badger, & Higgins, Reference Heil, Badger and Higgins2001). Alcohol and cocaine use are treated simultaneously in nearly all SUD treatment settings.

Prevalence of alcohol and tobacco co-use

Tobacco products and alcohol are, commonly co-used; individuals who meet the criteria for both AUD and TUD represent 34.0% of all AUD cases and 22.8% of all TUD cases (Grant, Hasin, Chou, Stinson, & Dawson, Reference Grant, Hasin, Chou, Stinson and Dawson2004). The prevalence of co-occurrence among individuals seeking SUD treatment is unknown as this information is not routinely collected at intake or discharge. The link between TUD and AUD seems persistent regardless of interest in quitting cigarettes; individuals with SUD experience significantly lower quit rates and more rapid relapse than individuals without SUDs (Weinberger, Gbedemah, & Goodwin, Reference Weinberger, Gbedemah and Goodwin2017a; Weinberger et al., Reference Weinberger, Platt, Esan, Galea, Erlich and Goodwin2017b, Reference Weinberger, Pacek, Wall, Gbedemah, Lee and Goodwin2020). This is potentially due to a variety of barriers to effective cessation interventions in this population (Schroeder & Morris, Reference Schroeder and Morris2010), as well as changes to the brain reward pathway in those who co-use (Bandiera et al., Reference Bandiera, Almeida, Hansen, Pulcinelli, Caletti, de Paula and Gomez2020; Lajtha & Sershen, Reference Lajtha and Sershen2010). Overall, the lack of emphasis on tobacco treatment in the SUD treatment setting does not appear attributable to low prevalence of co-use or lack of evidence-based treatments, as these are more plentiful for TUD than any other SUD (Thurgood, McNeill, Clark-Carter, & Brose, Reference Thurgood, McNeill, Clark-Carter and Brose2016). Lack of assessment and diagnosis of TUD, especially as primary diagnosis, and insufficient third-party payer reimbursement for TUD treatment effectively prohibit comprehensive treatment of SUDs by leaving TUD untreated (Williams, Steinberg, Kenefake, & Burke, Reference Williams, Steinberg, Kenefake and Burke2016).

The harms of alcohol and cocaine

The physical, psychiatric, and social ramifications of AUD and CUD, individually and in combination, are well documented (Hedden, Malcolm, & Latimer, Reference Hedden, Malcolm and Latimer2009). AUD increases the risk of physical injury, hastens the development of chronic health conditions, and provokes and worsens mental health (CDC, 2018; WHO, 2010). CUD is implicated in unpredictable or aberrant behavior, gastrointestinal damage, cardiovascular complications, and impaired cognitive functioning (NIDA, 2016; WHO, 2010). Alcohol and cocaine co-use is also associated with increased risk of cardiovascular disease, mental health problems, and interpersonal difficulties, over and above the risk for each individually (Hedden et al., Reference Hedden, Malcolm and Latimer2009). The significant and well-documented health risks associated with alcohol and cocaine used alone or together make AUD and CUD priorities in SUD screening, assessment, and intervention.

The harms of alcohol and tobacco

As discussed earlier, AUD negatively impacts an individual's health in a myriad of ways, including harming cardiovascular, cognitive, mental, and interpersonal well-being. The physical health risks of tobacco use are well-known and extensive, including but not limited to respiratory infections, high blood pressure, diabetes, pregnancy complications, and lung cancer (WHO, 2010). In addition, cigarette use increases the number of mentally unhealthy days (Plurphanswat, Kaestner, & Rodu, Reference Plurphanswat, Kaestner and Rodu2017), and is associated with higher risk of recurrence of major depressive disorder (Bakhshaie, Zvolensky, & Goodwin, Reference Bakhshaie, Zvolensky and Goodwin2015). Co-use of alcohol and tobacco is associated with greater physical health risks relative to the use of either alone (Schroeder, Reference Schroeder2017), and is associated with mental health problems (Cohn et al., Reference Cohn, Johnson, Rose, Pearson, Villanti and Stanton2018). Among individuals in long-term recovery for AUD, cigarette smoking-related health conditions are the most common cause of death (Alcoholism: Clinical & Experimental Research, 2008). As such, the rationale for excluding tobacco use from the treatment setting does appear to be based on the lack of potential harm.

Alcohol and cocaine co-use treatment

Co-occurring alcohol and cocaine SUDs, compared with either alone, produce additional challenges for successful treatment. These challenges include intertwined cues, modified and enhanced intoxication effects, and increased use of both substances. Individuals who become accustomed to cocaine use after consuming alcohol find themselves ‘craving’ cocaine when confronted with the conditioned cue (i.e. alcohol). When two or more substances have reciprocal cues, they are ‘intertwined’. This poses significant difficulties for those who have a combined cocaine and alcohol polysubstance disorder, as they require complete abstinence from both substances to avoid eliciting a compounding desire for one substance or the other (Marks, Pike, Stoops, & Rush, Reference Marks, Pike, Stoops and Rush2015).

Cocaine and alcohol can also modulate user experiences to amplify positive effects and mitigate negative consequences (Perez-Reyes, Reference Perez-Reyes1994). When consumed together, alcohol and cocaine create cocaethylene, a metabolite with additional psychoactive effects. Individuals who co-use cocaine and alcohol experience increased euphoria compared with the use of either substance alone (Farre et al., Reference Farre, de la Torre, Gonzalez, Teran, Roset, Menoyo and Cami1997; Liu et al., Reference Liu, Williamson, Setlow, Cottler and Knackstedt2018; McCance-Katz, Kosten, & Jatlow, Reference McCance-Katz, Kosten and Jatlow1998). Furthermore, cocaine may be used to strategically counteract alcohol's depressant effects, and alcohol may likewise be used to mitigate cocaine's withdrawal symptoms (Margolin, Avants, & Kosten, Reference Margolin, Avants and Kosten1996). Likely related to many of the reasons above, research indicates that alcohol and cocaine co-use is associated with increased frequency of use of both substances (Gossop, Manning, & Ridge, Reference Gossop, Manning and Ridge2006; Heil et al., Reference Heil, Badger and Higgins2001). Given that alcohol and cocaine cessation is required upon treatment entry, SUD interventions and programs acknowledge how alcohol and cocaine use are often inextricably entangled.

Evidence-based interventions for different SUDs usually follow similar intervention methods, such as pharmacotherapy, behavioral therapy, and addressing comorbidities, with slight substance-specific differences and differences unique to the individual. While alcohol and cocaine use are strongly associated in populations receiving treatment (Pennings, Leccese, & Wolff, Reference Pennings, Leccese and Wolff2002), there are no nationally mandated evidence-based clinical guidelines for treating co-occurring AUD and CUD. The APA recommends incorporating evidence-based practices for each SUD into an individualized plan for the patient (APA, 2006). Similarly, some local AA groups incorporate support for both alcohol and cocaine and recommend that individuals with co-occurring SUDs attend other 12-step groups (e.g. Narcotics Anonymous, Cocaine Anonymous) (W, Reference W2017). Successful CUD treatment outcomes are predicted by lower alcohol consumption after CUD treatment, while research specific to the effect of cocaine use on AUD treatment success is sparse. However, data suggest that co-morbid CUD causes an increased early treatment drop-out effect due to the difficult nature of initial cocaine abstinence, likely leading to significant difficulties in obtaining alcohol abstinence (Kampman et al., Reference Kampman, Pettinati, Volpicelli, Oslin, Lipkin, Sparkman and O'Brien2004).

Alcohol and tobacco co-use treatment

Alcohol and tobacco co-use presents challenges to treatment success not unlike that of alcohol and cocaine co-use: intertwined cues, modified and enhanced intoxication effects, and increased use of both substances. The intertwined cues for individuals with co-occurring AUD and TUD are similar for co-occurring AUD and CUD – those who use both cigarettes and alcohol find themselves wanting to use alcohol while they are smoking cigarettes, or smoke cigarettes while they are consuming alcohol.

Regardless of whether an individual uses alcohol or tobacco first, use of one substance appears to increase craving for the other (Bien & Burge, Reference Bien and Burge1990; Schroeder, Reference Schroeder2017; Sharma, Lodhi, Sahota, & Thakkar, Reference Sharma, Lodhi, Sahota and Thakkar2015). Smoking cigarettes while drinking alcohol may counteract alcohol's depressive effects, increase feelings of intoxication, and allow the individual to continue drinking (Sharma et al., Reference Sharma, Lodhi, Sahota and Thakkar2015; Verplaetse & McKee, Reference Verplaetse and McKee2017). With increased alcohol consumption, one needs to smoke more to feel the effects of tobacco (Kohut, Reference Kohut2017). Due to the reinforcing nature of alcohol and tobacco co-use, individuals using both substances may experience increased frequency of use and amount of consumption of each substance (Gulliver et al., Reference Gulliver, Rohsenow, Colby, Dey, Abrams, Niaura and Monti1995; Rohsenow et al., Reference Rohsenow, Monti, Colby, Gulliver, Sirota, Niaura and Abrams1997; Schroeder, Reference Schroeder2017; Verplaetse & McKee, Reference Verplaetse and McKee2017). The degree to which alcohol and tobacco co-use is comparably entangled with that of alcohol and cocaine co-use illustrates the need for integrated treatment that recognizes the role of each substance in perpetuating addiction and how both may be a barrier to recovery.

Akin to the lack of integrated treatment for co-occurring AUD and CUD, there are no established interventions for combined AUD and TUD treatment, though concurrent v. delayed smoking cessation is associated with lower alcohol craving and expectations of more negative effects of alcohol use (Cooney et al., Reference Cooney, Litt, Sevarino, Levy, Kranitz, Sackler and Cooney2015). Smoking cessation interventions are inconsistently provided in treatment settings and are generally optional, if available. Data on who receives TUD treatment indicate individualized, situational, and biased allocation. SUD patients experiencing physical and psychological distress receive fewer tobacco cessation services, but patients who ask for cessation services and patients who receive treatment at tobacco-free facilities are more likely to receive assistance (Guydish et al., Reference Guydish, Yip, Le, Gubner, Williams and Delucchi2019). In contrast with cocaine use in the context of AUD treatment, abstinence from tobacco is not required or emphasized.

Although the health consequences of tobacco are universally recognized, much debate remains about the role of smoking cessation interventions in SUD treatment. Addiction providers historically believed that smoking cessation during recovery would increase risk of relapse to other substance use and recommended smoking cessation after successful SUD treatment (Guydish et al., Reference Guydish, Passalacqua, Tajima and Manser2007; Patten et al., Reference Patten, Martin and Owen1996). However, available research indicates that smoking cessation interventions do not compromise SUD treatment outcomes, and instead may facilitate better outcomes when offered with SUD treatment (Baca & Yahne, Reference Baca and Yahne2009; Bobo, McIlvain, Lando, Walker, & Leed-Kelly, Reference Bobo, McIlvain, Lando, Walker and Leed-Kelly1998; Epstein, Marrone, Heishman, Schmittner, & Preston, Reference Epstein, Marrone, Heishman, Schmittner and Preston2010). In a meta-analysis of 19 randomized controlled trials, smoking interventions concurrent with SUD treatment were associated with a 25% increased chance of long-term substance abstinence (Prochaska et al., Reference Prochaska, Delucchi and Hall2004). Several studies have suggested that smoking v. no smoking is associated with poorer AUD treatment outcomes, including increased risk of relapse (Joseph, Willenbring, Nugent, & Nelson, Reference Joseph, Willenbring, Nugent and Nelson2004; Satre, Kohn, & Weisner, Reference Satre, Kohn and Weisner2007; Stuyt, Reference Stuyt2015). As such, the omission of tobacco treatment and abstinence from tobacco as a fundamental component of SUD treatment appears to contradict available evidence.

Challenges to tobacco cessation in SUD treatment settings

The physical health consequences of tobacco are devastating, with half a million US adults dying from tobacco-related causes annually (Carter et al., Reference Carter, Abnet, Feskanich, Freedman, Hartge, Lewis and Jacobs2015; CDC, 2014). Nonetheless, cigarette smoking continues to be regarded as irrelevant or of far lesser importance in SUD treatment settings. There are mixed opinions about this differential treatment among SUD treatment providers. These sentiments may be partially explained by the absence of visible tobacco ‘intoxication’ when used in the absence of other substances and the empirically unsupported belief that the effects of smoking are limited to physical consequences; numerous studies indicate that tobacco is associated with poorer mental health outcomes (e.g. Bakhshaie et al., Reference Bakhshaie, Zvolensky and Goodwin2015; Fluharty, Taylor, Grabski, & Munafò, Reference Fluharty, Taylor, Grabski and Munafò2017; Plurphanswat et al., Reference Plurphanswat, Kaestner and Rodu2017).

There are many challenges to incorporating tobacco cessation interventions into recovery-oriented settings. While inpatient facilities are quickly adopting smoke-free policies, it is feared that these policies could drive participants who smoke to leave before completing their treatment (Patten et al., Reference Patten, Martin and Owen1996). Psychoeducation of providers and patients about the benefits of TUD treatment may be necessary due to the erroneous belief that continued smoking enhances mental health and that cessation would undermine mental health recovery or successful treatment of other substance use problems (Gentry, Craig, Holland, & Notley, Reference Gentry, Craig, Holland and Notley2017; Kelly, Greene, Hoffman, Hoeppner, & Bergman, Reference Kelly, Greene, Hoffman, Hoeppner and Bergman2020; Pagano, Tajima, & Guydish, Reference Pagano, Tajima and Guydish2016; Wilson et al., Reference Wilson, Bonevski, Dunlop, Shakeshaft, Tzelepis, Walsberger and Guillaumier2016). Continued smoking alleviates withdrawal symptoms, which can mimic symptoms of anxiety, depression, and psychosis, yet evidence to the contrary suggests that cessation is associated with improved mental health and sustained SUD remission (Bakhshaie et al., Reference Bakhshaie, Zvolensky and Goodwin2015; Bakhshaie, Zvolensky, & Goodwin, Reference Bakhshaie, Zvolensky and Goodwin2016; Patkar et al., Reference Patkar, Lundy, Leone, Weinstein, Gottheil and Steinberg2002). Furthermore, smokers with and without mental disorders report similar levels of motivation to quit smoking (Siru, Hulse, & Tait, Reference Siru, Hulse and Tait2009), and so a focus on making TUD treatment integral within substance use treatment settings, in line with the approach to all other substances, may be more beneficial than assessing whether patients want to or are ready to quit tobacco use. Lack of interest in treatment for TUD would be more effectively addressed with therapeutic rationale, which better aligns with the traditional SUD treatment approach of abstinence from all substances, as well as evidence from the literature on SUD treatment outcomes.

The high prevalence of mental health problems among individuals with SUDs overall may provide additional challenges to successful treatment, but there is no evidence that it presents a disproportionately greater barrier to TUD v. CUD or AUD treatment. Furthermore, diagnosis of mental health problems should not preclude requirement for TUD treatment among substance use care settings. Additional challenges exist toward implementation of tobacco cessation services in SUD treatment facilities desiring them, including inadequate cessation resources, high prevalence of smoking among facility staff, and organizational cultures that do not prioritize cessation (Guydish et al., Reference Guydish, Passalacqua, Tajima and Manser2007; Knudsen, Reference Knudsen2017). Compounding these issues is the proliferation of non-cigarette tobacco products and widespread increase in their use, the increase in polytobacco product use, which is associated with lower odds of quitting (Guydish et al., Reference Guydish, Tajima, Pramod, Le, Gubner, Campbell and Roman2016; Wang-Schweig, Jason, Stevens, & Chaparro, Reference Wang-Schweig, Jason, Stevens and Chaparro2019), and the increase in use of products that are often used to co-administer tobacco and cannabis (Baldassarri et al., Reference Baldassarri, Fiellin, Savage, Madden, Beitel, Dhingra and Barry2019; Dixit, Herbst, & Das, Reference Dixit, Herbst and Das2021; Guydish et al., Reference Guydish, Tajima, Pramod, Le, Gubner, Campbell and Roman2016; Wang-Schweig et al., Reference Wang-Schweig, Jason, Stevens and Chaparro2019). E-cigarettes, for example, are often permitted in SUD treatment facilities where combustible tobacco use is prohibited (Wang-Schweig et al., Reference Wang-Schweig, Jason, Stevens and Chaparro2019).

Public health implications

The current paper presents an empirical perspective on the debate over whether to treat TUD in SUD treatment settings. The weight of the available evidence suggests that continued smoking is associated with poorer SUD treatment outcomes and increased risk of relapse during SUD recovery. Available data on treatment outcomes for cocaine and alcohol co-use mirror those of tobacco and alcohol co-use, suggesting a major discrepancy in the perception v. the reality of the impact of tobacco and alcohol co-use on SUD recovery.

Additionally, no evidence to date suggests that tobacco use is an effective tool in remaining abstinent from other substance use. Yet, it is possible that offering tobacco treatment services as a follow-up to AUD treatment may be more effective for individuals who do not request simultaneous treatment (Kodl, Fu, & Joseph, Reference Kodl, Fu and Joseph2006). This question has not been explored empirically but warrants thorough investigation given the widespread practice and profound risks of tobacco use. Regardless of provider preferences, philosophies, or the historical background of SUD treatment resources, the data suggest that continued smoking may be undermining SUD treatment efforts. As we continue to develop evidence-based SUD treatment guidelines, it seems illogical to continue with the status quo of sustained or encouraged tobacco use. A change this profound requires resources, time, and attention, as well as input from all key stakeholders, to address and change longstanding culture. As we amass more data, re-classification of cigarette use within the SUD treatment model as part of the problem, rather than inconsequential, has the potential to make a profound impact toward moving the field forward.