Cannabis use during treatment for alcohol use disorders predicts alcohol treatment outcomes

Abstract

Aims (1) Compare post-treatment alcohol use between those who use cannabis and those who abstain during treatment for alcohol use disorders (AUD). (2) Examine potential cannabis use thresholds by comparing post-treatment alcohol use between four frequency groups of cannabis users relative to abstainers. Design Secondary analyses of the COMBINE Study, a randomized control trial of AUD treatments. The current study compares longitudinal drinking data between those who used cannabis vs. those who abstained during COMBINE treatment. Setting The COMBINE Study treatments were delivered on an outpatient basis over 16 weeks. The current analyses include 206 cannabis users and 999 cannabis abstainers. Participants All participants met diagnosis of primary alcohol dependence (N = 1,383). Measurements Primary exposures were any cannabis use and quartiles of cannabis use (Q1: 1–4 use days during treatment, Q2: 5–9 days, Q3: 10–44 days, Q4: 45–112 days). Outcomes were percent days abstinent from alcohol (PDA), drinks per drinking day (DPDD), and percent heavy drinking days (PHD), all measured at treatment end and one year post-treatment. Findings Compared with no cannabis use, any cannabis use during treatment was associated with 4.35% (95% CI: −8.68, −0.02), or approximately four fewer alcohol abstinent days at the end of treatment. This association weakened by one-year post-treatment (95% CI: −9.78, 0.54). Compared with no cannabis use, only those in the second quartile of cannabis use (those who used once or twice per month during treatment) had 8.81% (95% CI: −17.00, −0.63), or approximately ten fewer days alcohol abstinent at end of treatment, and 11.82% (95% CI: −21.56, −2.07), or approximately 13 fewer alcohol abstinent days one-year post-treatment. Neither any cannabis use nor quartiles were associated with DPDD or PHD at either time-point. Conclusions Among individuals in alcohol treatment, any cannabis use (compared with none) is related to significantly lower percent days abstinent from alcohol post-treatment, though only among those who used cannabis once or twice per month.

Cannabis use during alcohol treatment is associated with alcohol-related problems one-year post-treatment

“…The lack of significant associations between cannabis use and alcohol-related problems across most domains is interesting and consistent with previous findings of a lack of association between heavy drinking and cannabis frequency in the COMBINE sample (Subbaraman et al, 2017). Taken together, the results from the current and previous studies signal that more work is needed to understand whether there are safe levels of cannabis use for individuals in AUD treatment.…”

“…The primary exposure was cannabis use during treatment, defined by quartiles among users (n = 206) with cannabis abstainers as the referent (n = 999). Following previously published analyses that showed differential effects of cannabis according to frequency of use (Subbaraman et al, 2017), cannabis users were grouped into quartiles based on the distribution of the percentage of days of cannabis use during the 16week treatment period: Quartile 1 (Q1; approximately 1–4% of days, or less than 1x/month), Quartile 2 (Q2; approximately 5–8% of days, or 1–2x/month), Quartile 3 (Q3; approximately 9 – 39% of days, or 4–8x/month), and Quartile 4 (Q4; approximately 40–100% of days, or 12x/month or more).…”

“…As compared to no cannabis use, any cannabis use during treatment was related to a significantly lower percentage of days abstinent from alcohol as far as one year post-treatment, although only among the second quartile of cannabis users, i.e., those who used cannabis once or twice per month (Subbaraman et al, 2017). This suggests that the relationship between cannabis and alcohol use is probably not linear, and might be driven by individuals who substitute cannabis for alcohol by using cannabis more frequently and alcohol less frequently (Subbaraman et al, 2017). Cannabis use was not related to drinks per drinking day or heavy drinking days, which raises questions regarding both whether these individuals are still at increased risk for alcohol-related problems, as well as how these individuals are using cannabis and alcohol together vs. separately.…”

Marijuana use is associated with intimate partner violence perpetration among men arrested for domestic violence.

“…Given the high prevalence of marijuana use among men in BIPs identified in the present study, and our preliminary finding that marijuana and alcohol use and problems interact to predict sexual IPV, it is plausible that marijuana use could negatively impact BIP outcomes. Indeed, individuals who are in alcohol treatment have poorer outcomes when they are using marijuana during treatment relative to individuals who do not use marijuana during treatment (Subbaraman, Metrik, Patterson, & Swift, 2017). Therefore, BIPs should consider targeting marijuana use in their programs in order to determine whether marijuana use treatment impacts BIP outcomes.…”

Marijuana use in the context of alcohol interventions for mandated college students

“…In contrast, literature examining the impact of marijuana use on the treatment of other substances is mixed. With the exception of a few studies that do not show marijuana use to negatively influence alcohol or smoking cessation outcomes (Magill et al, 2009; Metrik et al, 2011), many studies have demonstrated that using marijuana before or during alcohol treatment is associated with higher levels of drinking at follow-up (Alessi et al, 2011; Mojarrad et al, 2014; Subbaraman et al, 2016). For example, among alcohol dependent individuals, those who used marijuana during alcohol treatment reported fewer days abstinent from alcohol one year following treatment than those who did not use marijuana (Subbaraman et al, 2016).…”