Collecting Research on Abstinence versus Moderation

After coming across a surprisingly sparse number of research studies on the value of abstinence versus moderation, I have been keeping a running list and would love your input! The list below includes studies even if they don't do a direction comparison between abstinence and moderation, and simply report positive benefit with one approach or the other.

Studies:

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1. [Alcohol] Drinking goal choice and outcomes in a Web-based alcohol intervention: Results from VetChange (2015) - Compared to those with a abstinence-only goal, those with a moderation-only goal were more likely to be drinking outside the NIAAA low-risk drinking guidelines within 3-months (84% vs. 25%, respectively).
2. [Alcohol] Rates and correlates of relapse among individuals in remission from DSM-IV alcohol dependence: a 3-year follow-up (2007) - A study with 3 years of follow-up showed that among patients in remission (including abstinent, low risk, and risky drinkers) from alcohol use disorder (AUD), abstinent individuals were less likely to relapse.
3. [Alcohol] Differences between abstinent and non-abstinent individuals in recovery from alcohol use disorders (2014) - Younger age, no prior treatment or AA involvement, fewer dependence symptoms and less time in recovery all significantly related to non-abstinent recovery. Abstainers reported significantly higher quality of life (QOL) than non-abstainers (B=0.39 for abstinence vs. non-abstinence), and abstinence was one of the strongest correlates of QOL, even beyond sociodemographic variables like education.
4. [Alcohol] Profiles of confidence and commitment to change as predictors of moderated drinking: A person-centered approach (2014) - Individuals confident in their ability to reduce (moderate) heavy drinking are most likely to respond well to a moderation-focused treatment and, as authors point out, they may be more willing to try abstaining on certain days to reach their overall moderation goal.
5. [Substances] Abstinence versus moderation recovery pathways following resolution of a substance use problem: Prevalence, predictors, and relationship to psychosocial well-being in a U.S. national sample (2021) (uses 2017 National Recovery Study Data) - About half of Americans who self-identify as having resolved an AOD problem continue to use AOD in some form. It appears that, although for many abstinence is not necessary to overcome an AOD problem, it is likely to lead to better functioning and greater well-being. Further, people appear to gravitate toward abstinence/lower risk substance use with greater time since problem resolution. Of this nationally representative sample of individuals who report having resolved an AOD problem: 20.3% report continuous abstinence; 33.7% current abstinence; 21.0% current use of a secondary substance; 16.2% current use of a primary substance; and 8.8% use of both a secondary and a primary substances.
6. [Substances] Substance Abuse and Mental Health Services Administration (SAMHSA) 2023 report Recovery from Substance Use and Mental Health Problems Among Adults in the United States (uses 2021 National Survey on Drug Use and Health (NSDUH) - 20.9 million Americans consider themselves to be in recovery or to have recovered from their drug or alcohol use problem. Of this group, in the past year: 65% report alcohol use, 68% marijuana use, 60% cocaine use and 61% hallucinogens.
7. [Cannabis] Abstinence and reduced frequency of use are associated with improvements in quality of life (QoL) among treatment-seekers with cannabis use disorder (2018) - Abstinence and lower frequency of use are associated with higher QoL, regardless of gender. Results:?No significant association between baseline cannabis use and QoL was found. End of study abstinence (p = .006) and reduced proportion of using days (p = .004) were each significantly associated with end of study QoL. Reduction in grams (usage) was not associated with QoL at end of study.
8. [Alcohol] Regional cortical thickness recovery with extended abstinence after treatment in those with alcohol use disorder (2024) - Researchers discovered that the brains of those who abstained from alcohol for approximately 7.3 months exhibited significant improvements in brain structure, suggesting a remarkable potential for recovery. This new finding, provides hope for people with alcohol use disorders and underscores the importance of sustained abstinence.
9. [Alcohol] Reductions in WHO risk drinking levels correlate with alcohol craving among individuals with alcohol use disorder (2023) - Individuals with WHO risk drinking level reductions report significantly lower craving compared to those who did not achieve meaningful reductions in drinking. The results provide evidence that drinking reductions mitigate craving.
10. [Opioid] Patient Characteristics Associated with Opioid Abstinence after Participation in a Trial of Buprenorphine versus Injectable Naltrexone (2022) (X:BOT trial) - Of 428 participants, 33% reported abstinence from non-prescribed opioids at 8-months. Participants were more likely to be opioid abstinent if 1) randomized to extended-release naltrexone compared to buprenorphine-naloxone or those off OUD pharmacotherapy, 2) had successfully inducted onto either study medication, 3) had longer time on study medication, 4) reported a greater number of abstinent weeks, or 5) had longer time to relapse during the 24-week treatment trial. Relapse was defined as opioid use for 4 consecutive weeks or 7 consecutive days in the past month.
11. [Opioid] Naturalistic follow-up after a trial of medications for opioid use disorder: Medication status, opioid use, and relapse (2021) (X:BOT trial) - There was no difference in abstinence rates between those on or off MOUD (sublingual buprenorphine, methadone, injectable naltrexone) (33% versus 34%). Participants on medication had fewer opioid use days, fewer met relapse criteria (defined as opioid use for 4 consecutive weeks or 7 consecutive days in the past month), less stimulant and sedative use. There was no difference in abstinence rates between those on or off MOUD (defined as no (non-prescribed) opioid use in the 30-days prior to the 8-month visit using self-report and a negative or missing urine sample). A greater proportion of participants on extended-release naltrexone (53.4%) were abstinent from non-prescribed opioids compared to those on buprenorphine-naloxone (23.3%).
12. [Opioid] Prior studies that have examined correlates of opioid abstinence among individuals with opioid use disorder (on or off MOUD) finding abstinence is positively associated with longer duration on MOUD (Nosyk et al., 2013; Zhu et al., 2018), female gender (Darke et al., 2015), older age (Dreifuss et al., 2013; Naji et al., 2016), more social support (Dennis et al., 2007; Flynn et al., 2003; Zhu et al., 2018), employment (Dennis et al., 2007; Flynn et al., 2003; McKenna, 2017; Nosyk et al., 2013), less impulsivity (Zhu et al., 2018), older age at first opioid use (Zhu et al., 2018), fewer lifetime treatment episodes (Darke et al., 2015).