Table 2 Characteristics of Studies Included in Systematic Review

 Abed et al., 2019 [30]

MBRP + Methadone Maintenance Therapy (MMT): 8, 120-min sessions.

No intervention control + MMT.

60 adult Iranian males (MRBP - 30 participants (26 completed), Control −30 participants (29 completed)) undergoing MMT in Isfahan, Iran. Participants were between the ages of 27 and 50 who had undergone MMT within the six months to one year prior to the beginning of the study. Prior heroin use ranged from two to seven years.

Baseline and post-intervention testing of the Heroin Craving Questionnaire (HCQ), and a urinalysis the first, second, and third months after the eight-week intervention.

Primary outcomes were differences among the scores of craving and desire (HCQ) and lapse occurrence (drug urine tests).

The mean of the post-test scores in the subscales of desire to use on the HCQ (pre-test M = 34.27; post-test M = 18.93), intention to use (pre-test M = 30.66; post-test M = 18.42) and anticipation of relief from withdrawal or dysphoria (pre-test M = 38.58; post-test M = 21.66) decreased from pre-test to post-test in the MBRP group. The results revealed a significant difference among the scores in the subscales of craving and the difference in the three subscales of desire to use, intention to use, and anticipation of relief from withdrawal or dysphoria was statistically significant. There was a marked reduction in positive drug tests for the MBRP group (9, 7, 14%) compared with the control (23, 24, 22%) over the three-month follow-up window.

There is a potential lack of generalizability in the study. The population was comprised of only male MMT patients. Without an active control group, it is hard to determine the effects of MBRP vs. the MMT.

 Brown et al., 2020 [31]

Rolling MBRP + tDCS: 8, 120-min sessions with the first 30-min consisting of tDCS.

Rolling MBRP + sham tDCS: 8, 120-min sessions with the first 30-min consisting of the sham tDCS.

68 adults interested in reducing their drinking (Active tDCS = 36; sham tDCS = 32). 52.9% male, 52.16 (13.6) years old, 50.0% non-Hispanic white. 98.5% met DSM-5 criteria for current AUD with the remaining participant meeting criteria for lifetime AUD.

Baseline and post-intervention.

Alcohol cue-related hypersensitivity: EEG was recorded to capture an event-related component shown to relate to emotionally salient stimuli. The late positive potential (LPP), and self-reported craving and negative affect were recorded during an image presentation task.

There was a main effect of time in predicting craving ratings and LPP amplitudes for the alcohol images, such that craving ratings and LPP amplitudes significantly decreased over time. Also, there was an effect of group attendance, such that more groups attended was associated with lower craving rations. There was no effect of active versus sham tDCS in predicting craving ratings. Significantly higher LPP amplitudes were associated with the active tDCS compared with the sham tDCS.

The retention for the EEG assessment from the baseline to the post- treatment follow-up was low (54.4% completed both assessments).

 Carroll et al., 2018 [32]

MBRP: 8, 120-min sessions.

Relapse prevention (RP): 8, 120-min sessions. Topics included self-efficacy, coping skills, goal setting, problem solving, and social support.

TAU: process-oriented groups, such as 12-step, as facilitated regularly at the community treatment agency.

34 patients (MBRP = 12; RP = 12; TAU = 10) from a private, non-profit substance abuse care facility in the Pacific Northwest. 43.4 (9.7) years old, 73% male, and 47% non-Hispanic White.

Post-intervention (within the 2 months following completion of the larger RCT intervention).

The primary outcome was tonic and phasic heart rate variability (HRV) to a cognitive stressor (Electrocardiography (ECG)). Secondary outcomes included self- reported anxiety and craving during the cognitive stressor.

Prior to performing the stressor task, MBRP evinced greater tonic HF-HRV than RP, HF-HRV did not significantly differ between RP and TAU. All of the pairwise comparisons were significant (TAU vs RP, p = 0.013; TAU vs MBRP, p < 0.001; RP vs MBRP, p = 0.011) for phasic HRV. State anxiety increased during the stressor and quickly subsided during recovery in all three treatment groups. Groups did not differ significantly in baseline or recovery values, nor did they differ in rates of return to baseline. Group differences in baseline, recovery, or rates of recovery for craving were not observed.

This laboratory assessment was conducted as an extension of a large- scale clinical trial, and in consideration of participant burden, there is only one assessment time point with a relatively small sample.

 Davis et at., 2018 [33]

Rolling MBRP + treatment normally provided by the residential facility: 8, 90- min classes that were held twice weekly. Members were enrolled as they entered the residential facility (as opposed to the standard 8- week cohort-based protocol). The basic treatment practice employed at the residential treatment center was a mix of cognitive-behavioral treatment and 12-step approach to recovery.

TAU + treatment normally provided by the residential facility: 8, 90-min sessions held twice weekly that were social support groups (Alcoholics and Narcotics Anonymous).

79 young adults (MBRP = 44; TAU = 35) enrolled in a residential SUD treatment facility. 25.3 (2.7) years old, the majority of clients were non-Hispanic White (91%), male (65%), and had less than a high school education (mean years of education was 11.9). Over 90% of participants were polysubstance users, and average length of stay at the treatment facility was 41 (26.2) days

Baseline, bi-weekly (every 2 weeks) assessments during treatment, 1- and 6- month post-treatment assessments.

Primary outcomes were perceived stress (PSS), craving (GAIN assessment), and substance use (SFS).

Those assigned to the TAU group tended to show immediate increases in substance use that peaked and subsequently plateaued around 13 weeks after treatment. The MBRP group’s substance-use trajectories differed markedly. Participants reported statistically significant declines in their level of craving during the treatment phase. These declines were statistically identical across treatment conditions. Those assigned to the MBRP condition largely maintained their low levels of craving throughout the remainder of the 28- week study period, those assigned to the TAU condition showed rather immediate and substantial increases in their craving levels, before plateauing approximately 14 weeks post-treatment. Participants in MBPR showed statistically significant improvements in their stress levels during the 8-week intervention.

Small sample size, but this is the first study to provide evidence and support for the use of MBRP among high risk, marginalized young adults in residential substance use disorder treatment.

 Davis et at., 2019 [34]

Rolling MBRP + treatment normally provided by the residential facility: 8, 90- min classes that were held twice weekly. Members were enrolled as they entered the residential facility (as opposed to the standard 8- week cohort-based protocol). The treatment normally provided was a combination of cognitive-behavioral treatment and the 12-step approach to recovery.

TAU + treatment normally provided by the residential facility: 8, 90-min sessions held twice weekly that were social support groups (Alcoholics and Narcotics Anonymous).

79 young adults (MBRP = 44; TAU = 35) enrolled in a residential SUD treatment facility. 25.3 (2.7) years old, the majority of clients were non-Hispanic White (91%), male (65%), and had less than a high school education (mean years of education was 11.9). Over 90% of participants were polysubstance users, and average length of stay at the treatment facility was 41 (26.2) days.

Baseline, bi-weekly (every 2 weeks) assessments during treatment, 1- and 6- month post-treatment assessments.

Primary outcomes were impulsivity (UPPS-P impulsive behavior scale) and substance use (SFS).

Participants receiving MBRP evidenced significant reductions in all facets of impulsivity except for sensation seeking during treatment, and these reductions were significantly greater than TAU for all facets except positive urgency. These treatment gains were maintained through the 6-month follow-up.

The MBRP intervention in the current study made use of a rolling group admission, allowing new patients at the residential facility to enter the group and departing patients to leave it. This may be a limitation because patients could receive instruction out of order, weakening the integrity of the treatment.

 Glasner-Edwards et al., 2017 [35]

MBRP + contingency management (CM): 8, 75- min sessions. Modified sessions from 120 min to increase engagement by shortening meditation practices. All participants in the trial also received CM, which consisted of twice-weekly visits of the fishbowl method, with rewards based on urine drug screes.

Health education (HE) + contingency management (CM): 8, 75-min sessions. Addressed 6 different types of health (e.g., intellectual, social, emotional, physical, environmental, spiritual). All participants in this condition also received twice-weekly CM visits.

63 adults (MBRP + CM = 31; HE + CM = 32) with DSM-IV stimulant dependence recruited from the community. 71.4% male, 45.3 (8.9) years old, 30.2% non-Hispanic white, 43% with a co-occurring Axis 1 disorder.

Baseline and 1- month post-treatment follow- up.

Substance use outcomes were stimulant-positive urine drug screens and the ASI addiction severity score. Psychiatric severity outcomes were the BDI, BAI, and ASI psychiatric severity score.

Hypothesized mediators were emotion regulation (DERS), thought suppression (WBSI), and mindfulness skills (FFMQ).

There was no effect of treatment condition on odds of producing a stimulant-positive urine drug screen over the 8-week intervention phase (73% in MBRP + CM vs. 70% in HE + CM) or change in ASI addiction severity index scores from baseline to the 1-month follow-up.

However, those with co-occurring psychiatric disorders had lower odds of producing a stimulant-positive urine drug screen if they received MBRP + CM vs. HE + CM. MBRP + CM was associated with greater decreases in BDI scores and increases in ASI psychiatric severity scores, but not BAI scores, as compared to HE + CM. There was no significant group x time interaction for any of the putative mechanisms of change (DERS, WBSI, FFMQ) over the study period.

Short follow-up. High attrition rates (23 of the 63 participants terminated study involvement).

Shortened MBRP protocol.

 Hsiao et al., 2019 [36]

MBRP: 8, 120-min sessions

TAU: 90-min sessions 1- 2x/week during the intervention phase. Twelve-step, process-oriented format.

Adults (study 1 n = 168, study 2 n = 198) recruited from an outpatient SUD treatment program who had completed inpatient or intensive outpatient treatment in the previous two weeks. Study 1: 63.7% male, 40.5 (10.3) years old, 53.6% non-Hispanic white. Study 2: 75.1% male, 38.2 (10.9) years old, 52.8% non-Hispanic white.

Study 1: Baseline, post-treatment, 2- and 4-month follow-up Study 2: Baseline, post-treatment, 2-, 4-, 6-, and 12- month follow-up.

Substance use outcome was craving (PACS). Examined a latent mindfulness factor as a mediator (AAQ and acting with awareness and nonjudgment subscales of the FFMQ).

Study 1: The effects of MBRP, as compared to TAU, on AAQ, FFMQ, and PACS scores at post-treatment were small-to-medium (Cohen’s d range from 0.08 to 0.48). The latent mindfulness factor significantly mediated the effects of MBRP, as compared to TAU, on lower craving scores post-treatment.

Study 2: The effects of treatment condition on AAQ, FFMQ, and PACS scores at post-treatment were very small (Cohen’s d range from 0.03 to 0.21) and indicated that those who received TAU reported higher mindfulness scores than those who received MBRP. Higher post-treatment mindfulness was associated with lower post-treatment craving, but those in the MBRP condition did not have greater post-treatment mindfulness scores, and therefore there was not significant mediation.

Low reliability of the AAQ. Study 2 was conducted several years after study 1 from the same treatment program, and therefore the treatment program might have integrated components of MBIs in TAU, mitigating the effect of MBRP. The latent mindfulness factor was not invariant across the two samples, indicating that the measurement of mindfulness was not equivalent across studies.

 Greenfield et al., 2018 [37]

MBRP: 8, 120-min sessions

Relapse prevention (RP): 8, 120-min sessions. Topics included self-efficacy, coping skills, goal setting, problem solving, and social support.

191 adults with SUD who were recruited following inpatient or intensive outpatient treatment. 71.0% male, 39.04 (10.93) years old, 52.9% non-Hispanic white. 43.5% of participants were in groups comprised of > 50% non-Hispanic white participants and 56.5% were in the groups comprised of > 50% racial/ethnic minority participants.

Baseline and 12- month post-treatment follow- up.

Number of drug use days and number of heavy drinking days in the 90-day period before the 12- month post-treatment follow-up.

Among racial/ethnic minority participants, there was not a significant difference in heavy drinking days between MBRP and RP, but those who received MBRP reported fewer drug use days than those who received RP. Among non-Hispanic white participants, those who received MBRP reported fewer heavy drinking days, as compared to those who received RP, but there was no difference in drug use days by treatment condition. Among individuals in groups comprised of > 50% racial/ethnic minority participants, there was not a significant difference in heavy drinking days between MBRP and RP. Among those in groups with > 50% non-Hispanic white participants, those who received MBRP had fewer heavy drinking days than those who received RP. There was not a significant interaction between group racial/ethnic composition and treatment condition in predicting drug use days. In subgroup analyses of only racial/ethnic minority individuals, there was a significant interaction between group race/ethnicity composition and treatment condition in predicting heavy drinking days, but not drug use days. Among racial/ethnic minority individuals in groups comprised of > 50% racial/ethnic minorities, MBRP produced fewer heavy drinking days than RP. There was no difference in heavy drinking days by treatment condition for racial/ethnic minority individuals who were in groups with > 50% whites. In subgroup analyses of only non-Hispanic white

Not able to examine particular racial/ethnic minority groups or differences by acculturation/racial identity.

 Roos et al., 2017 [38]

MBRP: 8, 120-min sessions.

TAU: 12-step facilitation and process-oriented groups. Met 1-2x/wk. for 1.5 h.

RP: (study 1 only) 8, 120-min group sessions. Treatment match control for MBRP

454 adults (study 1 n = 286, study 2 n = 168) recruited from an outpatient SUD treatment program who had completed inpatient or intensive outpatient treatment in the previous two weeks. Study 1: 71.8% male, 38.4 (10.9) years old, 51.6% non-Hispanic white. Study 2: 63.7% male, 40.5 (10.3) years old, 53.6% non-Hispanic white.

Study 1: Baseline, post-treatment, 3-, 6-, 12-month follow-up Study 2: Baseline, post-treatment, 2- and 4-month follow-up.

Alcohol and drug use days were assessed using the TLFB. Substance use disorder symptom severity was measured using the Severity and Dependence Scale (SDS) and the Short Inventory of Problems (SIP). Depression and anxiety symptoms were measured using the BDI-II and BAI, respectively

Study 1: Individuals with high SUD severity and high depression/anxiety and in the MBRP condition experienced significantly fewer heavy drinking days (HDD) and drug use days (DUD) at 12-month follow-up relative to RP and TAU. No effects were seen in low SUD severity and low depression/anxiety class. High SUD severity and low depression/anxiety and MBRP condition predicted significantly fewer 12-month HDD relative to RP or TAU. Study 2: MBRP condition for high severity and high depression/anxiety and high severity SUD and low depression/anxiety had significantly fewer alcohol and other drug use days relative to TAU.

A retrospective self- report measure of days abstinent was used, which may not accurately reflect actual alcohol and drug use days.

 Roos et al., 2019 [39]

MBRP: 8, 120-min sessions

Relapse prevention (RP): 8, 120-min sessions. Topics included self-efficacy, coping skills, goal setting, problem solving, and social support.

117 adults recruited from an outpatient SUD treatment program who had completed inpatient or intensive outpatient treatment in the previous two weeks. 70.9% male, 53.8% non-Hispanic white, 39.0(10.9) years old.

12-month follow- up

Substance use was measured using the TLFB. Severity of substance use disorder was measured using the Severity and Dependence Scale.

Condition predicted fewer drug use days (DUD) such that MBRP participants reported 84% fewer DUD than RP participants. Individual gender and gender group composition not a significant predictor of heavy drinking days (HDD). There was a significant interaction between treatment condition and gender composition on DUD at 12- month follow-up such that MBRP participants had fewer 12-month DUD than those receiving RP and was most pronounced among groups comprised of one-third or more women.

Only a single follow-up 12-months after the completion of the intervention.

 Shorey et al., 2016 [40]

MBRP + Acceptance and Commitment Therapy (ACT): 8 bi-weekly, 90 min sessions. 20–30 min of guided meditation followed by experiential activities and discussion.

Daily homework recordings with a CD player. Attended when normally would have attended process groups.

TAU: Program guided by a 12- step model. Varied daily therapeutic activities including: process groups, AA/NA meetings, coping skills groups, family therapy, exercise groups, acupuncture, individual session with therapists

117 adults (MBI = 64; TAU = 53) in residential substance use disorder treatment (28–30 day program). 74.3% male, 92.2% non-Hispanic White, 41.3 (10.7) years old.

Baseline and post-treatment (at discharge)

Primary outcomes were: craving (PACS), mindfulness (FFMQ), and psychological flexibility (AAQ-SA).

No significant difference between conditions at discharge. Effect sizes between groups were small. MBRP + ACT participants reported lower craving and higher psychological flexibility.

Participants only attended an average of 5.4 of the 8 classes in the MBRP + ACT group. Attendance was not tracked in the TAU condition.

 Weiss de Souza et al., 2020 [41]

MBRP + The Brazilian Ministry of Health’s tobacco cessation standard treatment (ST) protocol: 8, 120- min sessions. The ST protocol was a cognitive- behavioral treatment delivered in four structured weekly sessions and six maintenance follow-up sessions. Sessions were designed to provide information on risks of smoking and benefits of quitting, stimulate self- control and self-management to disrupt the cycle of dependence, and support smokers to become agents of change concerning their behavior. All participants received 4, 90- min structured weekly sessions during the smoking cessation phase of ST, and 6, 90-min ST maintenance sessions (at Weeks 6, 8, 10, 12, 24, and 48)

ST: 4, 90-min structured weekly sessions during the smoking cessation phase, and 6, 90-min maintenance sessions (at Weeks 6, 8, 10, 12, 24, and 48)

86 individuals (ST n = 42; MBRP n = 44) recruited by phone from a waiting list of an outpatient public health tobacco treatment service in a single city in Brazil. 50.34 (10.25) years old, 80.23% female, and 60.46% smoked over 10 cigarettes per day.

Baseline, 4-, 12-, and 24-week follow-ups.

The primary outcome was smoking abstinence (expired carbon monoxide, participants with a carbon monoxide of < 10 were considered abstinent).

Secondary outcomes included levels of mindfulness (FFMQ-BR), craving (QSU), positive and negative affect (PANAS), and depression and anxiety (HAD Scale).

According to the CC analyses, abstinence rates tended to increase between Wk 4 and 12 in both groups (Wk 4: ST [n = 24, 88.9%], MBRP [n = 16, 66.7%]; Wk 12: ST [n = 17, 89.5%], MBRP [n = 12, 85.7%]; Wk 24: ST [n = 6, 66.7%], MBRP [n = 9, 81.8%]). The results of the analysis of secondary outcomes indicated reductions in craving (QSU Factor 2) in the MBRP group from Wk 4 to 12 (M = 17.583) and increases in levels of mindfulness (FFMQ-BR) (M = − 7.833). No other effects were observed for secondary outcomes.

Small sample size with large attrition rates through the 24-week follow-up in both groups (MPRB - 75%; ST - 78.57%).

 Witkiewitz et al., 2019 [42]

MBRP + Active tDCS: 8, 120-min sessions with the first 30-min consisting of tDCS.

MBRP + sham tDCS: Standard MBRP + 8, 120-min sessions with the first 30-min consisting of tDCS.

134 adults interested in reducing their drinking. 59.5% male, 47.6% non- Hispanic white, 38.1% Hispanic, 52.3 (13.0) years old.

Baseline, post-treatment, and two-month follow-up

Primary outcomes were alcohol consumption (TLFB), craving (PACS), alcohol cue-reactivity (assessed using a visual cue task), and inhibitory control (assessed using a stop signal task).

No difference in attendance by condition.

Significant reductions in drinks per drinking day over time. Significant dose effect for the number of groups attended. Significant effects of time and dose for the number of groups attended on percent heavy drinking days and cue reactivity. No effects of active versus sham tDCS on outcomes.

Low follow-up rate.

Exclusion of

individuals with history

of severe alcohol

withdrawal likely

reduced variability in

sample and likely

reduced sample AUD

severity. No biomarkers

of drinking--just self-

report.

 Yaghubi et al., 2017 [43]

MBRP: 8, 120-min sessions.

TAU: Standard for opioid dependence (no substantive description of treatment provided)

70 Iranian adults receiving methadone for opioid dependence. 100% male, 20–45 years old.

Baseline, post-intervention, and 2-month follow-up.

Primary outcomes were impulsive behavior (BIS-11) and opioid (assessed using a biochemical morphine test).

MBRP predicted a significantly higher likelihood of abstinence relative to TAU at post-treatment and follow-up. MBRP also predicted a significant decrease in impulsivity among all subscales and total scores at post-treatment and follow-up.

The study may have limited generalizability because the sample was entirely male.

 Zemestani et al., 2016 [44]

MBRP: 8, 120-min sessions.

TAU: 12-step, process oriented inpatient treatment.

Topics included psycho-education, effects of substance use on interpersonal relationships, rational thinking skills, relapse prevention skills and related themes.

74 Iranian adults receiving inpatient treatment for substance use disorder. 79.7% male, 30.1 (9.4) years old.

Baseline, post- intervention, and 2-month follow-up.

Primary outcomes were depression and anxiety symptoms (BDI-II and the BAI) and craving (PACS).

Participants in the MBRP condition reported significantly lower post-intervention rates of depression, anxiety, and craving as compared to those in TAU. These results were consistent at follow-up.

Many patients did not meet criteria for a major depressive disorder

 Zgierska et al., 2019 [45]

MBRP (tailored to AUD) + standard care: 8, 120-min sessions plus 6+ days per week formal (e.g., body scan for 30 min) and informal (mindfulness of activities) practice.

TAU: Individual and/or group outpatient therapy for alcohol use disorder.

Primary modalities: 12-step facilitation, motivational enhancement therapy, relapse prevention, cognitive behavioral therapy. Encouraged to participate in mutual self-help meetings

112 adults receiving inpatient treatment for alcohol dependence. 56.2% male, 91% non-Hispanic White, 41 (12.2) years old

Baseline, post-treatment, and 18-week follow-up

Primary outcomes were: alcohol consumption (TLFB), alcohol-related consequences (DrInC), stress (PSS), and mindfulness (MAAS).

No significant differences between conditions at post-treatment and follow-up.

Small sample size and there was no blinding. Only one therapist provided all of the treatment.

 Garland et al. 2016 and Garland et al. 2018 (erratum) [15, 46]

MORE: 10, 120-min sessions.

TAU: Groups at the therapeutic community (approximately 2 h/day). Consisted of psychoeducation, coping skills, etc.

CBT: 10, 120-min group sessions. Addressed co-occurring SUD and PTSD via skills training (i.e., not exposure-based).

180 men with co-occurring psychiatric and SUD (MORE = 64, CBT = 64, TAU = 52) who were previously homeless, currently resided in a therapeutic community, and had histories of trauma. MORE: 37.7 (SD = 10.4) years old, 40% non-Hispanic white. CBT: 36.5 (SD = 11.2) years old, 44% non-Hispanic White, TAU: 38.7 (SD = 9.8) years old, 42% non-Hispanic white.

Baseline and post-treatment.

Primary outcomes were craving (PACS), PTSD symptoms (PCL), psychiatric distress (BSI). Secondary outcomes were mindfulness (FFMQ) and positive and negative affect (PANAS).

Craving decreased in all treatments, with greater decreases in MORE, as compared to CBT, but not as compared to TAU. MORE also produced greater decreases in PTSD symptoms than CBT and TAU. Anxiety and depression symptoms decreased across all groups, but there was not a significant treatment x time interaction effect for these outcomes. MORE produced greater increases in mindfulness, as compared to control conditions. MORE produced greater increases in positive affect, as compared to TAU, and decreases in negative affect, as compared to CBT. Changes in mindfulness were significantly negatively correlated with changes in craving and PTSD symptoms and changes in mindfulness mediated the effect of MORE (vs. control conditions) on decreases in craving and PTSD symptoms.

No post-treatment follow-up assessments. Limited generalizability (i.e., to women, individuals not residing in a therapeutic community, etc.)

 Garland et al., 2017 [47]

MORE 8, 120-min sessions.

Support group (SG); 8, 120- min sessions. The topics were pertinent to chronic pain and long-term opioid use and included: the physical and emotional aspects of pain experience, ways of coping with chronic pain, ways of coping with negative emotions, the effect of life stress on pain, the stigma of opioid use, risks of long-term opioid use and opioid dependence, acceptance versus denial, and plans for the future.

115 prescription opioid users (MORE = 57 randomized; SG = 58) for pain relief on a daily or near-daily basis for at least 90 days, and self- reported chronic pain conditions including low-back pain, fibromyalgia, arthritis, cervical pain, or other pain conditions unrelated to cancer. 67.8% female, 48.4 (SD = 13.6) years, 65% non- Hispanic white.

Baseline, post- treatment, 3-month post-treatment follow-up

The primary outcome was opioid attentional bias (AB) as measured by the dot-probe task.

The pretreatment 200 ms opioid AB status significantly moderated the effect of the treatment condition on post-treatment opioid AB, indicating that the effects of treatment significantly differed by pretreatment opioid AB status. There were no significant effects of the treatment condition on post-treatment 2000 ms opioid AB found, nor did pretreatment opioid AB serve as a moderator of treatment effects. The 2000 ms opioid AB did not change from pretreatment to post-treatment, but the reductions in 200 ms opioid AB over the course of treatment predicted lower levels of opioid misuse at 3- month follow-up, suggesting that decreasing attentional fixation on opioid cues may reduce risk of future opioid misuse.

Participants were chronic pain patients that did not have to meet the criteria for OUD. Exploratory secondary analysis with relatively high attrition rates (n = 72; 63% of the randomly allocated sample, 81% of those who attended one or more sessions) completed the treatment.

 Garland et al., 2017 [48]

MORE: 8, 120-min sessions.

Support group (SG): 8, 120- min sessions. The topics were pertinent to chronic pain and long-term opioid use and included: the physical and emotional aspects of pain experience, ways of coping with chronic pain, ways of coping with negative emotions, the effect of life stress on pain, the stigma of opioid use, risks of long-term opioid use and opioid dependence, acceptance versus denial, and plans for the future.

55 chronic pain patients. This subset was taken from a larger sample (115) during an RCT testing the effectiveness of the MORE intervention for individuals with chronic pain. MORE n = 26, SG n = 29, 21 men and 34 women, 48.9 (11.6) years old.

Participants completed EMA via a daily diary in which they rated their current pain level and affect rating each time they took their opioid dose with ratings accepted up to four times each day. Baseline and post-treatment assessment of opioid misuse.

The primary outcomes were pain intensity and affective state (collected via EMA) and aberrant medication-related behavior (COMM).

Aggregated over time, patients in the MORE group showed a 7% reduction in pain, compared to a 3% increase in pain among the SG; thus pain intensity improved over the 8 weeks of MORE relative to the SG (an estimated improvement of 0.7 points on a scale of 0–10). Over the 8 weeks of the study interventions, participants in MORE were 2.75 times more likely to be affectively regulated than participants in the SG. Mean scores on the COMM decreased during treatment by 7.06 in the MORE group and by 3.25 in SG.

The population was not exclusively comprised of opioid misusers (67.3% had COMM scores greater than or equal to 13). Specific response rate to the EMA was not reported. The inclusionary criteria required completion of at least one EMA measurement.

 Garland et al., 2017 [49]

MORE: 8, 120-min sessions.

Support group (SG): 8, 120- min sessions. The topics were pertinent to chronic pain and long-term opioid use and included: the physical and emotional aspects of pain experience, ways of coping with chronic pain, ways of coping with negative emotions, the effect of life stress on pain, the stigma of opioid use, risks of long-term opioid use and opioid dependence, acceptance versus denial, and plans for the future.

51 chronic pain patients (MORE n = 20, SG n = 31).

This subset was taken from a larger sample (115) during an RCT testing the effectiveness of the MORE intervention for individuals with chronic pain. 17 men and 34 women, mean age = 45.7 (13.7) years old.

Baseline and post-treatment.

The primary outcome was changes in relative responsiveness to natural reward and opioid cues from pre- to post-intervention. HR was used to measure cue responsiveness and high- frequency heart rate variability (HRV) to index parasympathetic regulation of hedonic responses, including attention to emotional information.

Positive scores indicated increased natural reward cue-elicited HR relative to opioid cue-elicited HR. Negative scores indicated decreased cue-elicited HR to natural reward cues compared with opioid cue-elicited HR.

There was a significant group × time effect on HRV responsivity, indicating that compared to the SG, the MORE group experienced significantly greater increases in HRV responsivity during affective picture viewing. This would indicate that MORE may be effective at enhancing autonomic regulation of stress created by drug-related stimuli. MORE participants experienced greater reductions in cue-elicited HR. This effect was most prominent for drug cue-elicited HR. This finding may point to the downregulation of response to drug-related cues.

Small sample size. There were only 51 individuals (of the larger 115) who had complete sets of data for this exploratory hypothesis. Participants were chronic pain patients that did not necessarily meet the criteria for OUD.

 Garland et al., 2019 [50]

MORE: 8, 120-min sessions held once a week.

Support Group (SG): 8, 120- min sessions held once a week. Included discussions on topics pertinent to chronic pain and long-term opioid use including: the lived experience of chronic pain, ways of coping with chronic pain; ways of coping with negative emotions, how stressful life events impact pain, the stigma of opioid use and dependence, adverse effects of opioids, acceptance versus denial, and plans for the future.

95 participants recruited from primary care and pain clinics in Salt Lake City, Utah. 56.8 (11.7) years old, 66% female, 89% non-Hispanic White, 122.87 (93.6) months of opioid use.

Baseline, post-intervention, and 3- month follow-up.

Primary outcomes were: positive affect (PANAS), meaning in life (MLQ), savoring (MSS), self- transcendence (NADA), pain severity (BPI), and opioid misuse risk (COMM).

There was a significant effect of intervention group on change in positive affect, meaning in life, savoring, and self-transcendence, indicating that MORE increased these attributes to a greater extent than did the SG. For the clinical variables, there was a significant effect of intervention group on residualized change in pain at post-treatment and change in opioid misuse risk by 3-month follow-up, such that MORE resulted in greater improvements in these variables than did the SG.

The participants were opioid-treated chronic pain patients and did not necessarily meet the criteria for OUD. Attrition rates were high (47.4%), but comparable to that of other opioid interventions.

 Garland et al., 2019 [51]

MORE + MMT: 8, 120-min sessions.

TAU + MMT: 8, 120-min sessions. TAU consisted of individual and group therapy provided by participating in MMT treatment agencies. TAU therapeutic approaches included process-oriented, present-centered therapy, and cognitive-behavioral coping skills training but did not include formal mindfulness-based intervention.

30 individuals enrolled in an MMT program (MORE = 15; TAU = 15). 50.4 (8.44) years old, 50% female, 36.6% non- Hispanic White, 67% reported using heroin in the past 30 days, and had received a median of 7 months of MMT (range < 1 month to 35 years).

112 EMA collection points (2 assessments per day/ 56 days).

Primary outcomes were craving and urge to use opioids, pain intensity, and affective state. The secondary outcome was event contingent craving.

MORE participants reported greater decreases in several categories including: opioid wanting (44% decrease), opioid urge (50% decrease), pain unpleasantness (13% decrease), and stress (26% decrease). Event-contingent EMA showed MORE participants to report a greater number of cravings (n = 303) than participants in TAU (n = 87). Yet, those cravings were reported as being significantly less intense than those experienced by participants in TAU. Participants in MORE had 68% less severe opioid wanting and 56% weaker opioid urges than participants in TAU.

The daily response rate to random EMA probes over the two months of the intervention was 62%.

 Garland et al., 2019 [52]

MORE: 8, 120-min sessions.

Active Support Group (SG): 8, 120-min. Client-centered group format that facilitated emotional expression and discussion of topics pertinent to chronic pain and opioid use/misuse.

135 individuals recruited from primary care and pain clinics in Salt Lake City, UT (Sample 1 = 40, Sample 2 = 31, Sample 3 = 64). 55.4 (11.1), 57.8 (11.3), 56.7 (10.9) years old respectively per sample.

57.5, 12.9, and 65.6% female. 90, 80.6, and 82.8% non-Hispanic White.

Average duration of opioid use, 10.13 (7.17) years

Baseline and post-intervention.

Experiment 1 assessed the effects of treatment on LPP indices of opioid cue-reactivity relative to reactivity to neutral cues.

Experiment 2 assessed the effects of treatment on the capacity to down-regulate the LPP response to opioid cues. Experiment 3 assessed the effects of treatment on the capacity to up-regulate the LPP response to natural reward cues. Experiment 4 evaluated affect ratings in response to natural reward cues collected from a sample of opioid-treated chronic pain patients participating in a stage 2 RCT of MORE.

For experiment 1, within-group comparisons indicated that SG participants’ post-treatment LPP activations remained higher in response to opioid cues compared to the neutral cues, suggesting an opioid cue-reactivity. Relative to those in the SG, participants who were treated with MORE exhibited significantly greater decreases in the LPP response to opioid cues during regulation (regulate < view) from pre-treatment to post-treatment. MORE participants showed significantly greater increases in LPP response to natural reward cues during regulation from pre-treatment to post-treatment. Relative to those in the SG, participants who were treated with MORE exhibited significantly greater positive affective responses to natural reward cues from pre-treatment to post-treatment.

The study was not a clinical trial powered to detect changes in treatment outcomes.

 Price et al. 2019 [23]

MABT: 8, 90-min sessions.

TAU: Group sessions 2- 3x/week for 10–14 weeks, individual counseling at least 1x/month. Included education about alcohol and drug use and participation in self-help groups (e.g., 12-step) for SUD. Women’s health education (WHE): 8, 90-min group sessions. Included topics such as understanding the female body, reproductive health, cardiovascular health, and sexually transmitted diseases.

Women (MABT = 93 initially, 74 included in analyses; WHE = 56 initially, 46 included in analyses; TAU = 68 initially, 67 included in analyses) recruited from outpatient SUD treatment programs who were currently enrolled in intensive outpatient treatment. Median age of 35 years, 75% non-Hispanic white.

Baseline and 3-month post-baseline follow-up

Substance use outcomes were % of days abstinent and a binary indicator of relapse (TLFB, urine drug screen, electronic health records) and craving (PACS). Mindfulness outcomes were interoceptive awareness (MAIA) and mindfulness (FIM). Psychiatric distress outcomes were DERS, psychophysiological response to a stressful video, rumination, and body awareness (Respiratory Sinus Arrhythmia; RSA), BDI-II, and PSS-SR. Also assessed patient satisfaction.

Participants who received MABT or WHE, compared with TAU, showed significantly greater improvement in the proportion of days abstinent; however, there were no significant differences across groups in relapse or craving. MABT produced significantly greater improvements in mindfulness, as compared to the control conditions, in analyses including individuals who attended 6+ groups, but not in intent to treat (ITT) analyses. MABT was associated with greater improvements in 6/8 MAIA subscales, as compared to the control conditions. MABT was associated with improvements in DERS scores and RSA during the film reactivity task, the body awareness reactivity task, and (in analyses of those who completed 6+ groups) resting RSA, as compared to the control conditions. As compared to control conditions, MABT was associated with greater improvements in BDI-II scores among those who completed 6+ groups, but was not associated with improvements in BDI-II or PSS- SR scores in ITT analyses. 72% of MABT and 63% of WHE participants endorsed highly positive treatment satisfaction ratings of “very much” or “extremely.”

Only examined short- term follow-up.

Findings might not generalize to men.

 Price et al. 2019 [53]

MABT: 8, 90-min sessions.

TAU: Group sessions 2-3x/week for 10–14 weeks, individual counseling at least 1x/month. Included education about alcohol and drug use and participation in self-help groups (e.g., 12-step) for SUD. Women’s health education (WHE): 8, 90-min group sessions.

Reported above.

Baseline, 3-, 6-,and 12-month follow-up.

The primary outcome was days abstinent from substance use (TLFB). Secondary outcomes included measures of emotion regulation (DERS), craving (PACS), psychological distress (PSS-SR and BDI-II), mindfulness (FMI), and interoceptive awareness (MAIA), respiratory sinus arrhythmia (Tonic RSA).

Primary Outcome: The ID sample showed a significant difference between groups. MABT & WHE PDA > TAU at 6 months, MABT > TAU at 12 months. MABT improvements maintained the increased level while WHE & TAU decreased over time. No differences between MABT and WHE at any time point. Secondary Outcomes: Self-report emotion dysregulation had no significant difference at any time point in ID and ITT analysis. Craving: overall ITT & ID showed significant improvements at 6- and 12-months. Psychological distress. No longitudinal difference in mindfulness. Overall significant difference in ID sample with increases in mindfulness skills at 3- and 6-months. Interoceptive awareness. Overall, a significant difference in ITT and ID samples at 3- and 6-months.

Low generalizability due to the low SES of participants, and the fact that all members were women. Study is re-reporting some results with an added time point.

 Spears et al., 2017 [26]

MBAT: 8, 120-min group sessions.

CBT (Manualized): 8, 120- min group session treatment for smoking cessation. Quit day scheduled for Session 5. UC: 4, 5–10 min counseling sessions. Intended to be equivalent to typical support from a health care provider.

Content emphasized problem solving and coping skills training. Quit day scheduled for Session 3.

412 adults who were current smokers (average 5+ cigarettes per day for the past year), motivated to quit within 30 days. 54.9% female, 48.2% African-American, 41.5% non-Latino white. Mean age not reported.

Baseline, treatment weeks 3–8, 26- week follow-up

Smoking cessation outcomes were: nicotine dependence (HSI), smoking dependence and smoking withdrawal ((WISDM) and (WSWS)), smoking avoidance self-efficacy (SES), and attentional bias toward cigarettes(SBQ).

Behavioral outcomes were: affect (PANAS), Depression symptoms (CES D), Stress (PSS), and expectations (AIPQ).

Participants in the MBAT condition perceived greater volitional control over smoking and lower volatility of anger than CBT and UC. No other significant differences nor significant indirect effects of MBAT vs CBT. Participants in the MBAT condition reported lower anxiety, attentional bias, concentration difficulties, craving, smoking dependence motives and higher self-efficacy for negative affect relative to UC.

There was a heavy reliance on repeated administration of self- report questionnaires with significant time lapses between assessments.

 Vidrine et al., 2016 [25]

MBAT: 8, 120-min group sessions.

CBT (Manualized): 8, 120-min group session treatment for smoking cessation. Quit day scheduled for Session 5.

UC: 4, 5–10 min counseling sessions. Intended to be equivalent to typical support from a health care provider.

Content emphasized problem solving and coping skills training. Quit day scheduled for Session 3.

412 adults, current smokers (average 5+ cigarettes per day for the past year), motivated to quit within 30 days. 54.9% female, 48.2% African-American, 41.5% non-Latino white. Mean age not reported.

Baseline, post-treatment, 26-week follow-up

Nicotine dependence (HSI), self-report average days using mindfulness techniques, and smoking abstinence was biochemically confirmed.

MBAT participants reported the highest percentage of 7-day point prevalence abstinence, but not a significant difference. Among participants classified as smoking at final tx sessions, recovery of abstinence was examined. MBAT condition had significantly higher recovery than CBT (Cohen’s d = .88) and UC (Cohen’s d = .79)

The same therapists delivered all treatments.

No assessment of fidelity

 Kober et al. 2017 [16]

MTS: 8, 90-min sessions over 4 weeks.

Freedom From Smoking (FFS): 8, 90-min sessions over 4 weeks. Topics included cognitive strategies for coping with cravings and stress/negative emotions, behavior modification, and relapse prevention.

23 adults (MT = 11, FFS = 12) who smoked > 10 cigarettes/day, had fewer than 3 months of abstinence in the previous year, and were interested in smoking cessation. All participants were part of a larger trial comparing MT and FFS and participants included in the present analysis represent a subset who completed a neuroimaging task. 69.6% male, 48.3 (7.0) years old, 60.9% non-Hispanic white.

Baseline, post-treatment, and 3-month post-treatment follow-up.

Smoking outcomes were reductions in average cigarettes/day from pre- to post-treatment (TLFB).

Also examined fMRI and self-reported stress reactivity and craving to stress/negative scrips and neutral/relaxing scripts.

Those in both conditions reduced smoking (cigarettes/day), but the MT group showed greater reductions during treatment and at the 3-month post-treatment follow-up. The MT and FFS groups did not differ in their self-reported stress or craving to stressful/negative scripts at the post-treatment fMRI session and there were no significant group differences in brain activity during neutral scenarios. Participants in the FFS group (vs. MT) exhibited increased neural reactivity in several brain regions during the stressful scripts. The MT group did not demonstrate greater neural reactivity in any region. Lower reactivity in several brain regions during stressful scripts in the MT condition (vs. the FFS condition) was associated with a greater reduction in smoking after treatment and at 3-month follow-up.

Small sample size. Only completed fMRI post-treatment, and therefore could not assess reductions in neural stress reactivity.

 Black et al., 2019 [17]

Residential SUD treatment program + MMWR: 12, 80- min sessions delivered twice weekly. MMWR was delivered across 6 weeks (as opposed to the standard 12) to better fit the residential site clinical services structure. The residential program included: mental health and SUD diagnosis and treatment (individual and group), trauma education and support, vocational training, nutritional education and support, health and wellness activities, and 12-step meetings, among other services.

Neurobiology of addiction (NA): 12, 80-min group sessions delivered twice weekly. Topics included: definition of addiction and why it is a brain disease; brain structures and functions and those related to addiction; effects of various types of substances on the brain; rewarding effects of substances and how these effects lead to addiction; definitions and brain functions related to craving and withdrawal; and the roles of treatment in recovery.

200 female patients (MMWR- 100, NA-100) at a residential SUD treatment facility. 32.5 (9.1) years old, 21.0% non- Hispanic White, 46.5% had less than a high school education, 62% had been incarcerated in the 8 months prior to residential treatment entry, and 76% were amphetamine/methamphetamine- mine users

Baseline and post-intervention assessment of the self-report measures. 150-day cap (beginning on the first day of the intervention) for discharge status (completer, non- completer with satisfactory progress, non- completer without satisfactory progress, in- residence).

The primary outcome was discharge status and days until discharge. Secondary outcomes were self-report measure scores of study intervention mechanisms of action: mindfulness (FFMQ-SF), perceived stress (PSS-10), distress tolerance and emotion regulation (DERS), distress (DASS-21), affect (PANAS), and drug and alcohol craving (PACS).

The hazard ratio for retention was of medium-to-large effect size, suggesting the clinical relevance of adding MMWR to an all-women’s, ethno-racially diverse, SUD residential treatment center. The length of stay in residential treatment from study intervention start date to analytic endpoint (150 days) was 94.4 days. There were 74 treatment completers (43/100 in MMWR, 31/100 in the NA group), 42 women still in residence (15/100 in MMWR, 27/100 in the NA group). There were 84 treatment non-completers, but satisfactory progress was made by 16/42 women in the MMWR group and 10/42 women in the NA group. For the ITT, risk of non-completion without improvement was lower in MMWR as compared to the NA group after the study intervention. At post-intervention, all eight secondary outcome measurements had improved for both groups.

It is possible that the control curriculum was equally beneficial to some self-reported measures of therapeutic change, which was evident for significantly improved scores in both groups for the FFMQ, DTS, DERS, and PACS.