Megan Per, McGill University
Christina Spinelli, McGill University
Isabel Sadowski, McGill University
Emma Schmelefske, McGill University
Leena Anand, McGill University
Bassam Khoury, McGill University

A growing body of research supports the use of mindfulness-based interventions (MBIs) in incarcerated populations; however, treatment effectiveness remains unclear. This meta-analysis of 22 studies (N = 2,265, 75% male) quantified the effectiveness of MBIs in incarcerated populations on key psychological outcomes and criminogenic needs. Results from pre–post studies indicated MBIs had a small to moderate effect on all outcomes, but this was not supported by controlled studies. Studies with older participants, more females, and longer treatment length demonstrated slightly greater effects. Results from pre–post analyses demonstrated significant reductions in psychological outcomes (depression, anxiety, and stress) and criminogenic needs (impulsivity, self-dysregulation, anger, substance use behavior, and attitude). However, only depression and anxiety were significantly reduced in controlled studies. Although findings offer preliminary support of the efficacy of MBIs in targeting psychological health in incarcerated populations, further controlled studies are required to examine criminogenic outcomes and recidivism rates after treatment.

meta-analysis, criminogenic needs, mental health, incarceration, offender treatment

“Incarcerated youth and adults experience significant psychological difficulties, including higher levels of stress, anxiety, and depression compared with the general population. Approximately two out of three incarcerated individuals meet the criteria for a psychiatric diagnosis in both adult and adolescent populations. Although mental health problems are considered the most significant cause of mortality in prison, they remain undertreated. Furthermore, the social and health costs of incarcerated populations include high rates of recidivism, suicide, violence, and substance abuse.” pp.310-311

“…numerous mindfulness-based interventions (MBIs) intended for the general population have been adapted for both adult and youth incarcerated populations to support their mental health and reduce their recidivism rates. However, the effectiveness of MBIs remains unclear and has yet to be quantified. In addition, there is little evidence examining whether trial characteristics (e.g., pre–post or control), program characteristics (e.g., type of intervention, length of treatment or study quality), and participant characteristics (e.g., gender or age) can affect the usefulness of and incarcerated individuals’ response to MBIs. An examination of these potential contributing factors is required to support prison staff in providing MBIs that are targeted and effective at meeting the behavioral needs and mental health of incarcerated populations, as well as potentially reducing their recidivism rates.” p.311

“The developmental contemplative science (DCS) framework suggests that the effectiveness of mindfulness programs and reaction to mindfulness training will change across developmental periods. As such, it is reasonable to assume that this framework may hold in the correctional context when examining the effectiveness of mindfulness training in incarcerated adults compared with adolescents; however, to our knowledge, no existing research has examined the influence of age on the effectiveness of mindfulness training in incarcerated populations. An examination of chronological age in incarcerated settings is warranted to determine whether this factor affects response to mindfulness training. In addition to the potential influence of age on MBIs in incarcerated settings, there is limited understanding of whether gender affects the effectiveness of mindfulness programs for incarcerated individuals. An investigation of potential gender differences in the efficacy of MBIs in incarceration settings would inform both researchers and practitioners on the appropriateness of mindfulness training for males and females in custody.” pp.312-313

“A comprehensive meta-analysis was conducted to elucidate the effects of MBIs on certain criminogenic needs and psychological outcomes in incarcerated populations, as well as enhance our current understanding of how MBIs may confer their benefits upon incarcerated persons. The first objective of this meta-analysis was to quantify the influence of MBIs on psychological outcomes (depression, anxiety, and stress) and key criminogenic needs (anger, self-regulation, impulsivity, substance use behavior, and attitude toward substance use) for people in custody…Thus, our outcome groups of criminogenic needs and psychological outcomes are based on previous literature. Our second objective was to investigate the process outcome of trait mindfulness. The final objective was to explore the impact of intervention type and examine moderator variables (age, study quality, length of treatment, and proportion of females). The current meta-analysis will provide pertinent information on the role of intervention characteristics and individual differences in the effectiveness of MBIs in incarcerated settings.” p.313

“This meta-analysis examined 20 articles (22 total studies) using MBIs in a correctional setting. The results suggest that from pre- to posttreatment, MBIs significantly reduced certain dynamic risk factors and improved psychological health outcomes. However, the controlled studies present an important caveat to the pre- to post findings, as significant results were only found in reducing anxiety and depression. Results from our moderator analyses revealed that when the population was female, older, or when the treatment duration was longer, there was a weak, yet significant and positive effect on overall outcomes. These findings must be interpreted cautiously, given the weak impact of these moderators…future research is needed to examine differing needs of adolescent versus adult incarcerated populations when engaging in MBIs. The impact of treatment duration on outcome is consistent with previous research as cultivating and practicing mindfulness skills is time consuming. With repeated instructions and meditation practices in session, participants may be more equipped to practice mindfulness on their own and may experience more benefits. Future studies should elucidate this effect by comparing different lengths of treatment (e.g., 1- vs. 2-hr-long weekly sessions or four vs. six weekly sessions).”p.323

“The results of this meta-analysis indicate that MBIs may be a potentially promising intervention for incarcerated populations for enhancing emotional health; however, results were inconclusive regarding criminogenic outcomes. MBIs require minimal resources and are relatively easy to implement in existing adjunct correctional programs. Continued research on the long-term effects of MBIs is needed to evaluate the effectiveness of these treatments and to identify the mechanisms that facilitate change.”p.326

“We found that MBIs contributed to large reductions in psychological outcomes of stress, anxiety, and depression in participants in pre–post studies. MBIs yielded the largest effects for attenuating levels of stress and depression. Findings were supported by the controlled studies, which found small-to-medium effects on anxiety and large effects on depression. These results are in line with the current literature demonstrating that MBIs can significantly enhance emotional health. The implications of these findings are significant, given that incarcerated populations face a disproportionately higher prevalence of psychiatric diagnoses and consequently face additional barriers that may hinder their treatment success. These findings may be explained by the cognitive tools offered in mindfulness training, which could serve to decrease emotion-based drives and assist in the management of prison-related stress. However, the included studies failed to investigate follow-up data on psychological outcomes; thus, future research is needed to explore long-term effects of these interventions. In sum, these findings suggest that mindfulness may have the potential to enable higher overall psychological functioning in incarcerated adolescents and adults.”p.323

“Pre–post treatment results found small-to-moderate improvements on combined criminogenic needs (e.g., self-regulation, impulsivity, anger, substance use behavior, and attitude toward substance use) and MBIs had the largest impact on decreasing anger with a moderate effect. However, when solely targeting controlled studies, the results were insignificant. This suggests that the impact of MBIs on criminogenic outcomes is inconclusive. It is widely accepted that (a) an important intervention goal for incarcerated populations is to manage the risk of reoffending and (b) anger, impulsivity, self-regulation, and drug misuse are significant predictors of reoffending. The ability to regulate emotions (e.g., anger) requires a high degree of executive control, and mindfulness has been demonstrated to improve emotional regulation. Thus, mindfulness may facilitate a process through which individuals can gain cognitive control over behavior.”pp.323-324

“The lack of measurement of dispositional mindfulness is a common criticism of the mindfulness literature. Another possible explanation for the small effect is that the mindfulness measures used may not be appropriate for incarcerated populations. According to Himelstein and colleagues (2015), the Mindfulness Attention Awareness Scale (MAAS) item “I find myself preoccupied in the future or past” is considered insensitive toward the intense trauma common in incarcerated populations. Future studies warrant pre–post measurements of mindfulness to ascertain validity in changes in mindfulness levels.”p.324

“We encourage future research to explore whether positive psychological outcomes, such as self-esteem, mindfulness, and self-compassion, serve as mediators of important factors such as recidivism or clinical outcomes. Some research has found that self-esteem mediates the relationship between mindfulness and both depression and anxiety. Thus, individuals who have high levels of dispositional mindfulness may have higher self-esteem, which consequently contributes to a decrease in anxiety and depression. A better understanding of whether the changes in incarcerated participants’ self-esteem, hope, or self-compassion are significant contributors to these positive outcomes is warranted. Future research should explore the potential pathway through which mindfulness exerts a positive effect on incarcerated individuals, as this was beyond the scope of these analyses.”p.325

“As demonstrated by our analyses, there is a danger in relying solely on pre–post outcomes as indicators of treatment effectiveness. Although pre–post studies showed significant effects of mindfulness when examining all outcomes combined, results were not supported by controlled studies alone. We make the following recommendations for future researchers: (a) utilize an active control (e.g., psychoeducation about emotion regulation, relaxation intervention) rather than an inactive control (e.g., wait-list), (b) take measures of mindfulness across the entire intervention (e.g., at baseline and postintervention) and between sessions (e.g., before and after each meeting), (c) quantify and qualify mindfulness practice by asking participants to log how long they practiced and how well they were able to engage in the practice (on a daily basis), (d) include a 3-month or longer follow-up postrelease to obtain information about recidivism, (e) obtain qualitative feedback on the intervention to accurately assess feasibility and satisfaction with the MBI, and (f) the use of the Cochrane handbook to avoid potential sources of bias for RCTs (e.g., allocation concealment, blinding of participants).”p.325

As always, please join the discussion below if you have thoughts or comments to add!