Mindfulness-Based Interventions in Psychiatry

Mindfulness meditation is steeped in centuries of Buddhist practice and philosophy. In the late 20th century, these practices were incorporated into Western interventions to treat physical and mental illnesses. Kabat-Zinn (1) first introduced mindfulness meditative practices to treat chronic pain and developed a program named mindfulness-based stress reduction (MBSR). Subsequently, Segal and colleagues (2) extended the use of mindfulness meditation into psychiatry by developing a treatment program for the prevention of depression relapse that combined cognitive-behavioral therapy and mindfulness techniques and was named mindfulness-based cognitive therapy (MBCT) (2). Since the development of MBSR and MBCT, numerous other mindfulness-based interventions (MBIs) have been developed, and hundreds of research studies have been conducted to examine the efficacy of these programs.

Mindfulness-based programs are designed to train individuals to cultivate mindfulness and incorporate its practice into daily life. Mindfulness has been defined as “paying attention in a particular way, on purpose, in the present moment, and nonjudgmentally” (3). A further conceptualization of mindfulness proposed a two-component model. One component involves self-regulation of attention to the experience of the present moment, and the other involves adopting an orientation of openness and acceptance toward one’s experience (4). Therefore, these interventions teach mindfulness skills to increase intentional attention, to develop a different relationship with one’s thoughts, and to practice different strategies in relation to distressing thoughts and emotions in a nonjudgmental way (5). Through experiential practices and exercises, participants learn to step back or disengage from initial thoughts by creating a meta-awareness (awareness of being aware), which, in turn, counters repetitive negative thinking and increases cognitive flexibility (5, 6).

In the current article, we provide a focused review of interventions that incorporate mindfulness training to treat psychiatric disorders. Although this review focuses on MBCT, as this program was the first mindfulness intervention designed to treat mental health problems (2), we also review other MBIs that have been used with psychiatric populations. We describe how these interventions are implemented and the skills that are taught. Furthermore, we identify the patient populations in which MBIs have been shown to be efficacious and present research support for some mechanisms through which these interventions may work. This review offers a basis for incorporating these interventions into treatment and recommendations for further readings.

Treatment

MBIs

MBIs, including MBSR (1) and MBCT (2), were developed as secular, manualized, group-based intervention programs. These programs generally consist of eight weekly 2- to 2.5-hour classes that carry approximately 12 patients. Additionally, these programs also often include a one-day retreat. A key feature of MBIs is the education in formal and informal mindfulness meditation practices to train both the attentional control component as well as the nonjudgmental attitudinal aspects of mindfulness as described earlier (7).

Formal meditation practices include sitting meditation, mindful movement (including walking medication and gentle yoga exercises), and the body scan, which teaches individuals to mindfully focus on bodily sensations, starting with the feet and progressively moving to the head and neck. The mindfulness meditation exercises focus on paying attention to bodily sensations, emotions, and thoughts while embracing a nonjudgmental, accepting attitude toward whatever arises until it passes (8). MBIs have a significant homework component with guided (often with audio recording) and unguided meditation practices that are assigned as daily home practice. The programs also include informal practices that aim to integrate mindful awareness in everyday activities, such as mindful eating (“the raisin exercise”) and mindful brushing of teeth (9).

In MBCT, the “three-minute breathing space” is a central program element that aims to incorporate what is learned in the formal meditation practices in everyday life. The exercise consists of three steps: becoming aware of thoughts, feelings, and bodily sensations; then bringing attention to the breath; and finally expanding the attention to the body (5). Another important aspect of MBIs is a group-based exploration of individual experiences, referred to as inquiry. During the group discussions, participants share their personal experiences of difficulty and success in practicing mindfulness. Through this discussion, participants learn from one another via modeling and direct feedback. MBI teachers are required to have an ongoing personal mindfulness meditation practice to “embody” the ethical underpinnings and core qualities that are associated with mindfulness (10).

Group-based weekly mindfulness intervention programs such as MBSR and MBCT have the highest level of evidence of clinical efficacy; however, other formats such as retreats, brief mindfulness-based interventions, as well as web-based and smartphone app interventions may also have beneficial effects (11).

Mindfulness-Informed Interventions

Whereas MBIs are programs placing a large emphasis on formal meditation practices to cultivate mindfulness skills, mindfulness informed interventions, such as dialectical behavior therapy (DBT) (12) and acceptance and commitment therapy (ACT) (13), incorporate mindfulness practices as a part of a broader treatment program. These programs additionally use a range of non–meditation-based techniques to promote mindfulness skills using experiential exercises, stories, and metaphors.

DBT is a weekly two-hour group skills-training program that was originally developed to treat borderline personality disorder. This program has subsequently been used for numerous other conditions, including emotional disorders. In addition to the weekly group, this program includes homework assignments as well as individual sessions. It has been suggested that DBT generally takes a wider timeframe of at least one year to be fully effective (12).

Mindfulness is considered the core skill in DBT; it is the first of four skill modules taught in the program and is central to all subsequent skill modules. However, DBT does not require formal mindfulness meditation practice to develop mindfulness skills. Mindfulness skills are taught in DBT to develop the ability to use one’s “wise mind,” a mental state metaphorically placed between the “logical” and “emotional” mind. To do this, DBT group leaders teach mindfulness by focusing on “what” and “how” skills. The three “what” skills include observing, describing, and participating, and the three “how” skills are being nonjudgmental, one-mindful, and effective (14). As described earlier, this delineation fits with the two-component model of facilitating attentional awareness toward the current experience with an open and accepting stance.

ACT is a transdiagnostic intervention that is typically provided in an individual therapy setting; however, it may also be delivered in various formats depending on the therapeutic context (15). ACT uses acceptance and mindfulness strategies to develop committed behavior change by increasing psychological flexibility. Similar to DBT, mindfulness is a core component of the ACT model and one that is focused on early in treatment. ACT practice typically uses real-life examples and metaphors to increase contact with the present moment, with the aim of decreasing rumination on past deeds and worry about future problems. In this way, individuals can then accept their current circumstances.

It is within this focus on and acceptance of the present moment that individuals can implement values-based actions to improve functioning. Mindful acceptance is deemed crucial for treatment effectiveness. The duration of ACT interventions varies considerably, ranging from 12 one-hour individual sessions (16) to as short as 20-minute sessions integrated into primary care visits (17). Different treatment delivery formats, such as individual therapy sessions (18), one-day workshops (19), telephone-delivered therapy (20), a smartphone app (20), and web-based therapy (21), have been used in prior research.

Efficacy

The most widely examined MBI to treat psychiatric disorders is MBCT. This program was developed as a psychosocial intervention for preventing relapse among patients with a history of major depressive disorder (2). There is considerable evidence supporting the use of MBCT to decrease the risk of depressive relapse. Specifically, a recent meta-analysis that included four randomized controlled trials of patients with at least three depressive episodes found that MBCT reduced the risk for relapse and recurrence of major depressive disorder compared with treatment as usual (TAU) or placebo control groups. The relapse rate among MBCT+TAU patients was 32% relative to 60% for the TAU control group (22). Moreover, MBCT has been as efficacious as a maintenance antidepressant medication in preventing major depressive disorder relapse (22, 23).

However, studies that have used active-control groups structurally equivalent to MBCT have provided mixed findings regarding its superiority in preventing relapse (24–26), suggesting that although MBCT may be effective, it may not be superior to other active psychosocial interventions. It has been posited that MBCT may be particularly effective among patients with a history of three or more major depressive disorder episodes who are especially prone to ruminative thinking (27). A meta-analysis found the number of previous depressive episodes to be a significant predictor of outcome (23). Although there was no risk reduction of relapse among patients with two or fewer episodes, the risk of recurrence was reduced by 43% among those with three or more episodes (23).

Further evidence of MBCT on the treatment of depression relapse and active depression is beginning to develop. Evidence is accumulating to suggest that MBCT is more effective than TAU and active control for those who had experienced childhood trauma (25). Moreover, MBCT may be a particularly viable option for patients who would like to discontinue antidepressant medications (28). In a trial comparing maintenance antidepressant medication and MBCT with support to taper or discontinue antidepressant medication among 424 patients with major depressive disorder and at high risk for relapse (more than two major depressive disorder episodes), there was no difference between the two conditions in relapse rate over 24 months (28). Finally, although MBCT was initially developed for preventing relapse among patients with major depressive disorder, empirical evidence has also shown initial efficacy of MBCT for current major depressive disorder (29). These studies have shown improvement in symptoms among patients with current depression (29, 30).

Although MBIs were not initially developed to treat psychopathology (31), emerging evidence suggests that they may be useful in treating many active psychiatric disorders. Two recent meta-analyses found that MBIs are helpful in reducing current mood and anxiety symptoms among patients with anxiety and mood disorders (30, 32). Additionally, several studies have shown preliminary evidence of the effect of MBIs with patients with bipolar disorder (33), obsessive-compulsive disorder (34), and generalized anxiety disorder (35). Preliminary support also exists for MBIs to treat eating disorders. Specifically, multimodal MBIs appear effective, whereas brief interventions may not be beneficial in treating anorexia nervosa (36). Similarly, preliminary support evidence suggests that MBIs may be efficacious in treating obesity-related eating behaviors, such as binge eating, emotional eating, and external eating (37). Finally, a treatment program called mindfulness-based relapse prevention (38) was developed drawing from selected components of substance use disorder relapse prevention (39, 40) and from MBSR and MBCT. Mindfulness-based relapse prevention may be successful in reducing both substance use and craving (41); however, a meta-analysis did not detect statistically significant differences between mindfulness-based relapse prevention and comparators on relapse, frequency of use, and treatment dropout (42).

The use of MBIs in the treatment of current psychiatric disorders is relatively new and should be considered preliminary in nature (43). Research to-date indicates that MBIs may be effective at treating a wide range of psychiatric disorders; however, there are several limitations to consider. Most of these studies generally do not have a comparison condition, and if they do, they use a waitlist control or TAU comparison group. Although this is an important first step, we do not yet know whether improvements are due to time or to attention from a mental health practitioner or whether they are specific to the skills taught in MBIs. In addition, the inclusion criteria of these studies focus on the specific disorder of interest and exclude co-occurring disorders that may influence findings, which are less generalizable to the clinic.

To have stronger claims that MBIs could be used as a frontline intervention for psychiatric disorders (44), well-powered studies that use a randomized controlled trial with an active comparison are needed. Following these needed efficacy studies, the effectiveness of MBIs in clinical setting that includes common comorbid conditions are important because of the high rates of co-occurring disorders. Additionally, samples that include patients from more racially-ethnically and economically diverse backgrounds are important for widespread dissemination. Taken together, MBIs are promising interventions because they appear to be beneficial across psychiatric disorders. However, although the efficacy of MBCT to reduce major depressive disorder relapse is well-established, more well-designed studies in the treatment of active disorders are needed.

Mechanisms

As described earlier, MBIs have been shown to be efficacious at reducing the risk of depression relapse and reducing symptoms among patients across multiple psychiatric disorders. However, these efficacy trials do not indicate how these interventions lead to symptom resolution. Considering the support for MBI, researchers have begun to examine the mechanisms that may lead to symptom change in the context of these interventions. These investigations include the examination of psychological, cognitive, and neural mechanisms, which are reviewed next.

Cognitive and Psychological Mechanisms

Individuals with recurrent depression are particularly vulnerable to depressogenic cognitions (45). Stressful life events or other triggers in everyday life may give rise to well-rehearsed negative thinking patterns such as depressive rumination, worry, and self-criticism, which, if persistent, may escalate to depressive relapse or other psychiatric symptoms. The theoretical model on which MBCT is based (2) emphasizes identifying these thinking patterns as they arise and viewing them as temporary mental phenomena rather than as facts or realities to be identified with or reacted to (a process referred to as meta-awareness, sometimes used interchangeably with decentering) (2, 45).

Coupled with an accepting, nonjudgmental, and nonreactive attitude, these processes are viewed as key mechanisms that contribute to “loosening the grip” of the negative thinking patterns. Research has largely supported this notion and has shown that these processes are central components and active ingredients of MBCT. Following MBCT training, participants exhibit improved self-reported mindfulness (46–53), reduced rumination (46, 48–51, 54–56) and worry (46, 50, 56), improved meta-awareness (55, 57, 58), increased self-compassion (59, 60), and reduced emotional reactivity (61). Moreover, these improvements at least partially mediated or predicted the effect of MBCT on treatment outcome (for reviews, see 45, 62, 63), with the strongest effects found for mindfulness, rumination, worry, and emotional reactivity.

The vulnerability of individuals with recurring depression to have depressogenic cognition is additionally exacerbated by impaired cognitive functioning and diminished cognitive resources. These individuals often exhibit overgeneral autobiographical memory (a difficulty in retrieving specific personal events), impairments in attention regulation, and difficulties suppressing competing or currently-irrelevant thoughts and mental sets, among other cognitive deficits (64–69). Research indicates that MBCT may attenuate these symptoms. MBCT has been shown to reduce overgeneral autobiographical memory (58, 70, 71), improve attention deployment and maintenance during sad mood (72), and reduce attentional-bias toward negative emotional stimuli (47), although such attentional improvements are not ubiquitous (45, 51, 73).

MBCT has additionally been shown to augment suppression of currently irrelevant mental sets (74) and to promote both cognitive flexibility and overall cognitive functioning (Shapero BG, Greenberg J, Mischoulon D, et al., submitted manuscript, 2017), benefits that correlate with a reduction in depressive symptomology. Studies examining other MBIs with healthy participants similarly indicated improvements in cognitive abilities, such as working memory (75, 76), cognitive flexibility (77, 78), and inhibition (79), with very limited evidence regarding attentional improvements (for a review, see 73). Although the specific impact of these cognitive improvements has yet to be established, such cognitive faculties are important factors in facilitating the disengagement from negating thinking patterns associated with depression and may be vital in addressing the cognitive deficits associated with numerous clinical conditions.

Importantly, much of the research on the mechanisms through which MBIs work has been focused on the treatment of depression or depression relapse. However, many of the potential psychological mechanisms cut across disorders. That is, the mindfulness training and skills taught in MBIs are not necessarily aimed at one psychiatric phenomena or condition but are rather focused on modifying processes that potentially underlie many psychiatric disorders. For example, perseverative cognitions such as worry and rumination occur in many forms of psychopathology, including mood and anxiety disorders, eating disorders, and obsessive-compulsive disorder (80). MBIs attempt to train individuals to develop a different relationship with their thoughts by developing the skill to notice one’s thoughts and then practice different strategies to distance oneself from these thoughts. In this manner, the mechanisms through which MBIs reduce symptoms are through meta-awareness, altering one’s perspective of the self, and self-awareness as some examples (81–86).

Another transdiagnostic mechanism through which MBIs may work is through enhancing emotion regulation strategies. Emotion regulation deficits, or emotion dysregulation, occur across psychiatric disorders (87). Through repeated meditation practices, MBIs develop body awareness, self-regulation, and emotion regulation skills (81–86). The nonjudgmental stance conveyed across MBIs allows participants to recover from one’s emotional state more quickly and increases the flexibility through which one can respond to stressful events (76). Finally, numerous other transdiagnostic mechanism models include self-transcendence, exposure, relaxation, nonattachment, ethical practice, and clarification of values (81–86).

Neural Mechanisms

The effects of mindfulness and meditation training on the brain have been investigated in more than 100 brain imaging studies, which can be divided into two categories: structural and functional. Structural brain imaging, typically with magnetic resonance imaging, provides a high-resolution, three-dimensional image of the brain from which various features of brain anatomy can be quantitatively measured, such as cortical thickness, volume of various subcortical areas, degree of gyrification, and so forth. Functional brain imaging instead measures brain function, or brain activation, over time during a specific task or prescribed state (“resting state”). These two methods provide distinct yet complementary information about the brain, and both have been used to assess the effects of meditation on the brain.

Structural brain imaging.

Early studies used a cross-sectional design to compare individuals with long-term meditation experience (“meditators”) with individuals without meditation experience; these participants were matched for age, gender, education, and other relevant variables. Fox and colleagues (88) systematically reviewed this literature and conducted a meta-analysis of 21 neuroimaging studies that examined roughly 300 meditation practitioners. They found that eight brain regions were consistently altered in meditators, including areas associated with meta-awareness (frontopolar cortex-Brodmann area 10), exteroceptive and interoceptive body awareness (sensory cortices and insula), memory consolidation and reconsolidation (hippocampus), self- and emotion regulation (anterior and mid cingulate; orbitofrontal cortex), and intra- and interhemispheric communication (superior longitudinal fasciculus; corpus callosum), with a global “medium” effect size (88).

Although the above cross-sectional comparisons were intriguing, they could not prove that meditation training caused the observed changes. Indeed, it could have been the case that meditators possessed distinct features of brain anatomy for reasons other than meditation (genetic, environmental). Therefore, the most compelling evidence for the effects of mindfulness meditation training on the brain comes from longitudinal studies, in which participants are evaluated at multiple time points as they engage in meditation training (preferably starting before their first exposure to meditation).

For example, Hölzel and colleagues (89) reported a pre-post increase in gray matter concentration within the hippocampus, the posterior cingulate cortex, the temporo-parietal junction, and the cerebellum after a standard eight-week MBSR course in healthy participants who were stressed (89). They also found that participants reported significant reduction in perceived stress that correlated positively with decrease in gray matter density in the right basolateral amygdala (90). These various brain regions have been associated with learning and memory processes, emotion regulation, self-referential processing, and perspective taking. However, it has not been investigated whether the structural changes corresponded to behavioral functional changes; therefore, these findings should be interpreted with caution.

The structural changes observed longitudinally after MBSR did not involve the same brain regions as those observed cross-sectionally between long-term meditators and matched control participants. Therefore, it is too early to draw firm conclusions regarding the effects of meditation on brain structure.

Functional brain imaging.

The effects of mindfulness meditation practices on brain function have been more broadly studied than their effects on brain structure. However, the picture to date is more complex in the evidence of functional changes compared with those of structural changes. Across studies, meditators have been asked to perform a great variety of tasks while receiving a functional magnetic resonance imaging scan, spanning such varied domains as cognitive (attention, memory, executive function), affective (emotion regulation), and of other self-related processes (rumination).

A recent review analyzed 78 functional neuroimaging (functional magnetic resonance imaging and positron emission tomography) studies of meditation and used activation likelihood estimation to conduct a meta-analysis of 257 activation peak locations from 31 experiments involving 527 participants (91). This meta-analysis covered various meditation practices, which the authors categorized into four main types (focused attention, mantra recitation, open monitoring, and compassion-loving-kindness meditation) and three additional types that have been less studied (visualization, sense-withdrawal, and nondual awareness practices). The authors found several brain areas to be recruited consistently across multiple types of meditation practice: insula, presupplementary and supplementary motor cortices, dorsal anterior cingulate cortex, and frontopolar cortex. However, the authors concluded that “convergence is the exception rather than the rule” (91).

In conclusion, more studies are needed to determine specific neural changes attributable to mindfulness meditation, especially in clinical populations that are increasingly receiving meditation-based interventions, with growing evidence of efficacy, especially for anxiety, depression, and pain (reviewed in 92). In line, different types of meditation practices may influence different brain structures. It is important to carefully and consistently define the type of meditation practices studies because this may influence interpretations and consolidation of the literature examining the effects of mindfulness on neural changes. It is also important that future studies use a hypothesis-driven approach in which specific functions are tested both behaviorally and neurally.

Conclusion

Although mindfulness practice has a longstanding history, it is only since the late 20th century that mindfulness interventions have been incorporated into Western medicine. Despite this relative short history, MBIs have garnered considerable support for their efficacy to treat psychiatric disorders. Numerous research investigations have shown that MBIs are efficacious for reducing depression relapse and treating depression symptoms. In addition, these interventions reduce symptoms across psychiatric disorders with mounting support for anxiety disorders, bipolar disorder, eating disorders, and substance use disorders.

Although we know much about the patient populations that may benefit from receiving mindfulness training, we do not yet know for whom MBI treatment may work best. With a movement toward more personalized care, it is important to identify for whom these interventions may work best. For example, some research has shown that those with a chronic history of depressive episodes may benefit the most from MBCT; however, there are many other factors that may contribute to optimal clinical outcomes. Further work is needed to give clinicians a better understanding of the best candidates for MBI and when to refer for treatment. Much work is still needed to enhance the understanding of MBIs so that they may have a broad public health impact (93).

Research has also provided evidence for the mechanisms on how MBIs improve psychological health. MBIs have been shown to increase positive psychological attributes, such as mindfulness, meta-awareness, and self-compassion. In addition, MBIs have been shown to reduce negative thinking patterns and reactions associated with psychopathology, such as rumination, worry, and emotional reactivity. Furthermore, mindfulness interventions may reduce cognitive deficits that are associated or a result of psychiatric disorders, such as overgeneral autobiographical memory, poor attention regulation, and cognitive rigidity. Mindfulness meditation may also be associated with neural changes. Some research supports the association of structural and functional differences between those who meditate and those who do not. However, further research is needed to establish a direct causal model associated with brain changes with MBIs.

Although the efficacy of MBIs has been extensively studied, further work is needed to integrate these interventions into standard practice. Additionally, limited studies have examined the effectiveness of MBIs in real-life settings (93) and how best to disseminate these efficacious interventions into the community. A key issue in this regard is the training of practitioners in empirically supported MBIs. Furthermore, although mindfulness interventions may reduce psychiatric symptoms on their own, it is less clear whether they can serve as an adjunctive treatment to current psychotherapy or psychopharmacological interventions. It is likely the case that these group-based programs can be added to standard care; however, research is needed to make strong recommendations for providers. In sum, the science and practice of MBIs have proven to have clear benefit among those with psychiatric disorders. The field is at a stage in which the decades of research in this efficacy need now turn to effectiveness trials to make a broad impact and integration in health care.