The Effects of Mindfulness and Buddhist Meditation Coaching on Mental Health Outcomes in College Students

College students are vulnerable to diverse mental health disorders. We aimed to investigate whether a meditation class would be an effective means to address students' mental health challenges. Among the college students who registered for the meditation course, 256 participants were enrolled. The meditation course was a 15-week program incorporating mindfulness meditation and Ganhwa Seon (a traditional Buddhist meditation). A questionnaire was administered twice, on the first and last class of the course, collecting information on personal characteristics and six mental health indicators. A paired t-test was used to examine whether the meditation course conferred benefit on the mental health indicators, and logistic regression analyses were run to identify factors associated with mental health outcomes. After completing the meditation course, there were significant improvements for the adult ADHD score (p < 0.01) and ego identity (p = 0.02) but not for the other outcomes. Among college students, meditation practice may have positive effects on the adult ADHD score and ego identity.


Introduction
College students, undergoing the transition from adolescence to adulthood, are exposed to unique stressors [1]. In addition to academic pressure, college students are expected to take on adult responsibilities in fnancial support, personal relationships, social engagement, etc. [2]. Encountered with such stressors, many college students face mental health challenges, with the rates of mental illness rising on college campuses [2]. Tus, colleges and universities try to fnd ways to address the mental health crisis among students. One potential intervention may include mindfulness meditation, the most popular meditation practice in the West. Originating from Buddhist teachings, mindfulness meditation is a mental training framework to cultivate awareness of what one is sensing and feeling in the moment through nonjudgmental observation [3].
A previous study comprising a systematic review of randomized controlled trials indicated that mindfulness meditation could be associated with the regulation of the immune system, for instance, the decrease in proinfammatory processes or the elevation in cell-mediated defense systems [3]. Tough there is a certain level of difference depending on the level of trait mindfulness, another study of college students showed that the anxiety state decreased as the mindfulness state increased and that was an improvement in attention and executive function performance [4]. Also, a separate study conducted with 152 Taiwanese university freshmen over the course of a semester-long mindfulness meditation course found improvements in learning efectiveness as well as the cognitive performance of attention and memory [5].
Of note, referred to as Ganhwa Seon, it represents the mainstream of meditation within Korean Buddhism [6]. Ganhwa Seon involves raising a specifc question, termed "hwadu," and directing one's full attention to the question in daily life to get deeply absorbed in the single-mindedness of questioning [6]. While mindfulness meditation is widely accepted by people regardless of one's religion and culture, as well as transnationally, the practice of Ganhwa Seon is often limited to Buddhists in Korea. At Dongguk University in Korea, as a Buddhism-based university, students are required to take a meditation course, in which Buddhist spiritual leaders guide students to practice mindfulness meditation and Ganhwa Seon. In this study, among college students, we aim to investigate whether meditation practice performed as class activities afects six mental health outcomes. (1) Adult attention-defcit hyperactivity disorder (ADHD): inattention, hyperactive-impulsive symptoms, or their combinations [7]; (2) ego identity: the sense of self to experience who they are [8]; (3) perceived stress: the extent to which individuals perceive their life circumstances to be stressful, unpredictable, and uncontrollable [9]; (4) self-effcacy: individual confdence in the ability to take required actions to fulfll specifed objectives [10]; (5) self-esteem: diverse and intricate mental states related to self-perception [11]; and (6) spiritual well-being: the intrinsic sense of contentment [12].

Study Participants.
We recruited students who registered for a meditation course at Dongguk University in Seoul, Korea, in 2018. Initially, 305 subjects were recruited for the study participants. We excluded individuals with missing information on the frst questionnaire (n � 22), the second questionnaire (n � 25), and/or covariables (n � 2). After these 16% exclusions, the fnal analytic sample included 256 participants (133 males and 123 females). Missing data were defned as the absence of responses to at least one of the mental health questionnaires (Figure 1).
Te researcher gave participants a full explanation of the research purpose before enrollment, and consent to participate was obtained voluntarily. Tis study was approved by the Dongguk Institutional Review Board (IRB number: DUIRB-201810-13).

Data Collection.
Participants responded to a questionnaire twice during the frst and last classes of the meditation course. Te questionnaire collected information about personal information (e.g., age, sex), grade (i.e., students' academic year at the time of course registration), major, adjusting to college life, socioeconomic status, religion, knowledge of Buddhism, the importance of religion in life, and six mental health indicators (adult ADHD, ego identity, perceived stress, self-efcacy, self-esteem, and spiritual wellbeing).
Te adult ADHD score was assessed by the Korean version of the Conners adult ADHD rating scale-26 items, a 26-item instrument developed to measure the presence and severity of ADHD symptoms in adults [13]. Each item was rated on a 4-point scale from 1 (never) to 4 (almost always), and the composite score can range from 26 to 104, with higher scores indicating higher levels of ADHD.
Ego identity was assessed by the ego-identity scale instrument, which was developed in Korea to measure various aspects of ego identity [14]. Te scale consisting of 48 items, covers areas of independence, self-acceptance, future certainty, goal orientation, proactive personality, and intimacy. Each item was rated on a 5-point scale from 1 (never) to 5 (almost always), and the composite score can range from 48 to 240, with higher scores indicating higher levels of ego identity.
Perceived stress was measured by the Korean version of the perceived stress scale, a 10-item instrument developed to assess the degree to which situations in one's life are appraised as stressful [15]. With each item rated on a 5-point scale from 1 (never) to 5 (almost always), the composite score can range from 10 to 50, and higher scores indicate higher perceived stress.
Self-efcacy was measured by the new general selfefcacy scale, an 8-item instrument designed to measure the degree of a person's belief in one's ability to achieve one's goal despite difculties [16]. With each item rated on a 5point scale from 1 (never) to 5 (almost always), the composite score can range from 8 to 40, and higher scores indicate higher self-efcacy.
Self-esteem was measured by the Korean version of the Rosenberg self-esteem scale, a 10-item instrument designed to assess positive and negative feelings about the self [17]. With each item rated on a 4-point scale from 1 (never) to 4 (almost always), the composite score can range from 10 to 40, and higher scores refect higher levels of self-esteem.
Spiritual well-being was measured by the Functional Assessment of Chronic Illness Terapy-Spiritual Well-Being, a 12-item questionnaire designed to measure spiritual well-being in people with cancer and other chronic illnesses [18]. With each item rated on a 5-point scale from 1 (never) to 5 (almost always), the composite score can range from 12 to 60, and higher scores refect higher well-being.

Statistical Analysis.
To understand the characteristics of the study population before the start of meditation classes (i.e., at baseline), we calculated proportions for categorical variables and mean and standard deviation for continuous variables. Evidence-Based Complementary and Alternative Medicine To evaluate whether mental health outcomes (adult ADHD, ego identity, perceived stress, self-efcacy, self-esteem, and spiritual well-being) changed signifcantly after meditation classes in a one-grouppretest-posttest design, we used the paired t-test. A parametric test was chosen based on the central limit theorem, which states that the sampling distribution of differences approximates a normal distribution when the sample size is above 30 [19]. In general, individuals respond diferentially to meditation classes. By defning change in outcome scores as a binary variable (1: improvement in scores; 0: no improvement in scores), we performed a multivariable logistic regression analysis to calculate the odd ratios (ORs) of the improvement P case /(1 − P case ) ∕ P control /(1 − P control ) * P � probabilities of event occurrence to identify factors associated with improvements in spiritual and mental health outcomes. Te levels of the outcome variables were defned as 1 for individuals who showed improvement after meditation classes and 0 for those who did not show any improvement. Te models were adjusted for the baseline characteristics (i.e., sex, grade, major, college adaptation, socioeconomic status, religion, degree of knowledge of Buddhism, degree of importance of religion in life, and instructors) as well as the level of the outcome before the start of the medication class.
p value less than 0.05 is considered statistically signifcant. All statistical analyses were performed using SAS 9.4 (SAS Institute, Cary, NC, USA).
While the fnal sample was not determined based on a priori power calculation, based on a post-hoc power calculation setting α error rate at 0.05, our study has 89% power to detect a mean diference of 1 in the outcome score (standard deviation of the diference: 5).

Results
Te characteristics of the 256 participants are presented in Table 1. Te study population was almost equally divided by gender. Approximately 46% and 30% of participants were freshmen and sophomores, respectively. Te number of students in the College of Science was the highest, and the number of students in the College of Humanities and Social Sciences was the next. About 12% of participants were Buddhists, and 88% were Christians, believers of other religions, or atheists. Most of the participants had little or fair knowledge about Buddhism, and about 41% of students answered that religion had no efect on their lives.
Individuals benefted from the meditation class diferentially with regard to adult ADHD score change and ego identity ( Table 2). For a change in adult ADHD score, students were more likely to improve their adult ADHD score after the meditation class when they had a higher ADHD score at baseline (OR 1.05, 95% CI 1.03-1.08, p < 0.01), in college of education (OR 3.58, 95% CI 1.25-10.23, p � 0.03), and had a better adaptation to college life (OR 2.04, 95% CI 1.05-4.00, p � 0.04) at baseline. For ego identity, students were associated with an increased ego identity after the meditation class when they had a lower ego identity at baseline (OR 0.98, 95% CI 0.96-0.99, p < 0.01), male sex (OR 3.04; 95% CI 1.66-5.59, p < 0.01), in college of education (OR 5.48, 95% CI 1.70-17.63, p < 0.01), and of Buddhist (OR 2.58, 95% CI 1.00-6.61, p � 0.05) at baseline.

Discussion
In this study of 250 university students, we investigated the efect of practicing mindfulness meditation and Ganhwa Seon as class activities on six mental health outcomes (adult ADHD, ego identity, perceived stress, self-efcacy, selfesteem, and spiritual well-being).
We observed that in-class meditation practice conferred statistically signifcant improvements in adult ADHD scores and ego identity. Notably, the benefcial efects of the Evidence-Based Complementary and Alternative Medicine meditation class on these two outcomes varied by several baseline characteristics. For a change in adult ADHD score, students were more likely to beneft from the meditation class when they had a severe adult ADHD score, were from a college of education, and were better adapting to college life; for ego identity, students were more likely to beneft when they had a lower ego identity, were of the male sex, were from a college of education, and were Buddhists. Upon completing the meditation course, perceived stress, selfefcacy, self-esteem, and spiritual well-being changed positively, but the improvements were not statistically signifcant.
Adult ADHD is a psychiatric condition suggested to be caused by a complex combination of genetic and environmental risk factors [20]. Its major symptoms include difculties with initiating work, self-organization, and prioritization; varying levels of attention to details; and poor persistence in work requiring continuous mental eforts [21]. Consistent with our fndings, previous studies have shown that mindfulness meditation improves adult ADHD scores. In a study of 24 adults and 8 adolescents in the US, an 8-week mindfulness training program resulted in improvements in self-reported ADHD symptoms [22]. In another study conducted among Taiwanese university students, students who took a one-semester mindfulness meditation course showed improvements in cognitive attention and memory compared to control students who did not take the meditation course [5]. According to neuroimaging studies, the anterior cingulate cortex has been implicated in several cognitive functions, including attention [23,24], and meditation practice was shown to activate the anterior cingulate cortex practice, contributing to attention maintenance [24,25]. In addition, cortical thickness, whose reduction is a marker of adult ADHD [26], was higher in the dorsal anterior cingulate cortex among experienced meditators compared with control subjects in anterior cingulate cortex magnetic resonance neuroimaging studies [27].
Ego identity refers to the sense of self that enables individuals to experience a sense of who they are [8]. Previous studies have shown that regular engagement in meditation improved self-knowledge, facilitating individuals to become fully attentive to what is happening without any judgements [28]. In addition, mindful meditation was associated with increased self-acceptance, which in turn helps a foster healthy sense of one's true self [29]. While no previous studies investigated the direct efect of Ganhwa Seon on ego identity, one of the most common questions that is consistently asked during the practice is "who am I" [6], which relates to the pursuit of ego identity. Te benefcial efects of meditation on ego identity are also supported by biological mechanisms. Te prefrontal cortex plays a critical role in higher brain functions, including personality formation [30]. Neuroimaging studies suggested that enhanced activation of the ventromedial prefrontal cortex might promote the development of identity [31]. In a study of healthy older adults, participants who engaged in eight-week meditation training showed enlargements in a prefrontal network involving the ventromedial prefrontal cortex compared with those engaged in control relaxation training [32].
In our study, not all students beneftted equally from the meditation class. For both adult ADHD score change and ego identity, students with worse outcome conditions (i.e., higher adult ADHD score, lower ego identity) at baseline and from the college of education experienced greater improvements after meditation practice, compared with students in their counterparts. Much as nutritional supplements are more likely to beneft individuals with  Evidence-Based Complementary and Alternative Medicine nutrient defciencies than individuals who are nutritionally replete [33], meditation practice may be more efective among individuals experiencing mental health problems and, thus, have more room for improvement than among healthy individuals. In the case of students from the College of Education, due to their major, they tend to have a greater  Ego-identity Perceived stress Self-efficacy Self-esteem Spiritual well-being Adult ADHD Scales Figure 2: Average diferences in spiritual and mental health outcomes before and after meditation class.
Evidence-Based Complementary and Alternative Medicine 5 appreciation for education. Tis mindset and attitude might have motivated these students to exert greater eforts during the meditation class, which in turn led to the greater beneft of meditation. Specifcally, for change in adult ADHD scores, students who reported being well-adjusted to college life were more likely to improve their adult ADHD score after the meditation practice than students who did not. Academic satisfaction is an important determinant of college adjustment, which predicts achievement [34]. In light of this, students with better adjustment to college life might have actively participated in the meditation class and thus beneftted from it to a greater degree.
In raising the level of ego identity, the meditation class was more efective among male students and Buddhists than among female students and students believing in other religions. As mentioned previously, a mechanism by which meditation promotes the development of ego identity is through the activation of the ventromedial prefrontal cortex [31]. Evidence suggests that men exhibited stronger connectivity in the prefrontal cortex regions [30], which may make men more sensitive to the stimulating efect of meditation for the promotion of ego identity. Regarding the greater beneft of meditation for Buddhists, the inclusion of Ganhwa Seon, a traditional Buddhist meditation that strives to fnd the answer to a question of choice, in the class might be a relevant factor. In Korea, meditation, in general, is regarded as a part of Buddhist practice, and the meditation class guided by Buddhist spiritual leaders might have created an unfamiliar environment that hindered non-Buddhists from immersing themselves in meditation practice. Conversely, Buddhist students, out of reverence for Buddhism and Buddhist spiritual leaders, might have engaged in meditation practice more fully and truly rather than approaching meditation functionally or technically, and thus might have reaped the beneft [35]. Our fnding is also aligned with the observation that individuals who grow up in a Buddhist culture have a tendency toward higher levels of ego development [28].
Past studies have shown the benefcial efects of meditation on improving perceived stress, self-efcacy, selfesteem, and spiritual well-being, but in our study, the meditation class did not confer signifcant benefts for these outcomes [36][37][38][39]. Diferences in the type and setting of meditation might have contributed to the inconsistent fndings. Unlike the previous studies [36][37][38][39] that examined the efect of mindful meditation, the most widely practiced meditation and also employed as a part of psychotherapy in clinical settings [40], our study evaluated an integrated form of mindfulness meditation and Ganhwa Seon. Ganhwa Seon might have enriched the medication class by introducing students to a diferent variation of meditation than mindfulness meditation alone. However, with Ganhwa Seon rooted in Buddhism and led by Buddhist spiritual leaders, students could have misinterpreted Ganhwa Seon as a religious intervention rather than a neutral meditation practice, which might have created some disapproval and dislike of the meditation practice, leading to no efcacy. In fact, a study found that college students had diferent preferences for diferent meditation methods [41]; and thus, choosing the right type of meditation for oneself appears critical to reaping the benefts of meditation practice.
Tere are several strengths in our study. Tis is the frst study to investigate the combined efects of the two representative meditations, mindful meditation (the most popular meditation practice in the West) and Ganhwa Seon (the mainstream meditation within Korean Buddhism). By including about 250 participants, it is a large-scale study compared to other previous studies on meditation, which are often limited to less than 100 [3]. Te large study size allowed for analyses to explore characteristics that can help identify individuals who would beneft most from meditation practices.
Our study also has several limitations. First, because students in the meditation class were graded on a pass/fail basis rather than with letter grades, they might not have fully engaged in the meditation practice. Tis might have led to an underestimation of meditation's benefts. Second, the medication course was ofered by diferent instructors, and thus, diferent teaching styles across instructors might have created diferences in the meditation efect even though the course syllabus was identical across classes. However, spiritual leaders completed the same course at the same university to lead the course, and there are unifed guidelines in the textbook for running the course. Furthermore, in our multivariable regression analysis, we adjusted for an instructor. Tus, our efect size measures the efect of meditation, removing variation due to diferences in instructors. Tird, the unique characteristics of our study setting, in which Buddhist spiritual leaders guided meditation incorporating Buddhism and students were forced to engage in meditation as part of a required course rather than opting to practice meditation, might have created emotional resistance from students of other religions, which might have underestimated the beneft of meditation. Last, the meditation in our study was conducted in a class held at a Buddhist university, and only those who answered the questionnaires twice were included in the study. In this regard, the subjects of our study are relatively familiar with meditation, so their interest in meditation may be diferent from that of the general population. Due to this, the efect of meditation we found may be overestimated or underestimated compared to the general population.

Conclusions
A semester meditation course incorporating mindfulness meditation and Ganhwa Seon was associated with improvements in adult ADHD scores and ego identity among college students. Te benefcial efects of meditation courses varied according to several baseline characteristics, which provide evidence for targeted meditation practice. For effective control of mental health issues among college students, future studies are warranted to fnd characteristics that can identify a subgroup of individuals who would beneft most from meditation practice. 6 Evidence-Based Complementary and Alternative Medicine

Data Availability
Te data that support the fndings of this study are available from the corresponding author upon reasonable request.

Disclosure
Yuri Kim and Jaewon Khil are co-frst authors.

Conflicts of Interest
Te authors declare that there are no conficts of interest.