Psychiatry Research 275 (2019) 137–142

Contents lists available at ScienceDirect

Psychiatry Research
journal homepage: www.elsevier.com/locate/psychres

A randomized controlled trial of mindfulness in patients with T

schizophrenia✰
Kun-Hua Lee
Department of Educational Psychology and Counseling, National Tsing Hua University, 521 Nan-Da Road, Hsinchu City 30014, Taiwan

A R T I C LE I N FO A B S T R A C T

Keywords: Cognitive Behavioral Therapy (CBT) is frequently used to attenuate the severity of positive schizophrenia
Mindfulness symptoms; however, few studies have focused on attenuating negative symptoms. Recently, researchers have
Negative symptoms become interested in the effects of mindfulness-based intervention (MBI) on schizophrenia, but the lack of
PANSS evidence-based results from random clinical trials (RCTs) has limited their effectiveness. Moreover, longitudinal
Schizophrenia
data must be examined using appropriate study designs. We recruited 60 schizophrenia patients and randomly
GEE
assigned them to an MBI or to a treatment-as-usual group. Negative symptoms, positive symptoms, mindfulness,
and depression were assessed at baseline, post-course, and at a 3-month follow-up. Descriptive analysis and
generalized estimating equations (GEEs) were used to examine the effects of MBI. We found that MBI mitigated
the severity of negative symptoms and of general schizophrenic psychopathology except for the positive
symptoms and for those of depression. Unexpectedly, we did not find long-term effect of mindfulness on negative
symptoms. Larger sample sizes, long-term practical course, more rigorous study procedures, and a double-blind
design should be considered in future studies.

1. Introduction effect on the severity of positive symptoms in patients with acute

schizophrenia, but that it has only a small-to-moderate effect on the
The lifetime prevalence of schizophrenia has been estimated to be relapse of positive and negative symptoms (Hoffman et al., 2012). Ef-
0.4% (Saha et al., 2005), and for decades schizophrenia has been fective schizophrenia intervention should focus on subjective well-
considered and treated as a severe mental disease. Simeone et al. (2015) being and quality of life, increased functional performance, and pre-
reported that the median prevalence of schizophrenia in 2014 was venting relapses (Dickerson and Lehman, 2011).
0.33%, and that the worldwide lifetime prevalence was 0.49%. The More evidence that supports the beneficial effects of mindfulness-
overall prevalence in China ranged between 0.044% and 0.066% based intervention (MBI) on schizophrenia is accumulating
(Long et al., 2014). The prevalence of schizophrenia has been stable (Khoury et al., 2013). Of five patients with severe schizophrenia who
throughout the past few decades, and because the disease is extremely underwent eight MBI sessions and regular daily meditation for eight
burdensome to schizophrenia patients and their caregivers (Hsiao and months, all reported significant mitigation in the severity of their hal-
Tsai, 2014), efficacious treatments should be a biomedical priority. lucinations and delusions (Sheng et al., 2018). Moreover, a cross-sec-
Better therapies would give patients and their caregivers more con- tional study (Dudley et al., 2018) reported that a higher extent of
fidence about how to maintain a balanced and healthy lifestyle and, mindfulness attenuated distress when patients heard voices, and that
undoubtedly, more motivation to actually do it. self-compassion partially mediated between mindfulness on the severity
Cognitive Behavioral Therapy (CBT) is a strongly recommended of voices and distress. This indicates that mindfulness can be important
management strategy for schizophrenia (Brus et al., 2012). CBT was for reducing the severity of symptoms and for increasing quality of life
originally developed to ameliorate depression and anxiety, and it was and subjective well-being.
assumed that depression and its sequelae were maladaptive beliefs MBI is a kind of psychological and behavioral practice based on
caused by disturbing life events (Roth et al., 2002). To treat schizo- Buddhist meditation, and it focuses on the awareness that emerges
phrenia, CBT was modified to focus on the beliefs about the symptoms through purposely and nonjudgmentally paying attention in the present
and on how to cope with them by guiding the questions (Dickerson and moment to the moment-by-moment unfolding of experience (Kabat-
Lehman, 2011). Evidence confirms that CBT has a strong attenuating Zin, 2003). Practitioners of MBI for schizophrenia claim that its patients

✰
Conflict of Interest: Kun-Hua Lee has no conflicts of interest related to this study.
E-mail addresses: kunhualee@mail.nthu.edu.tw, kunhualee@mx.nthu.edu.tw.

https://doi.org/10.1016/j.psychres.2019.02.079
Received 28 November 2018; Received in revised form 1 February 2019; Accepted 1 February 2019
Available online 19 March 2019
0165-1781/ © 2019 Elsevier B.V. All rights reserved.
K.-H. Lee Psychiatry Research 275 (2019) 137–142

have reported relaxation, relief from psychological symptoms, cognitive

change, and focus on the present (Brown et al., 2010). Schizophrenia
patients developed emotions and beliefs that were more adaptive, and
they said that MBI motivated them to more closely maintain balanced
and healthy lifestyles (Tabak et al., 2015). However, many questions
about the efficacy of MBI and the mechanism of mindfulness on schi-
zophrenia await resolution (Chadwick, 2014).
Although confirmatory evidence of the benefits of MBI for schizo-
phrenia patients is currently being reported by randomized clinical
trials (RCTs), there are limits to its ability to attenuate schizophrenia
symptoms, especially negative symptoms (Cramer et al., 2016). In Hong
Kong, a larger-scale (n = 107) RCT on the effects of MBI on schizo-
phrenia patients showed significantly ameliorated positive and negative
symptoms after six months compared with patients who underwent
only treatment-as-usual (TAU) (Chien and Thompson, 2014).
In the past, the paired t-test and analysis of variance (ANOVA) were
frequently used to evaluate follow-up and longitudinal data. However,
ANOVA and repeated measurements could not precisely present the
changes of an individual to limit the effectiveness of intervention
(Zeger et al., 1988). Generalized Estimating Equations (GEEs) can be
used to analyze normal and non-normal data in RCTs and longitudinal
studies (Bell et al., 2018). In the present study, we not only examined
the effectiveness of mindfulness-based intervention on negative symp-
toms and psychotic symptoms, but also profiled the trend of changes in
outcome measures on schizophrenia. Thus, we used GEEs to analyze our
follow-up data.
In sum, the present study aimed to use randomly assigned and GEE
analyses to examine the effect of MBI on the severity of psychotic
symptoms in schizophrenia patients. We hypothesized that:

(1) At baseline, there would be no significant differences in the seve-

rities of positive symptoms, negative symptoms, general psychotic Fig. 1. CONSORT flowchart.
symptoms, and depression between the MBI and TAU groups. *: The participants who did not complete at least four sessions were treated as
(2) At baseline, there would be no significant differences in the extent the participants who failed to intervention.
of mindfulness between the MBI and TAU groups.
(3) Post-course, the severity of positive and negative symptoms in the The research assistant stated the purpose of this project and ex-
MBI group would be significantly lower than in the TAU group. plained each patient's personal rights and potential risks before they
(4) Post-course, the extent of mindfulness in the MBI group would be signed a written informed consent. Patients were then randomly as-
significantly higher than in the TAU group. signed to the mindfulness group (MBI; n = 30) or to the treatment-as-
(5) At the 3-month follow-up, the severity of positive and negative usual group (TAU; n = 30). Before undergoing MBI, the baseline se-
symptoms in the MBI group would be significantly lower than in the verity of the positive and negative symptoms, and the extent of the
TAU group. mindfulness, were all assessed. The research assistant was responsible
(6) At the 3-month follow-up, the extent of mindfulness in the MBI for the interview and assisted participants on the completion of the self-
group would be significantly higher than in the TAU group. report questionnaires. Two assessors were trained by experienced
clinical psychologists. Before assessing, the principal researcher as-
2. Methods sessed the same participant with the assessors and discussed any in-
consistent scores in order to improve the consensus. The same assess-
2.1. Study design ments were made after eight weeks of MBI and at the three-month
follow-up. The CONSORT flowchart is shown in Fig. 1.
This RCT examined the effects of MBI on schizophrenia patients.
PANSS scores at baseline, post-course, and follow-up between the MBI
and TAU groups have been analyzed using repeated measures 2.3. Interventions
(Hsieh et al., 2018).
2.3.1. Mindfulness-based interventions
2.2. Patients and procedures We developed an eight-session, 1.5-h weekly MBI program for
schizophrenia based on a self-awareness, self-regulation, and self-
We recruited 60 schizophrenia patients from rehabilitation wards transcendence (S-ART) model of mindfulness (Vago and
and daycare centers in mental hospitals in eastern Taiwan. All were Silbersweig, 2012). S-ART assumes that mindfulness practice effica-
referred by psychiatrists, nurses, occupational therapists, clinical psy- ciously regulates the behaviors, increases the awareness, and maintains
chologists, or volunteers. Yuli Hospital's Institutional Review Board a positive relationship between each patient's self and others. In the
approved the study protocol (YLH-IRB-10307). Inclusion criteria were present study, the eight weeks of MBI primarily focused on practicing
(a) being 18–65 years old, (b) being diagnosed on the schizophrenia self-awareness and self-regulation. Three groups were led by six senior
spectrum, (c) being able to read and write Taiwanese Mandarin clinical psychologists who had undergone a 3-day MBI workshop and
Chinese, and (d) having at least an elementary school education. maintained daily mindfulness practice. During the 3-day workshop,
Patients with (a) psychotic symptoms, (b) delirium, or (c) extensive trained therapists were taught the concepts of mindfulness, mindfully
suicidal ideation, or (d) patients who were violent were excluded. eating, mindfully walking, mindful yoga, mindful meditation, and

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mindful self-compassion. After the workshop, they were asked to two reasons (Gupta, 2011). First, ITT ignores noncompliance and
practice mindfulness daily throughout the week. withdrawal. Second, ITT preserved sample size in the present study.
In the first week, patients were introduced to the concept of Our sample was small because it was difficult to recruit patients. De-
mindfulness and asked to meet the expectations of the MBI group. scriptive analyses, t-tests, and χ2 tests were used to determine the dis-
Homework was assigned at the end of each session. The second week, tributions of demographic and outcome variables in the two groups.
we invited the patients to play simple puzzle games to stimulate their Generalized Estimating Equations (GEEs) are frequently recommended
curiosity. We then taught them a 15-min breathing mediation, which for analyzing longitudinal data when the data are not normally dis-
was assigned as daily homework. The third week, we invited the pa- tributed and the variance of the outcome variables are not constant
tients to mindfully write their name after their homework review. The (Ghisletta and Spini, 2004). In the present study, GEEs were used to
fourth week, we taught them to mindfully eat and to allow themselves examine pre-course, post-course, and follow-up data. Significance was
to experience the effect of habitual behaviors after their homework set at p < 0.05.
review. The fifth week, we asked the patients to mindfully read and
write a short paper. In the sixth and seventh weeks, we asked them to 3. Results
mindfully stretch. The eighth week, we taught them self-compassionate
meditation to increase their capacity for self-care and prosocial beha- 3.1. Demographic data
vior. Each week, a 15-min breathing meditation was done before we
gave the patients feedback and their homework assignment. Only 50 of the recruited patients completed the study: 3 dropped
out because of occupational training, 3 contracted influenza A infec-
2.3.2. Treatment-as-Usual tion, 3 dropped out for personal reasons, and 1 had an acute psychotic
All of our participants were recruited from rehabilitation wards and episode before the intervention (see Fig. 1). The mean age of MBI group
daycare centers. Before entering this study, all of the participants with members was 54.43 ± 6.32 years and of TAU group members was
residual symptoms were treated with routinely scheduled rehabilita- 51.15 ± 6.32 years. There were no significant differences in the se-
tions, such as, walking 5000 steps every morning, occupational re- verity of SANS (t = ‒1.649, df = 56, p = 0.105), PANSS (t = ‒0.788,
habilitation twice a week, nutrition counseling, nursing care, health df = 55, p = 0.434), depressive symptoms (t = 0.296, df = 56,
education group, mild doses of antipsychotic drugs, and other routine p = 0.768), or the level of mindfulness (t = 0.566, df = 56, t = 0.574)
mental hospital activities. Thus, the participants in the TAU group were between dropouts and patients who completed the study, except for age
asked to maintain their routine activities. (t = ‒3.313, df = 57, p = 0.002).
At baseline, there were no significant differences between the MBI
2.4. Measurements and TAU groups in sex (χ2 = 1.482, df = 1, p = 0.223) or educational
level (χ2 = 6.663, df = 4, p = 0.155), but TAU group members were
2.4.1. Personal information: included ID, gender, age, and length of formal significantly older than were the MBI group members (t = 2.722,
education df = 57, p = 0.009). There were no significant differences in outcome
2.4.1.1. Chinese version of the mindfulness attention awareness scale measures between the MBI and TAU groups in PANSS (t = ‒0.388,
(MAAS). This scale was developed by Brown and Ryan (2003) to df = 55, p = 0.699), SANS (t = ‒0.947, df = 56, p = 0.347), level of
assess the extent of dispositional mindfulness. It is sensitive to mindfulness (t = ‒1.793, df = 56, p = 0.078), and depressive symp-
improvements in the extent of a patient's mindfulness. toms (t = ‒0.610, df = 56, p = 0.545) (Table 1).
Chang et al. (2011) translated the MAAS into Chinese and reported
that it had good reliability and validity. It assesses fifteen items rated 3.2. GEE data
from 1 (Never) to 6 (Always). Higher scores mean a lower level of
mindfulness. We treated age as a covariant because of the significant difference in
age between the MBI and TAU groups.
2.4.1.2. Beck depression inventory (BDI-II). The scale was developed to
assess the severity of depressive symptoms (Beck et al., 1988). There are 3.2.1. The effects of mindfulness-based intervention on negative symptoms
21 items rated from 0 to 4 that ask about different depression GEE analysis showed a significant main effect of group on SANS
symptoms. Higher scores mean more severe depressive symptoms (β = 0.661, p = 0.011) and a significant main effect of time on SANS at
(Walter et al., 2003). Cronbach's α of the BDI-II after 8 sessions in time 1 (β = 0.986, p = 0.000). The effect of group × time on SANS
this study was 0.90. reached was significant after baseline (β = ‒0.973, p = 0.000) but not
significant after the post-course (β = ‒0.1, p = 0.53).
2.4.1.3. Scale for assessment of negative symptoms (SANS). The scale was The main effects of group (β = 0.996, p = 0.000) and at time 1
developed by Andreasen (1982) to assess the severity of negative (β = 0.508, p = 0.011) were also significant for the changes of the
symptoms. Twenty-three items are rated from 0 (None) to 5 (Severe). negative symptoms subscale for PANSS. The effect of time × group
Higher scores mean more severe negative symptoms. The reliabilities of after baseline was marginally significant (β = ‒0.439, p = 0.049) but
the five subscales were: affective flattening (0.86), alogia (0.89), not significant after the post-course (β = 0.18, p = 0.44) (see Fig. 2).
avolition (0.68), anhedonia (0.74), and attention impairment (0.86)
(Andreasen et al., 2003). 3.2.2. The effect of mindfulness-based intervention on psychotic symptoms
GEE analysis showed a significant main effect of group on the total
2.4.1.4. Chinese Mandarin version of the positive and negative syndrome scores of PANSS (β = 0.24, p = 0.03) and a significant main effect of
scale (CMV-PANSS). The PANSS includes 30 items rated from 1 to 7 time on the total scores of PANSS at time 1 (β = ‒0.223, p = 0.000).
that assess the severity of the positive and negative symptoms and of The effect of group × time on the total scores of PANSS was significant
the general psychopathology of patients with schizophrenia. Higher after baseline (β = ‒0.363, p = 0.00) but not significant after the post-
scores mean more severe symptoms. The CMV-PANSS showed good course (β = ‒0.07, p = 0.52) (see Fig. 3).
reliability (Cronbach's α = 0.928) (Wu et al., 2015). The main effect of group on the changes in the general psycho-
pathology subscale for PANSS was significant after baseline (β = ‒0.48,
2.5. Statistical analysis p = 0.00) but the main effect s of time (β = 0.22, p = 0.049) was
marginally significant. The effect of time × group after baseline was
Intention to treat analysis (ITT) was used in the present study for also significant (β = ‒0.43, p = 0.01).

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Table 1 after the post-course (β = 0.12, p = 0.39; β = 0.22, p = 0.07) (See

Longitudinal outcome measures between TAU and MBI. Fig. 4).
MBI (N = 20) TAU(N = 30) The main effect of group on mindfulness was not significant
Mean S.D Mean S.D (β = 0.01, p = 0.95), but the main effect of time on mindfulness was
significant (β = ‒0.30, p = 0.01). The effect of group × time on
SANS
mindfulness was not a significant after baseline or after the post-course
Baseline 1.95 0.74 1.64 0.48
Post-course 0.95 0.96 1.52 0.81
(β = ‒0.16, p = 0.38; β = 0.25, p = 0.22).
3-month follow up 0.89 0.20 0.94 0.17
PANSS
Baseline 2.41 0.34 2.28 0.64 4. Discussion
Post-course 2.68 0.39 2.98 0.43
3-month follow up 2.86 0.07 2.63 0.09 4.1. Synthesis and interpretation of findings
Mindfulness
Baseline 1.69 0.24 1.54 0.31
Post-course 1.91 0.50 2.16 0.82
We used an RCT design and GEEs to examine the effects of MBIs on
3-month follow up 3.97 1.12 3.98 1.43 the severity of the positive and negative symptoms of schizophrenia, on
Depression its depression, and on the extent of mindfulness in schizophrenia pa-
Baseline 0.46 0.20 0.42 0.26 tients. After eight sessions mindfulness-based interventions, MBI group
Post-course 0.40 0.48 0.47 0.44
patients reported lower levels of SANS than did those in the TAU group,
3-month follow up 0.42 0.48 0.27 0.26
Positive symptoms but at the 3-month follow-up there was no significant difference in
Baseline 2.13 0.41 1.96 0.62 SANS. The negative symptom subscale of PANSS in the MBI group was
Post-course 3.10 0.29 3.12 0.26 significantly lower at the 3-month follow-up than at baseline, but it was
3-month follow up 3.14 0.23 3.10 0.08 not in the TAU group. There was no significant difference in positive
Negative symptoms
Baseline 3.09 0.80 3.13 1.64
symptoms between the groups post-course or at the 3-month follow-up.
Post-course 2.45 0.90 3.06 0.88 The level of general psychopathology of MBI group patients rose more
3-month follow up 2.10 0.63 2.58 0.81 slowly from baseline to the 3-month follow-up than in the TAU group.
General First, we found that, after the interventions, the SANS of the MBI
Baseline 2.35 0.35 2.15 0.60
group patients was better (lower) than that of the Tau group patients.
Post-course 2.79 0.32 3.07 0.40
3-month follow up 2.82 0.31 3.08 0.50 Despite a slight rise during the follow-up, the severity of the MBI
group's negative symptoms continued to be significantly lower. This
SANS: Scale for Assessment Negative Symptoms; PANSS: Chinese Mandarin was consistent with Johnson et al. (2009), a qualitative study in which
version Positive and Negative Syndrome Scale; Positive: the positive subscale of patients used breathing and loving-kindness meditation to reduce the
Chinese Mandarin version Positive and Negative Syndrome Scale; Negative: the severity of negative symptoms. Patients had positive emotions and felt
negative subscale of Chinese Mandarin version Positive and Negative Syndrome closer to family and friends during these two MBIs; they were peaceful
Scale; General: the general psychopathology of Chinese Mandarin version
and more concentrated on the here-and-now when they practiced
Positive and Negative Syndrome Scale; Mindfulness: Chinese version of
breathing meditation. Therefore, the severities of anhedonia and at-
Mindfulness Attention Awareness Scale; Depression: Beck Depression Inventory
Ⅱ; *:p < 0.05; **:p < 0.01.
tention impairment were attenuated.
Second, in addition to SANS, the negative symptom subscale levels
The main effect of group on the changes of the positive symptoms of PANSS significantly decreased over time in the MBI group at post-
subscale for PANSS was not significant (β = ‒0.03, p = 0.76) but the course and during the follow-up. Our findings were consistent with
main effect of time after baseline was significant (β = ‒1.01, p = 0.00). those of Chien and Lee (2013). Moreover, our findings preliminarily
The effect of time × group after baseline was not significant after supported the efficacy of MBIs for improving the negative symptoms of
baseline (β = ‒0.14, p = 0.40) or after the post-course (β = 0.06, schizophrenia. Schizophrenia patients are encouraged to actively be
p = 0.65). (see Fig. 3) aware of and to experience life through mindfully eating and mindfully
stretching. Therefore, they have to refocus on their everyday activities
and reengage with them to be aware of and to share them. The negative
3.2.3. The effects of mindfulness-based intervention on depression and the symptoms of avolition and affective flattening were attenuated after
level of mindfulness these MBIs. Future studies might want to examine the unique effects of
The main effects of group and time on depression were not sig- each MBI on schizophrenia.
nificant at baseline (β = ‒0.15, p = 0.20; β = 0.04, p = 0.76). The ef- Third, we were unable to confirm the effect of mindfulness on the
fect of group × time on depression was significant after baseline and positive symptom scale of PANSS in the present study. Our data were

Fig. 2. Changes of negative symptoms between MBI and TAU.

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Fig. 3. Changes of positive symptoms and general psychopathology between MBI and TAU.

Fig. 4. Changes of depression and mindfulness between MBI and TAU.

inconsistent with those of Chien and Lee (2013). However, few studies kindness meditation for others and for themselves. These practices not
have examined the effects of MBIs on positive symptoms by directly only helped patients learn to calm down, but also taught them to be-
assessing PANSS or by measuring positive symptoms. For example, come aware of and able to regulate their emotions. Theoretically,
Chadwick et al. (2005) used the Clinical Outcomes in Routine Evalua- schizophrenia patients who accept MBIs can regulate the pathways of
tion Outcome Measure (CORE-OM) to assess the changes of positive their brain circuits, especially for amygdala and other emotional-load
symptoms after MBI, and they reported that overall psychotic symp- pathways (Dickerson and Lehman, 2011; Dudley et al., 2018). The
toms were mitigated by breathing meditation. In the present study, the biomarker of mindfulness should be identified in future studies.
effects of group and of time on negative symptoms were significant. The Fifth, we found in our study no significant difference in the extent of
effect of time by group was not significant, possibly because the severity mindfulness between the MBI and TAU groups. Despite our finding of a
of negative symptoms is not stable and gradually improves even marginal effect of time by group, this is inconsistent with Chien and
without interventions. A meta-analysis (Savill et al., 2015) claimed that Thompson (2014). One possible explanation is that the MBI in the
the severity of negative symptoms decreased across all conditions, but present study was short-term. It was also shorter than that of
more longitudinal studies are required to confirm this. Sheng et al. (2018), who claimed that long-term practice to cultivate
Fourth, we found that general levels of the psychopathology of mindfulness is necessary. Further study should increase the times of
schizophrenia had been mitigated after MBI, which is consistent with mindfulness-based course for schizophrenia in order to deeply cultivate
Chien and Thompson (2014). The schizophrenia patients in the present the level of mindfulness.
study were asked to read mindfully and to do breathing and loving- Sixth, we found no significant differences in depression severity

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