Effects of single-point acupuncture (HT7) in the prevention of test anxiety: Results of a RCT
Effects of single-point acupuncture (HT7) in the prevention of test anxiety: Results of a RCT
Johannes Fleckenstein 0 1
Peter KruÈ ger 0
Karl-Peter Ittner 0
0 Editor: Ethan Moitra, Brown University , UNITED STATES
1 Department of TCM/Acupuncture, Institute of Complementary Medicine, University of Bern, Personalhaus 4 Inselspital , Bern , Switzerland , 2 University Hospital Regensburg , Franz-Josef-Strauû-Allee 11, Regensburg, Germany , 3 Department of Sports Medicine, Institute of Sports Sciences, Goethe-University Frankfurt , Frankfurt am Main , Germany
Twenty-five male subjects (age 28 ± 5 years) were allocated to either verum acupuncture
(n = 12) or sham laser acupuncture (n = 13). Cortisol peaked 20 min after the stress test
(2-fold, 18.11 ± 2 nmol/l) and amylase 10 min after (2-fold, 259 ± 49 U/ml) with no difference
between groups. There were no differences between groups regarding either anxiety
questionnaires or physiological parameters. Compared to reference data (3-fold increase in
cortisol), increase in stress hormones and heart rate seemed somewhat reduced.
Acupuncture may be a possible approach for the treatment of anxiety. Due to the lack of a
no control treatment group, we cannot determine the magnitude of possible specific needle
effects at HT7 to promote specific effects in the neuroendocrine system. Finally this study
only examines the efficacy of a single time treatment.
The number of students using neuro enhancement to improve their performance and to
prevent test anxiety is increasing. The acupuncture point Heart 7 (HT7) has been described as
being prominent in reducing states of anxiety.
We conducted a randomized placebo-controlled, two-armed pilot trial to investigate the
efficacy of a single-point acupuncture treatment at bilateral HT7 compared to sham laser
acupuncture on test anxiety. Test anxiety was induced applying the standardised protocol of the
Trier Social Stress Test. Outcome measures included saliva samples analysed for cortisol
and amylase, anxiety questionnaires and heart rate variability.
Data Availability Statement: All relevant data are
within the paper and its Supporting Information
Funding: The authors received no specific funding
for this work.
Competing interests: Dr. Fleckenstein is the
Deputy Head of the Scientific Chapter of the
German Medical Acupuncture Society DAEGfA. He
received honoraria for academic teaching and
counselling. This does not alter our adherence to
PLOS ONE policies on sharing data and materials.
The German Federal Ministry of Education and Research reports that 13% of all first-year
undergraduate students seek counselling services for test anxiety [
]. Test anxiety also seems to
be more prevalent in students who dropped their first study major and started another. In this
group, 17% sought counselling services. It was also shown that the number of students affected
by test anxiety and require help rises with the age of the student [
The experience of anxiety in a test situation has several different components. There is an
affective component, which occurs as an unpleasurable, nervous feeling of affective
excitement, a cognitive component, which includes concern for impending failure and its possible
consequences, a physiological component, for example an increased heart rate, sweating or
nausea, and a motivational component, which involves escape and avoidance tendencies [
In this regard, current investigations distinguish between situationally experienced test
anxiety, or so-called "state test anxiety," and habitual personality-specific test anxiety, which is
referred to as "trait test anxiety" [
The consequence of such anxiety is that the performance of complex and difficult tasks,
which require attention, decreases. The effect on motivation is ambivalent. Test anxiety is
known to reduce interest and motivation but can be beneficial as well since students are more
focused on avoiding errors. In general, however, it has been proven to significantly weaken
one's abilities to solve cognitively challenging tasks [
Middendorf et al [
] showed in their survey that the most popular options for students to
relieve anxiety and stress is meeting with friends (69%) and entertainment (67%). Other
remedies are sleeping (63%), sports activities (58%) or relaxing and wellness (46%).Drinking coffee
is a common strategy for staying awake and maintaining concentration. Diekelmann et al.
investigated whether caffeine has any effect on memory after sleep deprivation. The group
given caffeine had 10% less false memories than those who did not receive caffeine [
number of students using neuro enhancement to improve their performance and to prevent
test anxiety is ever increasing. A US survey estimated that nearly 7% of students in US
universities had used prescription stimulants against anxiety, and that on some campuses up to 25%
of students had used them in the past year [
]. Twelve percent of all students questioned in
2012 had used one or more substances to cope with the requirements of studying since starting
their studies [
]. Five percent of these students reported having taken prescription drugs,
including analgetics, sedatives, psychostimulants or stimulants, and another 5% so-called
Previous studies have shown that acupuncture can be a beneficial, non-pharmacological
alternative for the reduction of test anxiety [
], and the acupuncture point Heart 7 has
always been a central part of the point concepts used in these studies. A variety of animal
studies investigated the effects of HT-7 on anxiety in drug and alcohol withdrawal. Suggested
mechanism to attenuate anxiety-like behaviour include the activation of the dopaminergic
system  and through the mediation of the GABA-A receptor system [
]. Clinical evidence
favouring these effects on anxiety is still limited. An uncontrolled pilot study claimed HT 7 to
cause point-specific effects [
]. A recent RCT showed acupressure of HT7 in combination
with LI4 to be superior to sham and control in relieving anxiety [
A further limitation in these previous studies is the lack of a standardized setting to provoke
anxiety. Kirschbaum et al. addressed this problem by designing a protocol known as the Trier
Social Stress Test, a scientifically validated instrument for the provocation of psychobiological
This study aimed to reproduce the described effects of acupuncture at HT7 on anxiety in a
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We conducted a randomized, controlled, two-armed pilot trial from March to April 2014 to
investigate the efficacy of a single acupuncture treatment at bilateral acupuncture point Heart
7 on experimental acute test anxiety as compared to sham laser acupuncture. The study was
performed according to the guidelines stated in the Declaration of Helsinki (Version Fortaleza
2012), and ethical approval was granted by the Ethics Committee of the University of
Regensburg, Germany. The ClinicalTrials.gov identifier is NCT02142231 (see S1, S2 and S3 Files).
We screened male students of the Medical School (3rd to 5th year) at the University of
Regensburg for eligibility. Written informed consent was obtained from all participants.
Inclusion criteria were smoking cessation for 24 hours, compliance and a history of test anxiety
with a value > 4 cm on a visual analogue scale (VAS, range 0±10 cm). Exclusion criteria were
severe physical or psychological illness, a psychiatric record in the medical history, the
continuous intake of psychiatric medication, tranquilizers or neuro-enhancers, an acupuncture
treatment within the last 4 weeks, current hang-over, drug consumption, or smoking habits with
more than 5 cigarettes per day.
An independent person prepared 25 sealed, opaque envelopes on the basis of a
randomization sequence generated by a computer-based algorithm (Research Randomizer, Version 4.0)
in order to allocate 12 participants into each group. Participants were allocated by means of
the ascending numbered envelopes to one of the two trial arms receiving either single needle
acupuncture at point Heart 7 (ACU) or laser acupuncture (LAS).
Participants laid comfortably on a bed while acupuncture needles (Seirin1 0.15 mm
diameter and 15 mm length) were placed bilaterally into the acupuncture point Heart 7 (ACU) until
the sensation of deqi was achieved. No additional manipulation was sought. Needle-in time
was 20 minutes. The practitioner had achieved the A-level Grade of the German Medical
Sham laser acupuncture was performed at the same acupuncture point, bilaterally, without
palpating or touching the skin (laser pen manufactured by 3B Scientific,GmbH, Hamburg,
Germany). Treatment was one minute per point with an additional 18 minutes of resting time.
Both patient and therapist were blinded to the fact that a sham laser was used instead of a
verum laser, as published previously.[
The experimental sessions were conducted between 13:00 and 18:00 o'clock. Participants
were told to refrain from eating and drinking anything but water for 2 h, and from intense
physical activity, caffeine, nicotine, and alcohol for 24 h before the experiment. The ECG
recording equipment (Polar) was attached first and then the recording was started.
To induce test anxiety, the Trier Social Stress Test (TSST) was used, combining a 10 min
preparation phase followed by a 5 min mock job interview, and a 5 min mental arithmetic exercise
]. Both tasks were performed 2 m in front of two evaluative panel members (not part of the
study team), dressed in white laboratory coats, and a conspicuous video camera and microphone.
The socio-evaluative character of this performance task was further underscored by presenting
the panel members (a retired male finance manager and a female psychologist) as experts in
evaluation of nonverbal behaviour. The TSST reliably activates both the HPA-axis and the sympathetic
nervous system. During recovery, subjects remained seated in a quiet room for 60 min.
The main outcome was the assessment of cortisol in the saliva (8 different assessment
times). All saliva probes were sampled by means of the standardized Salivetten1 Cups,
(Sarstedt, NuÈrmbrecht, Germany). Participants chew for 30 seconds on an absorptive tissue and
subsequently place saliva in the cup. The cups are then closed and stored at -20ÊC until further
analysis. All laboratory analyses were performed by DRESDEN LAB SERVICE GmbH,
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Secondary outcomes included the assessment of amylase in the saliva. The following
questionnaires were used to assess different dimensions of stress and anxiety: the Multidimensional
Mood Questionnaire MDBF [
], the Primary Appraisal Secondary Appraisal scale PASA
], the State-Trait Anxiety Inventory STAI [
], and perceived stress on a 10 cm visual
analogue scale (VAS; with 0 = no stress and 10 = worst imaginary stress). Times of assessment
adhered to the TSST protocol as published previously [
A Polar RS800 device (Polar Electro GmbH Germany, D- 64572 BuÈttelborn) was used to
constantly record a high resolution ECG during the experiment. We extracted the heart rate
(HR) and the heart rate variability (HRV) from the raw data.
Expectations about the outcome are the main modifying variables of the placebo effect.
Participants were therefore asked to evaluate whether their satisfaction and expectations were met
by means of a questionnaire as suggested by Vincent and Lewith [
]. This questionnaire is
comprised of 4 items that are evaluated on a 10 cm VAS: (1) Alleviation, (2) Recommendation,
(3) Logic, and 4 Other.
A power analysis was performed using G Power (University of DuÈsseldorf, Germany)
estimating a small to medium effect size (d = 0.29, α-error = 0.05, power = 0.95)) and a
time-dependent progression, according to a suggested total sample size of 24 subjects (i.e. 12 per group).
All data was distributed in a way that is consistent with normality, and are thus expressed as
mean ± standard deviation.
To analyse longitudinal data (more than 2 time points; changes to baseline), we applied a
mixed-effects analysis, i.e. a time x group model (ANOVA for repeated measures). The model
was applied to analyse the effects on cortisol, amylase, heart rate and heart rate variability.
Data was analysed according to Mauchly's test for sphericity and the Greenhouse-Geisser
correction was used in case sphericity was not present. Weight and trait anxiety at baseline were
included as covariates. If statistically significant, the respective outcome variable was followed
by post-hoc pairwise comparisons (unpaired t-test) of change scores between each of the time
points and baseline.
All other data was analysed applying unpaired Student's t-tests for inter-group, or paired
ttests for intra-group analysis.
Twenty-five male volunteers (mean age 27.9 (SD 4.6) years, height 182.0 (6.5) cm, weight 79.7
(10.1) kg) participated in this study, with no drop-outs (Fig 1). Global test anxiety was reported
with 7.4 (1.3) cm VAS (range 6.0±10.0) at baseline. Volunteers were randomized into two
groups with 12 subjects allocated to needle acupuncture and 13 subjects to sham laser
acupuncture. Groups differed in weight and in regard to their state of anxiety (STAI-T, see
Table 1). As both variables are known to influence each other [
], they were used as covariates
in the analysis of the main effects.
The perceived stressfulness of the TSST was rated as 5.3 (1.6) cm VAS (range 3.0±8.0) and
the comparability to a medical state exam was valued as 4.0 (2.1) cm VAS (range 1.0±8.0) with
no differences observed between groups.
Stress hormones in the sputum at baseline were cortisol = 9.4 (5.9) nmol/l and
amylase = 121.6 (104.6) U/ml. The largest magnitude of cortisol was Δ8.7 (11.8) nmol/l at T4 (20
minutes after the stress test; p = 0.001) and of Δ137.4 (161.6) U/ml at T3 (10 minutes after the
stress test; p < 0.001).
Time x group analysis of changes to baseline revealed no significant differences in the
increase of cortisol (7x2; F(2;12) = 0.5 p = 0.811) or amylase (5x2; F(3;8) = 1.2 p = 0.325)
between groups (see Fig 2A and 2B).
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Assessed for eligibility (n= 25)
Excluded (n= 0)
Randomized (n= 25)
Allocated to Acupuncture (n= 12)
♦ Received allocated intervention (n= 12)
Allocated to Sham (n= 13)
♦ Received allocated intervention (n= 13)
Lost to follow-up (give reasons) (n= 0)
Lost to follow-up (give reasons) (n= 0)
Analysed (n= 12)
Analysed (n= 13)
Fig 1. Consort study flow chart.
Time x group analysis of changes to baseline revealed no significant differences between
groups with respect to other psychological outcomes as follows: MDBF (3x2; F(2;4) = 1.4
p = 0.257; Fig 2E), and STAI-S (2x2; F(2;2) = 0.08 p = 0.927; Fig 2F). Changes in PASA did not
differ between groups (unpaired t-test p = 0.524 (95%-CI -2.8;5.3))
Time x group analysis of changes to baseline revealed no significant differences with respect
to the perceived stress (on a VAS scale) during the experiment (4x2; F(2;6) = 0.4 p = 0.832).
The heart rate (at baseline 76.7 [15.2] min-1) significantly decreased after
intervention/resting to 66.9 (12.7) min-1 (p < 0.001), and peaked during the TSST at 89.5 (18.2) min-1 (p <
0.001). The heart rate variability (at baseline was 795.7 [233.3] ms) significantly increased after
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intervention/resting to 936.6 (174.4) ms (p < 0.001), and was shortened during the TSST
(706.6 [152.8] ms, p < 0.001).
Time x group (5x2) analysis of changes to baseline revealed no significant differences
between groups with respect to heart rate (F(2;8) = 0.6 p = 0.630) or heart rate variability
((F(2;8) = 0.9 p = 0.499; Fig 2C and 2D).
We performed a credibility assessment according to Vincent, and observed no differences
with respect to the four variables at baseline, or at the end of the study (Table 2).
This study demonstrated that treatment at the acupuncture point Heart 7 did not show any
treatment-specific effects on the physiological response in a setting of standardized anxiety
when compared to a sham control. However, when compared to reference scores [
increase in the peptides cortisol and amylase was 2-fold, which is less than expected (3 up to
4-fold). This may be due either to indirect effects (so called treatment-dependent unspecific
]), or to individual differences between the study populations. The TSST paradigm
has been studied in depth and is a validated test protocol to provoke anxiety [
]. Still it may
not be equivalent to an acute stress response in real life. Our data suggest that care and
attention given during a real or sham acupuncture treatment could already reduce the physiological
and psychological stress response to some extent.
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Fig 2. Describes the physiological and psychological effects of acupuncture on test anxiety, i.e. the time-course of (A) saliva cortisol and (B) saliva amylase. (C) and (D)
depict the ECG analysis with respect to heart rate and heart rate variability. (D) is the score of the MDMF and (F) the scores of the STAI-state anxiety. The red flashes
labelled TSST indicate the occurrence of the stress test, the acupuncture needle depicts the time of intervention (30 minutes prior to the TSST). The times are as follows:
-40 and -10 minutes previous to the TSST, and +10, +20, +30, +40, +55, +70 minutes thereafter (as suggested by Kirschbaum et al., 1993).
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We believe that the methodology of this study adheres to the latest recommendations
defined in the literature. We specifically avoided using a sham needle control due to the
probable mixture of physiological stimuli when touching the skin [
]. Sham laser acupuncture is
thought to be an accurate control for acupuncture since all psychological dimensions are
addressed and physiological stimuli e.g. touching the skin can be avoided [
]. We also
carefully adhered to the STRICTA and CONSORT criteria for conducting and reporting
acupuncture trials (S1 and S2 Files; [
]). Furthermore, we only included male subjects, first due to the
complex nature of the female endocrinology, and second because male subjects seem to be
more vulnerable to psychosocial stress [
]. This improves on the one hand the homogeneity
of the study, but on the other reduces its generalizability. Finally, we thoroughly followed the
instructions described in the TSST handbook, as suggested by Kirschbaum et al. (1993), in
order to ensure that our data is reliably comparable to other current or ongoing studies.
To our knowledge, there is no acupuncture study that has been performed using the TSST
paradigm. Other studies in this field show that e.g. taiji [
], cognitive therapy [
psychotherapy all successfully reduced the stress response. The increase in saliva cortisol seen in
our study is no different than that obtained by the best treatment responders within these
studies when compared to healthy controls. Thus, this strengthens the hypothesis that
psychological factors are very powerful in reducing acute stress.
The hypothesis that acupuncture could be used to reduce stress is linked to the clinical
observation that acupuncture treatments cause major relaxation in patients. This effect has
been attributed to modulations in the autonomic nervous system [
]. In addition,
acupuncture is also assumed to enhance parasympathetic stimulation [
Unfortunately, there are only a few studies investigating the impact of acupuncture on
(test) anxiety. A recent study evaluating the effects of auricular acupuncture on the
psychological dimensions of real exam anxiety in medical students barely shows any differences between
verum and placebo treatment [
]. Auricular acupuncture for 4 weeks significantly decreased
tension, anxiety, anger, and aggression in psychiatric patients, as assessed by the visual
analogue scales [
]. An integrative review from 2016 found 19 articles with 11 of them generally
supporting the use of acupuncture to reduce anxiety [
]. Nonetheless, this review article still
has some risk of bias. Studies investigating the effects of acupuncture on both anxiety and
cortisol are rare. One clinical study exists that showed that acupuncture does not significantly
reduce anxiety and serum cortisol in women undergoing embryo transfer when compared to
]. In female dysphonic speakers, acupuncture did not reduce salivary cortisol or
emotional stress when compared to sham [
]. A further study investigating the effects of
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acupuncture or attention in people suffering chronic stress observed a trend towards
significance in improving the diurnal profile of salivary cortisol for both groups [
]. In athletes,
acupuncture significantly increased salivary immunoglobulin A and reduce salivary cortisol prior
to competition [
]. Acupuncture significantly reduced the extent of orthostatic stress
correlates with the change in morning salivary cortisol [
]. Finally, acupuncture has been shown to
decrease the serum cortisol concentration of horses subjected to startle tests, which are
stressful conditions for the animals [
It is important to state that the above-mentioned studies did not all apply acupuncture at
Heart 7, but included other points or systems as well (e.g. auricular acupuncture). In this
study, we chose Heart 7 due to both its historic and scientific importance. Heart 7 (神門,
pinyin: shen men, translation: spirit gate) is considered to calm both mood and spirit.
Experimental research in rats suggests that this point inhibits cocaine-induced locomotor activity, and
that its action is mediated by A-fibre activation of the ulnar nerve [
]. There is also evidence
that stimulation of the specific acupoint Heart 7 (and not others) helps to normalize the release
of dopamine in the mesolimbic system following ethanol withdrawal [
], thereby exerting
anxiolytic effects [
]. Acupuncture at HT7 was shown to reduce anxiety-related behaviours
and modulate the hypothalamic-pituitary-adrenal system in a maternal separation model [
Although we are aware that these are only small observations drawing a fragmentary sketch as
to how acupuncture may contribute to the psychoneuroendocrine system, but considered
together they provide some evidence that acupuncture at Heart 7 may reduce not only
endocrine parameters of stress, but also perceived anxiety.
The major limitation of this study is the lack of a no treatment control, which would have
been helpful to evaluate and rate the clinical impact of the obtained results. In addition, the
sample size estimation is hypothetical as there is no clinical cut-off in increase indicating
cortisol levels to represent less stress. Even as our data is comparable to reference data published by
other groups, we are aware about the possible chance of bias when interpreting the results. The
small sample size may also have caused a loss of effect in outcomes close to significance. This
research is of a preliminary and hypothesis-generating nature.
Acupuncture may be a possible approach for the treatment of anxiety. The data of our study
suggest that treatment-related unspecific effects (e.g. attention) are part of this observation.
Due to the lack of a no control treatment group, we cannot determine the magnitude of
possible specific needle effects, showing the treatment at the traditional acupuncture point Heart 7
to promote specific effects in the neuroendocrine system. Finally this study only examines the
efficacy of a single time treatment, future studies are necessary to show whether the specific
effects of verum acupuncture are more sustainable in the long run and whether they may be of
S1 File. Consort 2010 checklist. Checklist according to the CONSORT criteria.
S2 File. Stricta_checklist_in_word_-_14th_june_2013. Checklist adding reporting in
acupuncture studies as suggestedby the STRICTA criteria.
S3 File. AcuTA_Trial Protocol_1.0. Study protocol as approved by the Ethics Committee.
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Parts of this manuscript constitute the medical doctoral degree of Peter KruÈger. We thank
Christine Cavanna, Trial associate at the UniversitaÈtsklinikum Regensburg, Germany, for
proofreading and editing the manuscript.
Conceptualization: Johannes Fleckenstein, Peter KruÈger, Karl-Peter Ittner.
Data curation: Johannes Fleckenstein, Peter KruÈger.
Formal analysis: Johannes Fleckenstein, Peter KruÈger, Karl-Peter Ittner.
Investigation: Johannes Fleckenstein, Peter KruÈger, Karl-Peter Ittner.
Methodology: Johannes Fleckenstein, Peter KruÈger, Karl-Peter Ittner.
Project administration: Johannes Fleckenstein, Karl-Peter Ittner.
Resources: Johannes Fleckenstein, Karl-Peter Ittner.
Software: Johannes Fleckenstein.
Supervision: Johannes Fleckenstein, Karl-Peter Ittner.
Validation: Johannes Fleckenstein.
Writing ± original draft: Peter KruÈger, Karl-Peter Ittner.
Writing ± review & editing: Johannes Fleckenstein, Peter KruÈger, Karl-Peter Ittner.
10 / 12
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