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Intl. Journal of Clinical and Experimental Hypnosis, 62(1): 1–28, 2014Copyright © International Journal of Clinical and Experimental HypnosisISSN: 0020-7144 print / 1744-5183 onlineDOI: 10.1080/00207144.2013.841471
A META-ANALYSIS OF HYPNOSIS FORCHRONIC PAIN PROBLEMS:
A Comparison Between Hypnosis, Standard Care,and Other Psychological Interventions
Tomonori Adachi, Haruo Fujino, Aya Nakae, Takashi Mashimo,and Jun Sasaki1
Osaka University, Japan
Abstract: Hypnosis is regarded as an effective treatment forpsychological and physical ailments. However, its efficacy as a strategyfor managing chronic pain has not been assessed through meta-ana-lytical methods. The objective of the current study was to conduct ameta-analysis to assess the efficacy of hypnosis for managing chronicpain. When compared with standard care, hypnosis provided mod-erate treatment benefit. Hypnosis also showed a moderate superioreffect as compared to other psychological interventions for a non-headache group. The results suggest that hypnosis is efficacious formanaging chronic pain. Given that large heterogeneity among theincluded studies was identified, the nature of hypnosis treatment isfurther discussed.
Many people are suffering from chronic pain worldwide (Verhaak,Kerssens, Dekker, Sorbi, & Bensing, 1998). Chronic pain not only per-sonally impacts those individuals but is also associated with greateconomic cost (i.e., health care costs) inflicted by such conditions (Turk,2002). The United States Congress passed into law a provision declar-ing the 10-year period beginning in January 1, 2001, as the Decadeof Pain Control and Research (Lippe, 2000). This legislation reflectsthe considerable societal drain that can be associated with chronicpain. While chronic pain results in severe external consequences forthe self and society, psychological factors can exacerbate the experi-ence of chronic pain (e.g., catastrophizing, depression, and fear; Cook,Brawer, & Vowles, 2006; Jensen, Turner, & Romano, 2001; Spinhovenet al., 2004; Sullivan et al., 2001, Vlaeyen, Kole-Snijders, Boeren, & vanEek, 1995). Psychotherapy is widely used to help alleviate chronic pain.
Manuscript submitted August 23, 2012; final revision accepted November 20, 2012.1Address correspondence to Tomonori Adachi, Shinri-Kyouiku Soudansitsu,
Graduate School of Human Sciences, Osaka University, 1-2 Yamadaoka, Suita, Osaka,565-0871, Japan. E-mail: [email protected]
1
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2 TOMONORI ADACHI ET AL.
Cognitive-behavioral and hypnotic approaches are two strategies thatappear to be rather popular and effective (Kisley, Campbell, Skerritt, &Yelland, 2010).
Hypnosis has long been shown to be an effective psychological treat-ment (Melzack & Wall, 1982). Several brain-imaging studies assessinghypnotic analgesia have received a fair amount of research atten-tion (Abrahamsen et al., 2010; Faymonville et al., 2000; Hofbauer,Rainville, Duncan, & Bushnell, 2001; Jensen, 2010; Rainville, Duncan,Price, Carrier, & Bushnell, 1997).
Although some individual studies have shown the efficacy of hyp-nosis for intractable chronic pain (Haanen et al., 1991; Jensen Barber,Romano, Hanley, et al., 2009; Jensen Barber, Romano, Molton, et al.,2009; Muraoka, Komiyama, Hosoi, Mine, & Kubo, 1996), the fieldwould benefit from efforts to summarize results of individual inter-ventions to determine the overall efficacy of hypnotic treatment. Onlya handful of studies have reported the overall efficacy of hypnosisfor chronic pain (Jensen & Patterson, 2006; Montgomery, Duhamel, &Redd, 2000; Patterson & Jensen, 2003). While Jensen and Patterson, andPatterson and Jensen, provide a narrative review of the literature, onlyMontgomery et al. have provided a systematic review. Montgomeryand colleagues’ review is of great utility, because it summarizes theresults of individual interventions for clinical and experimental painusing a meta-analysis.
Montgomery et al. (2000) investigated the effects of hypnosis forclinical pain including burns, coronary disease, cancer, headache, andexperimental pain inductions (i.e., cold pressor, ischemic pain, andfocal pressure). Statistical analysis was conducted on 18 publishedstudies including samples totaling 933 participants. Calculated effectsizes revealed that hypnosis had a large effect (d = 0.80) in manag-ing clinical pain and a moderate-to-large effect (d = 0.70) for managingexperimental pain.
However, Montgomery et al. (2000) included acute and experimen-tal pain within a broader scope. A meta-analytical study reporting theefficacy of hypnosis that narrows the focus to only chronic pain has notbeen previously conducted. Thus, we conducted a systematic review toinvestigate the efficacy of hypnosis for managing chronic pain.
Method
Search StrategyWe searched three electronic databases: Cochrane Central Register
of Controlled Trials (CENTRAL), MEDLINE, and PsycINFO for studiespublished on or before June 29, 2011. Searches were carried out using acombination of the following keywords: pain, hypnosis, and clinical trial.
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HYPNOSIS FOR CHRONIC PAIN META-ANALYSIS 3
The search strategy for the MEDLINE database is listed in section 1 ofthe Appendix. This approach yielded 130 articles.
For CENTRAL and PsycINFO, we basically used the Medical SubjectHeading and subject search strategies. We also used a keyword searchto complement the former strategies. Hypnosis and pain were used asthe search terms (see the Appendix, sections 2 and 3). This approachyielded 228 articles from CENTRAL and 167 articles from PsycINFO.Moreover, the reference lists of previous review articles (Jensen &Patterson, 2006; Montgomery et al., 2000; Patterson & Jensen, 2003) werescanned to obtain three additional studies.
Inclusion and Exclusion CriteriaOur inclusion criteria were as follows: (a) randomized controlled tri-
als (RCTs) or controlled clinical trials as experimental design; (b) trialstargeting only chronic pain problems; (c) application of hypnosis as themain therapeutic intervention; (d) inclusion of a control group (groupsreceiving both a standard care and other psychological interventions);(e) pain or pain intensity as the main outcome; (f) studies written inEnglish; (g) published journal articles; and (h) studies containing datawhere effect sizes could be calculated, such as means and standarddeviations.
Exclusion criteria were as follows: (a) application of hypnotic-likeinterventions, such as autogenic training (AT) or progressive mus-cle relaxation (PMR) as the main interventions; (b) absence of datathat could be used for calculating effect sizes; (c) studies written in alanguage other than English; (d) use of a case report and/or a narra-tive review as the study method; and (e) unpublished work, doctoraldissertations, published abstracts, books, letters, commentaries, andeditorials.
Assessment of Methodological QualityMethodological quality was assessed with a scale for assessing qual-
ity of psychological trials for treating pain developed by Yates, Morley,Eccleston, and Williams (2005). This scale provides an overall total score(0 to 35) that consists of two subscales. These include a treatment quality(0 to 9) and a design and methods scale (0 to 26). The first and secondauthors (TA and HF) scored all of the studies. TA and HF discussedtheir disagreements in ratings regarding the coding notes of this scale.Each disagreement was discussed until consensus was reached.
Data AnalysisHedges’s g (Hedges & Olkin, 1984) and 95% confidence intervals
were calculated. Q statistics and I2 tests were used to measure statisti-cal heterogeneity; a Q statistic p value of greater than .1 and an I2 value
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4 TOMONORI ADACHI ET AL.
of less than 30% indicated homogeneity (Higgins & Green, 2011). Weused random effects models in all analyses. We examined the effects ofinterventions based on the points of evaluation (i.e., postinterventionor at follow-up) and the type of control groups (standard care or otherpsychological interventions). Calculations were performed using MIX2.0 computer software, and analyses were conducted using SPSS 17.0.
Results
Characteristics of Included StudiesLiterature search. Excluding 53 duplicate articles across three
databases, and two duplicates within the CENTRAL database, 473 rel-evant articles were identified in our initial search. The first author (TA)reviewed these articles and rejected 391 articles on titles and abstracts.TA reviewed full texts of the remaining 82 articles and evaluated themin detail. Finally, only 12 clinical studies met our inclusion criteria.Of these, six were relevant RCTs and six were relevant clinical trials.
Study quality. For the 12 included studies, the mean overall qualityof the studies was 15.00 (SD = 3.13, range: 11 to 21). The mean designquality was 11.00 (SD = 2.30, range: 6 to 15), and the mean treatmentquality was 4.00 (SD = 1.65, range: 2 to 7). When rating design qual-ity, items on an allocation bias and a power calculation were scorelesswithin all included studies.
A Spearman’s rank correlation was calculated to investigate theassociation between the year of publication and treatment qualityscore, design quality score, and total quality score (Eccleston, Palermo,Williams, Lewandowski, & Morley, 2009; Eccleston, Williams, & Morley,2009). This was also calculated between the N at the end of treatmentand three treatment quality parameters. Treatment quality, design qual-ity, and total quality were not associated with the year of publication(treatment, r =.09, ns; design, r =.42, ns; total, r = .33, ns). The N at theend of treatment also was not associated with the three methodologicalqualities (treatment, r = -.09, ns; design, r =-.05, ns; total, r = .05, ns).
Participants. The total number of participants within each studyranged from 22 to 157 (M = 55.75, SD = 37.78). Types of chronicpain included fibromyalgia, headache (i.e., tension-type headache andmigraine), irritable bowel syndrome, multiple sclerosis, noncardiacchest pain, orofacial pain, osteoarthritis pain, spinal cord injury,temporomandibular disorders, and other forms of chronic pain). Onlyfour studies reported participants’ mean pain duration; among these,mean pain duration ranged from 9.5 years to 13.7 years (M = 11.53,SD = 1.76). The mean ages of the study participants were reported in
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HYPNOSIS FOR CHRONIC PAIN META-ANALYSIS 5
8 of 12 studies. Ages ranged from 36 to 64.7 years (M = 47.15, SD =10.24). The percentage of men in the samples across the studies includedin the review ranged from 0% to 76%. The ratio of females exceededmales within 9 studies. A diagnosis of specific illness, degree of pain,degree of a cognitive impairment, and the presence of a mental disor-der was given as inclusion or exclusion criteria. Characteristics of studyparticipants are summarized in Table 1.
Interventions. The main intervention was hypnosis, because ourmajor interest was to clarify the efficacy of hypnotic treatment. Thenumber of interventions varied from 3 to 12 sessions; the duration ofa single session lasted between 30 to 90 minutes. Eleven studies usedindividual treatment formats, and only one study used a group treat-ment format. Only one study just compared hypnosis with a wait-listcontrol, and eight studies compared hypnosis with other psycholog-ical interventions. Three other studies compared hypnosis with bothtypes of control groups. Standard care included no treatment, treat-ment as usual, and a wait-list control. Other psychological interventionsincluded autogenic training, biofeedback, cognitive-behavior therapy(CBT), guided imagery, progressive muscle relaxation, and supportivepsychotherapy (see Table 2).
Measures. Although pain or pain intensity was the main outcome forinclusion criteria, all included studies measured pain or pain intensityusing a variety of scales. Most studies used the numerical rating scale(NRS) or the visual analogue scale (VAS) to quantify pain. Eight stud-ies calculated pain scores to tally the NRS or used 5- to 11-point Likertscales. Most studies used a questionnaire that assessed psychologicalsymptoms (e.g., the Self-Rating Depression Scale, Zung, 1965; the State-Trait Anxiety Inventory, Spielberger, Gorsuch, & Lushene, 1970; the90-item version of Symptom Check List, Derogatis, Lipman, & Covi,1973). Eight studies measured hypnotizability using several differentscales, and four studies measured treatment expectancy. Other outcomeindicators included pain interference, pain coping strategy, quality oflife, sleep quality, perceived control over pain, and capacity for mentalimagery (see Table 2).
Efficacy of the InterventionsA comparison between hypnosis and a standard care. Table 3
displays results for the postintervention comparisons between hyp-nosis and standard care. We pooled the four studies providingpostintervention data allowing us to conduct this comparison. Theeffect size revealed that hypnosis had a significant and moderate effect,g = .60, 95% CI: 0.03–1.17, p < .05, on treatment efficacy compared tostandard care. However, heterogeneity was quite large, Q = 7.03, p <
.10; I2 = 57.30%.
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Tabl
e1
Cha
ract
eris
tics
ofSt
udy
Par
tici
pant
s
Stud
yD
iagn
osis
Pain
dur
atio
n(y
ears
)N
Nat
the
end
oftr
eatm
ent
Mea
nag
e(R
ange
)G
end
er%
(M:F
)
Abr
aham
sen
etal
.(2
009)
Tem
poro
man
dib
ular
Dis
ord
ers
11.9
4340
−0
:100
Abr
aham
sen
etal
.(2
008)
Pers
iste
ntId
iopa
thic
Oro
faci
alPa
in9.
541
4156
(–)
15:8
5
Cas
tele
tal.
(200
9)Fi
brom
yalg
ia11
4739
44.2
(–)
5:9
5G
ayet
al.(
2002
)O
steo
arth
riti
sPa
in13
.71
4136
64.7
(–)
8:9
2Je
nsen
,Bar
ber,
Rom
ano,
Han
ley,
etal
.(20
09)
Chr
onic
Pain
inPe
rson
sW
ith
Spin
al-C
ord
Inju
ry−
3728
49.5
(19-
70)
76:2
4
Jens
en,B
arbe
r,R
oman
o,M
olto
n,et
al.(
2009
)
Mul
tipl
eSc
lero
sis
and
Chr
onic
Pain
−22
2251
.7(2
7–75
)27
:73
Jone
set
al.(
2006
)N
onca
rdia
cC
hest
Pain
−28
26−
−Pa
lsso
net
al.(
2002
)Ir
rita
ble
Bow
elSy
ndro
me
−30
2439
.1(–
)38
:62
Spin
hove
net
al.(
1992
)Te
nsio
nH
ead
ache
−56
4636
(20–
62)
39:6
1te
rK
uile
etal
.(19
94)
Chr
onic
Hea
dac
hes
−15
714
6−
−va
nD
yck
etal
.(19
91)
Tens
ion
Hea
dac
he−
7155
36(1
8-60
)49
:51
Zit
man
etal
.(19
92)
Tens
ion
Hea
dac
hes
−96
79−
46:5
4
6
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Tabl
e2
Cha
ract
eris
tics
ofIn
clud
edSt
udie
s
Stud
yR
CT
Inte
rven
tion
s
Sett
ings
ofH
ypno
tic
Inte
rven
tion
Ass
essm
ent
Poin
tM
easu
res
Pain
Ind
icat
ors
Res
ults
Abr
aham
sen
etal
.(2
009)
Yes
Hyp
nosi
sR
elax
atio
nan
dvi
sual
izat
ion
ofa
com
fort
able
,saf
epl
ace
60m
in.×
4se
ssio
ns;N
od
escr
ipti
ons
abou
tfre
quen
cy;
Ind
ivid
ual;
HW
=lis
teni
ngto
ata
ped
inst
ruct
ion
Pre,
Wee
k3
(Pos
t)N
RS,
MPQ
,CSQ
,SC
L–6
0,PS
QI,
HG
SHS–
A
Pain
dia
ry(t
heav
erag
ed
aily
NR
Spa
insc
ores
ofth
e6
day
sin
each
ofth
efo
urti
me
peri
ods)
∗
Hyp
nosi
s<
Rel
axat
ion
[Pos
t]
Abr
aham
sen
etal
.(2
008)
Yes
Hyp
nosi
sR
elax
atio
nan
dvi
sual
izin
ga
nice
safe
plac
e
5.1
±0.
8(r
ange
3–6)
sess
ions
ofhy
pnos
is;5
.3±
0.9
sess
ions
(ran
ge3–
6)of
cont
rol;
5se
ssio
nsw
ere
plan
ned
;No
des
crip
tion
sab
outf
requ
ency
;H
W=
liste
ning
toa
tape
din
stru
ctio
n;In
div
idua
l
Pre,
Wee
k4
(Pos
t)V
AS
(Pai
nd
iary
),M
PQ,P
SQI,
SCL
–60,
SF–3
6,C
SQ,S
HC
S
MPQ
–Tot
alN
osi
gnifi
cant
dif
fere
nces
betw
een
trea
tmen
tgro
ups
[Pos
t]
(Con
tinu
ed)
7
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Tabl
e2
(Con
tinu
ed)
Stud
yR
CT
Inte
rven
tion
s
Sett
ings
ofH
ypno
tic
Inte
rven
tion
Ass
essm
ent
Poin
tM
easu
res
Pain
Ind
icat
ors
Res
ults
Cas
tele
tal.
(200
9)Ye
sH
ypno
sis
+C
ogni
tive
Beh
avio
rT
hera
pyC
ogni
tive
Beh
avio
rT
hera
pyTr
eatm
ent
As
Usu
al
90m
in.×
12se
ssio
ns;N
od
escr
ipti
ons
abou
tfre
quen
cy;
HW
=lis
teni
nga
tape
din
stru
ctio
n;G
roup
Pre,
Aft
er12
ses-
sion
s(P
ost)
NR
S,FI
Q,M
PQ,
HG
SHS–
AU
sual
pain
inte
nsit
y,co
mpo
site
(NR
S)∗
No
sign
ifica
ntd
iffe
renc
esbe
twee
ntr
eatm
entg
roup
s[P
ost]
Gay
etal
.(2
002)
Yes
Hyp
nosi
sJa
cobs
on’s
Prog
ress
ive
Mus
cle
Rel
axat
ion
No
trea
tmen
t
30m
in.×
8se
ssio
ns;
Wee
kly;
No
des
crip
tion
sab
outH
W;
Ind
ivid
ual
Pre,
wee
k4,
wee
k8
(Pos
t),
3m
onth
(Fol
low
-up
),6
mon
th(F
ollo
w-
up)
VA
S,ST
AI,
SDS,
Imag
ery
vivi
dne
ss(d
eriv
edfr
omSh
eeha
n’s
Que
stio
nnai
reof
Men
tal
Imag
ery,
0-4
poin
ts),
SHSS
–C,
apr
iori
belie
fin
the
trea
tmen
tef
ficac
y(3
-poi
nts
scal
e)
Pain
(VA
S)H
ypno
sis
>N
otr
eatm
ent[
Post
]PM
R>
No
trea
tmen
t[Po
st]
Hyp
nosi
s>
No
trea
tmen
t[3
mon
thFU
]
8
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Jens
en,
Bar
ber,
Rom
ano,
Han
ley,
etal
.(2
009)
Yes
Hyp
nosi
sB
iofe
edba
ck10
sess
ions
;Var
iant
freq
uenc
y;H
W=
liste
ning
toa
tape
din
stru
ctio
nat
leas
tonc
ea
day
;Ind
ivid
ual
Pre,
Aft
er10
ses-
sion
s(P
ost)
,3
mon
th(F
ollo
w-
up)
NR
S,T
ES,
BPI
,SH
CS,
SOPA
,C
ES–
D
Dai
lyav
erag
epa
in(N
RS)
∗H
ypno
sis
>
Bio
feed
back
[Pos
t]
Jens
en,
Bar
ber,
Rom
ano,
Mol
ton,
etal
.(2
009)
No
Hyp
nosi
sPr
ogre
ssiv
eM
uscl
eR
elax
atio
n10
sess
ions
;No
des
crip
tion
sab
outf
requ
ency
;In
div
idua
l;H
W=
liste
ning
toa
tape
din
stru
ctio
nat
leas
tonc
ea
day
;Ind
ivid
ual
Pre,
Aft
er10
ses-
sion
s(P
ost)
,3
mon
th(F
ollo
w-
up)
NR
S,T
ES,
BPI
,SH
CS
Dai
lypa
inin
tens
ity
com
posi
te(N
RS)
∗
Hyp
nosi
s>
PMR
[Pos
t],H
ypno
sis
>
PMR
[FU
]
Jone
set
al.
(200
6)Ye
sH
ypno
ther
apy
Supp
orti
veps
ycho
ther
apy
30m
in.×
12se
ssio
ns;
Var
iant
freq
uenc
y;H
W=
liste
ning
toa
tape
din
stru
ctio
n;In
div
idua
l
Bas
elin
e,W
eek
17(P
ost)
agl
obal
asse
ssm
ento
fch
estp
ain,
agl
obal
asse
ssm
ento
fw
ell-
bein
g,M
acN
ewQ
OL
inst
rum
ent,
Lin
ear
anal
ogue
Scal
e(P
ain
seve
rity
0–10
0),H
AD
Pain
seve
rity
(Lin
eran
alog
uesc
ale,
0-10
0)
Hyp
nosi
s>
Supp
orti
veps
ycho
ther
apy
[Pos
t]
(Con
tinu
ed)
9
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Tabl
e2
(Con
tinu
ed)
Stud
yR
CT
Inte
rven
tion
s
Sett
ings
ofH
ypno
tic
Inte
rven
tion
Ass
essm
ent
Poin
tM
easu
res
Pain
Ind
icat
ors
Res
ults
Pals
son
etal
.(2
002)
No
Hyp
nosi
sW
aiti
nglis
t45
min
.×7
sess
ions
;B
iwee
kly
(ove
r12
wee
ks);
HW
=lis
teni
ngto
ata
ped
inst
ruct
ion
dai
ly;I
ndiv
idua
l
Pre,
Wee
k2
(Pos
t),
4m
onth
(Fol
low
-up
)
the
Sym
ptom
dia
ry(b
owel
mov
emen
t:4-
poin
t,th
ew
orst
epis
ode
ofab
dom
inal
pain
&bl
oati
ng:
5-po
int)
,BD
I,SC
L–9
0R,S
PSI
The
seve
rity
ofth
ew
orst
epis
ode
ofab
dom
inal
pain
(5-p
oint
scal
epe
rd
ay;1
4d
ays
sym
ptom
sum
scor
es)
∗
Hyp
nosi
s>
Wai
ting
list[
Post
]
Spin
hove
net
al.
(199
2)
No
Self
-hyp
nosi
sA
utog
enic
Trai
ning
45m
in.×
4se
ssio
ns;
Biw
eekl
y;H
W=
liste
ning
toa
15-m
in.t
aped
inst
ruct
ion
twic
ed
aily
;Ind
ivid
ual
Pre,
Wee
k16
(Pos
t),
6m
onth
(Fol
low
-up
)
Hea
dac
heIn
dex
,G
loba
lPai
nra
ting
,SC
L–9
0,C
SQ
Pain
inte
nsit
y(H
ead
ache
Ind
ex)∗
No
sign
ifica
ntd
iffe
renc
esbe
twee
ntr
eatm
entg
roup
s[B
oth
Post
&FU
]
10
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ter
Kui
leet
al.
(199
4)
No
Cog
niti
vese
lf-h
ypno
sis
Aut
ogen
icTr
aini
ngW
aiti
nglis
t
60m
in.×
7se
ssio
ns;
Wee
kly;
HW
=lis
teni
ngto
a15
-min
.tap
edin
stru
ctio
ntw
ice
dai
ly;I
ndiv
idua
l
Pre,
Wee
k8
(Pos
t),
Wee
k35
or6
mon
th(F
ollo
w-
up)
Hea
dac
heIn
dex
(wei
ghed
6-po
intL
iker
tsc
ale)
,SC
L–9
0,SH
CS,
Hea
dac
heC
hara
cter
isti
csQ
uest
ionn
aire
,M
igra
ine
Ind
ex,
Trea
tmen
tE
xpec
tati
on(0
–200
%sc
ale)
Pain
inte
nsit
y(H
ead
ache
Ind
ex)∗
AT
>W
aiti
nglis
t[P
ost]
van
Dyc
ket
al.
(199
1)
No
Futu
re-o
rien
ted
hypn
otic
imag
ery
Aut
ogen
icTr
aini
ng
Tota
l150
min
.;4
sess
ion;
Var
iant
freq
uenc
y;H
W=
liste
ning
tota
ped
inst
ruct
ions
tota
l25
h(1
500
min
.);In
div
idua
l
Pre,
8w
eeks
(Pos
t)H
ead
ache
Dia
ry,
STA
I,SD
S,C
IS,
SHC
S
Pain
inte
nsit
y(H
ead
ache
Ind
ex)∗
No
sign
ifica
ntd
iffe
renc
esbe
twee
ntr
eatm
entg
roup
s[P
ost]
(Con
tinu
ed)
11
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Tabl
e2
(Con
tinu
ed)
Stud
yR
CT
Inte
rven
tion
s
Sett
ings
ofH
ypno
tic
Inte
rven
tion
Ass
essm
ent
Poin
tM
easu
res
Pain
Ind
icat
ors
Res
ults
Zit
man
etal
.(1
992)
No
Futu
re-o
rien
ted
hypn
otic
imag
ery
Futu
reor
ient
ed-i
mag
ery
Aut
ogen
icTr
aini
ng
Tota
l300
min
.;8
sess
ion;
Var
iant
freq
uenc
y;H
W=
liste
ning
tota
ped
inst
ruct
ions
tota
ling
49h
(294
0m
in.);
Ind
ivid
ual
Pre,
Wee
k8
(Pos
t),
6m
onth
(Fol
low
-up
)
Hea
dac
heD
iary
,ST
AI,
SDS,
VA
S(p
erce
ived
cred
ibili
tyof
the
trea
tmen
t;B
orko
vec
&N
au,1
972)
,the
neur
otic
ism
scor
eof
the
Dut
chPe
rson
alit
yQ
uest
ionn
aire
base
don
the
Cal
ifor
nia
Psyc
holo
gica
lIn
vent
ory
Pain
inte
nsit
y(H
ead
ache
Ind
ex)∗
Hyp
nosi
s>
AT
[FU
]
Not
e.T
heas
teri
sks
ofpa
inin
dic
ator
sre
fer
tost
udie
sca
lcul
atin
gpa
inin
tens
ity.
BD
I=
Bec
kD
epre
ssio
nIn
vent
ory;
BPI
=B
rief
Pain
Inve
ntor
y;C
ES–
D=
Cen
ter
for
Epi
dem
iolo
gic
Stud
ies
Dep
ress
ion
scal
e;C
IS=
Cre
ativ
eIm
agin
atio
nSc
ale;
CSQ
=C
opin
gSt
rate
gies
Que
stio
nnai
re;F
IQ=
Fibr
omya
lgia
Impa
ctQ
uest
ionn
aire
;FU
=Fo
llow
-Up;
HA
D=
Hos
pita
lanx
iety
and
dep
ress
ion
scal
e;H
GSH
S–A
=H
arva
rdG
roup
Scal
eof
Hyp
noti
cSu
scep
tibi
lity,
Form
A;H
W=
Hom
ewor
k;M
acN
ewQ
OL
inst
rum
ent=
Mac
New
Hea
rtD
isea
seH
ealt
h-R
elat
edQ
ualit
yof
Lif
eQ
uest
ionn
aire
;MPQ
=M
cGill
Pain
Que
stio
nnai
re;N
RS
=N
umer
ical
Rat
ing
Scal
e;PS
QI=
Pitt
sbur
ghSl
eep
Qua
lity
Ind
ex;S
CL
–60
=60
-ite
mve
rsio
nof
the
Sym
ptom
Che
ckL
ist;
SCL
–90
=90
-ite
mve
rsio
nof
the
Sym
ptom
Che
ckL
ist;
SDS
=Se
lf-r
atin
gD
epre
ssio
nSc
ale;
SF–3
6=
Med
ical
Out
com
esSt
udy
36-I
tem
Shor
t-Fo
rmH
ealt
hSu
rvey
;SH
CS
=St
anfo
rdH
ypno
tic
Clin
ical
Scal
e;SH
SS–C
=St
anfo
rdH
ypno
tic
Susc
epti
bilit
ySc
ale,
Form
C;
SOPA
=Su
rvey
ofPa
inA
ttit
udes
;SP
SI=
Stre
ss-r
elat
edPh
ysic
alSy
mpt
oms
Inve
ntor
y;ST
AI=
Stat
e-Tr
aitA
nxie
tyIn
vent
ory;
TE
S=
Trea
tmen
tExp
ecta
ncy
Scal
e;V
AS
=V
isua
lAna
logu
eSc
ale.
12
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HYPNOSIS FOR CHRONIC PAIN META-ANALYSIS 13
Only Gay, Philippot, and Luminet (2002) allowed for a comparisonbetween hypnosis and standard care at follow-up. Thus, we could notcalculate a difference in intervention efficacy at follow-up.
A comparison between hypnosis and other psychological interven-tions. We next examined the results for a comparison between hyp-nosis and other psychological interventions. Table 4 displays resultsfor the postintervention comparisons between hypnosis and other psy-chological interventions Table 5 also displays results for the follow-upcomparisons We pooled 11 studies that provided postintervention dataand six studies that provided follow-up data. These comparisons werenot significant, and effect sizes did not show a superior effect for hyp-nosis (postintervention, g = .04, 95% CI: –0.22–0.30, ns; follow-up, g =-.05, 95% CI: –0.33–0.23, ns). Heterogeneities were moderate (follow-up,Q = 10.02, ns; I2 = 30.16%) to large (postintervention, Q = 22.21, p < .05;I2 = 50.47%). These results indicate that the efficacy of hypnosis was notdifferent from that of other psychological interventions.
Comparing within a diagnostic group (headache or nonheadache).Furthermore, we explored the efficacy of hypnosis with respect tospecific diagnostic groups (headache group or nonheadache group)and the type of interventions. Jensen Barber, Romano, Hanley, et al.(2009) reported that pain intensity within a hypnosis group was sig-nificantly stronger than within a control group during a pretreatmentphase. We excluded Jensen, Barber, Romano, Hanley, et al. (2009) fromsubsequent analyses in order to more accurately discuss the efficacy ofhypnosis.
Within the headache group, we pooled four studies that pro-vided postintervention data and three studies that provided follow-up data. These comparisons did not produce significant results(postintervention, g = –.21, 95% CI: –0.44–0.03, ns; follow-up,g = –.06, 95% CI: –0.34–0.22, ns). However, the effect sizes revealeda small effect for other psychological interventions being more effica-cious than hypnosis at postintervention. Heterogeneities were relativelysmall (postintervention, Q = 2.28, ns; I2 = 0.00%; follow-up, Q = 2.26,ns; I2 = 0.00%).
Within the nonheadache group, we pooled six studies that providedpostintervention data and two studies that provided follow-up data.Effect sizes indicated a significant moderate effect (postintervention, g =.46, 95% CI: 0.16–0.75, p < .01) and an insignificant small effect (follow-up, g = .27, 95% CI: –0.20–0.74, ns) of hypnosis. Heterogeneities werealso rather small within both comparisons (postintervention, Q = 1.54,ns; I2 = 0.00%; follow-up, Q = 1.30, ns; I2 = 0.00%).
Comparing the type of intervention. We also examined results forcomparisons between hypnosis and three psychological treatments:
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Tabl
e3
Met
a-A
naly
sis
Com
pari
ngH
ypno
sis
Wit
hSt
anda
rdC
are
atP
osti
nter
vent
ion
Pha
se
Con
trol
Exp
erim
enta
l
Stud
yM
ean
SDN
Mea
nSD
NW
eigh
t(%
)g
ivt,
rand
om,9
5%C
I
Cas
tele
tal.
(200
9)7
1.01
75.
792.
0516
20.9
7%0.
64[−
0.27
,1.5
5]G
ayet
al.(
2002
)4.
231.
1410
1.85
1.65
1319
.71%
1.58
[0.6
1,2.
54]
Pals
son
etal
.(20
02)
16.8
3.6
912
.912
.39
1522
.94%
0.37
[−0.
46,1
.21]
ter
Kui
leet
al.(
1994
)25
.416
5322
.514
.840
36.3
8%0.
19[−
0.23
,.60
]To
tal(
95%
CI)
7984
100.
00%
0.60
[0.0
3,1.
17]
Not
e.iv
t=in
vers
e-va
rian
cew
ith
t2.H
eter
ogen
eity
:Q=
7.03
,df=
3(p
<.1
0):I
2=
57.3
0%;T
estf
orov
eral
leff
ect:
Z=
2.05
(p<
.05)
.
14
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nloa
ded
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] at
03:
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ugus
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5
Tabl
e4
Met
a-A
naly
sis
Com
pari
ngH
ypno
sis
Wit
hO
ther
Psy
chol
ogic
alIn
terv
enti
ons
atP
osti
nter
vent
ion
Pha
se
Con
trol
Exp
erim
enta
l
Stud
yM
ean
SDN
Mea
nSD
NW
eigh
t(%
)g
ivt,
rand
om,9
5%C
I
Abr
aham
sen
etal
.(20
09)
3.9
1.5
202.
92.
420
8.46
%0.
49[−
0.14
,1.1
2]A
brah
amse
net
al.(
2008
)54
.129
.64
1937
.325
.822
8.48
%0.
60[−
0.03
,1.2
2]C
aste
leta
l.(2
009)
6.1
2.52
165.
792.
0516
7.64
%0.
13[−
0.56
,0.8
3]G
ayet
al.(
2002
)2.
371.
6213
1.85
1.65
136.
74%
0.31
[−0.
47,1
.08]
Jens
en,B
arbe
r,R
oman
o,H
anle
y,et
al.(
2009
)3.
361.
2811
5.09
1.92
206.
67%
−0.9
8[−
1.76
,−0.
20]
Jens
en,B
arbe
r,R
oman
o,M
olto
n,et
al.(
2009
)4.
131.
697
3.17
1.75
155.
44%
0.53
[−0.
38,1
.45]
Jone
set
al.(
2006
)47
.31
26.5
513
29.1
325
.31
156.
81%
0.68
[−0.
09,1
.45]
Spin
hove
net
al.(
1992
)2.
51.
423
32.
123
9.15
%−0
.28
[−0.
86,0
.31]
ter
Kui
leet
al.(
1994
)16
.212
.141
22.5
14.8
4011
.37%
−0.4
6[−
0.90
,−0.
02]
van
Dyc
ket
al.(
1991
)48
.630
.628
48.1
48.2
279.
94%
0.01
[−0.
52,0
.54]
Zit
man
etal
.(19
92)–
148
.630
.628
52.9
48.7
249.
68%
−0.1
1[−
0.65
,0.4
4]Z
itm
anet
al.(
1992
)–2
48.1
48.2
2752
.948
.724
9.61
%−0
.10
[−0.
65,0
.45]
Tota
l(95
%C
I)24
625
910
0.00
%0.
04[−
0.22
,0.3
0]
Not
e.iv
t=in
vers
e-va
rian
cew
ith
t2.H
eter
ogen
eity
:Q=
22.2
1,df
=11
(p<
.05)
:I2
=50
.47%
,Tes
tfor
over
alle
ffec
t:Z
=0.
28(n
s).
Hyp
nosi
sis
com
pare
dw
ith
auto
geni
ctr
aini
ngin
“Zit
man
etal
.(19
92)–
1”an
dw
ith
futu
re-o
rien
ted
imag
ery
in“Z
itm
anet
al.(
1992
)–2.
”
15
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5
Tabl
e5
Met
a-A
naly
sis
Com
pari
ngH
ypno
sis
Wit
hO
ther
Psy
chol
ogic
alIn
terv
enti
ons
atFo
llow
-Up
Pha
se
Con
trol
Exp
erim
enta
l
Stud
yM
ean
SDN
Mea
nSD
NW
eigh
t(%
)g
ivt,
rand
om,9
5%C
I
Gay
etal
.(20
02)–
12.
751.
9113
1.66
1.49
139.
63%
0.62
[−0.
17,1
.41]
Gay
etal
.(20
02)–
22.
81.
6313
2.38
2.47
1310
.00%
0.19
[−0.
57,0
.97]
Jens
en,B
arbe
r,R
oman
o,H
anle
y,et
al.(
2009
)3.
131.
4211
4.9
2.13
209.
94%
−0.9
0[−
1.67
,−0.
13]
Jens
en,B
arbe
r,R
oman
o,M
olto
n,et
al.(
2009
)3.
351.
927
3.48
2.04
157.
87%
−0.0
6[−
0.96
,0.8
3]Sp
inho
ven
etal
.(19
92)
21.
720
2.5
2.6
2013
.63%
−0.2
2[−
0.85
,0.4
0]te
rK
uile
etal
.(19
94)
15.7
14.7
3719
.614
.235
19.4
7%−0
.27
[−0.
73,0
.20]
Zit
man
etal
.(19
92)–
150
.736
.621
41.6
51.8
2414
.72%
0.20
[−0.
39,0
.78]
Zit
man
etal
.(19
92)–
248
.839
.721
41.6
51.8
2414
.74%
0.15
[−0.
43,0
.74]
Tota
l(95
%C
I)14
316
410
0.00
%−0
.05
[−0.
33,0
.23]
Not
e.iv
t=in
vers
e-va
rian
cew
ith
t2.H
eter
ogen
eity
:Q=
10.0
2,df
=7
(ns)
:I2
=30
.16%
,Tes
tfor
over
alle
ffec
t:Z
=–0
.33
(ns)
.“G
ayet
al.
(200
2)–1
”m
eans
com
pari
son
betw
een
Hyp
nosi
sw
ith
PMR
at3-
mon
thfo
llow
-up
phas
e.“G
ayet
al.
(200
2)–2
”m
eans
com
pari
son
betw
een
Hyp
nosi
sw
ith
PMR
atth
e6-
mon
thfo
llow
-up
phas
e.H
ypno
sis
isco
mpa
red
wit
hau
toge
nic
trai
ning
in“Z
itm
anet
al.(
1992
)–1”
and
wit
hfu
ture
-ori
ente
dim
ager
yin
“Zit
man
etal
.(19
92)–
2.”
16
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HYPNOSIS FOR CHRONIC PAIN META-ANALYSIS 17
autogenic training (AT), guided imagery, and progressive muscle relax-ation (PMR). For AT, we pooled four studies with postinterventiondata and three studies with follow-up data. Comparisons with thesestudies were not significant (postintervention, g = –.23, 95% CI: –0.49–0.03, ns; follow-up, g = –.12, 95% CI: –0.44–0.19, ns), but AT wasslightly more effective than hypnosis. Heterogeneities were quite small(postintervention, Q = 2.09, ns; I2 = 0.00%; follow-up, Q = 1.61, ns; I2 =0.00%).
For guided imagery, we pooled three studies with postinterventiondata. This comparison with hypnosis was also insignificant(postintervention, g = .31, 95% CI: –0.13–0.74, ns), but the com-parison with guided imagery garnered a small-to-moderate effect infavor of hypnosis. The heterogeneity was moderate (postintervention,Q = 3.20, ns; I2 = 37.56%). Only Zitman, van Dyck, Spinhoven, andLinssen (1992) compared hypnosis with guided imagery at follow-up.Thus, we could not calculate a difference in efficacy between hypnosisand guided imagery at follow-up.
For PMR, we pooled two studies providing postintervention andfollow-up data. Both comparisons were insignificant (postintervention,g = .40, 95% CI: –0.19–0.99, ns; follow-up, g = .27, 95% CI: –0.20–0.74, ns).However, the effect sizes showed that hypnosis produced a small-to-moderate effect in comparison to PMR. Heterogeneities were relativelysmall (postintervention, Q = .14, ns; I2 = 0.00%; follow-up, Q = 1.30, ns;I2 = 0.00%).
Discussion
Main FindingsThe results showed that hypnosis was moderately effective for
managing chronic pain compared to a standard care during apostintervention phase. This result is consistent with those ofMontgomery et al. (2000). Montgomery and colleagues reported thathypnosis was moderately to largely efficacious for treatment of clin-ical pain and for ameliorating experimental pain (e.g., cold pressortest). Next, on the whole, our results revealed no differences in efficacybetween hypnosis and other psychological interventions during bothpostintervention and follow-up phases. According to our diagnosticgroups, hypnosis resulted in a significant moderate effect in compari-son to other psychological interventions within a nonheadache groupduring a postintervention phase. Further analysis suggested that hyp-nosis also resulted in superior efficacy during a follow-up phase. In theheadache group, hypnosis was no more efficacious than other psycho-logical interventions. Conversely, analysis of effect sizes suggested thatother psychological interventions were slightly more efficacious than
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18 TOMONORI ADACHI ET AL.
hypnosis during a postintervention phase. Based on treatment com-parison, effect size analysis indicated that AT had a slightly greatereffect when compared to hypnosis during a postintervention phase.However, hypnosis was slightly or moderately more effective thanguided imagery and PMR. Within these three comparison treatments,no significant differences emerged. Taken together, our results sug-gest that hypnosis is moderately more efficacious than standard careand other psychological interventions within nonheadache groups.Therefore, it appears that hypnosis can be an effective psychotherapyfor chronic pain.
Lunde, Nordhus, and Pallesen (2009) conducted a meta-analysis thatcompared CBT for chronic pain within an older adult sample and useda control group (a wait-list control and pretreatment group). This meta-analysis showed that CBT produced a small-to-moderate effect (d =0.47) during postintervention. In our analysis, hypnosis was moderatelyeffective as compared to standard care during a postintervention phase,and our effect size was greater than that obtained by Lunde et al. (2009).Thus, it is possible that hypnosis is more effective than CBT for manag-ing chronic pain when both hypnosis and CBT are compared to groupsthat do not conduct particular treatments.
Our results revealed no differences in efficacy between hypnosis andother psychological interventions for managing overall chronic pain.However, effect size analysis indicated that hypnosis was more effec-tive than other psychological interventions for a nonheadache group.Morley, Eccleston, and Williams (1999) and Eccleston, Williams, et al.(2009) investigated the efficacy of psychotherapies, especially CBT, formanaging chronic pain (excluding headache). These authors suggestedthat psychological treatments for headache are sufficiently differentfrom those used for other types of chronic pain. Morley et al. also saidthat “pain relief is a much more realistic result of treatment than inother chronic pain” (1999, p. 2). Morley and colleagues’ results showedthat CBT had a small, but greater, effect on managing chronic pain thanactive control groups receiving education, physiotherapy, occupationaltherapy, and treatment as usual (Morley et al., 1999, g = .29; Eccleston,Williams, et al., 2009; Standardized Mean Differences = –.14, a negativesign indicates a positive effect of CBT in their study). The effect sizeof our results exceeded those of Morley et al. and Eccleston, Williams,et al. when we compared hypnosis to other psychological interventionsin a nonheadache group during a postintervention. Thus, it is possiblethat hypnosis has superior efficacy to other psychological interventions,including CBT.
Although the differences were not significant, our results revealedthat other psychological interventions were more effective than hypno-sis for those suffering from headaches. During our systematic review,all studies investigating the efficacy of hypnosis for headache groups
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had substantial overlap with studies comparing the efficacy of hyp-nosis versus AT. Four studies compared hypnosis with AT during apostintervention phase and three studies compared these two treat-ments during a follow-up phase. This suggests that AT is more effica-cious than hypnosis for managing headaches. However, Kanji, White,and Ernst (2006) reported that AT and hypnosis are similarly effica-cious for the treatment of headaches. A meta-analysis of controlledclinical trials reported by Stetter and Kupper (2002) showed that ATfor headaches was weakly inferior to other psychological interventions(postintervention, g = −.25; follow-up, g = −.26). As mentioned above,there were inconsistent results between our results when compared toprevious studies. We need to further investigate differences in efficacybetween hypnosis and other psychological interventions (especially AT)for the treatment of headaches.
Our results indicated that hypnosis was more effective than guidedimagery and PMR for managing chronic pain; however, differencesin the effectiveness of hypnosis were not statistically significant. Ourresults are intriguing given that studies comparing hypnosis with thesetwo interventions through a meta-analysis had not been conductedbefore. There are a few systematic reviews comparing guided imageryand PMR with standard care or a wait-list control (Henschke et al., 2011;Posadzki, Lewandowski, Terry, Ernst, & Stearns, 2012). However, thesereviews did not reveal effect sizes compatible with our results. Furtherexploration will be needed to clarify differences in efficacy betweenhypnosis and guided imagery or PMR.
TA and HF rated methodological quality using procedures describedin Yates et al. (2005). All methodological quality indices revealed lowerscores as compared to previous studies (Eccleston, Palermo, et al., 2009;Eccleston, Williams, et al., 2009). High limits within design quality werelow, and items regarding allocation bias and power calculation scoresequal to 0 were observed in all 12 studies. These scores do not indi-cate that authors of the 12 studies did not perform proper randomallocation and power calculations. These indices only suggest that ade-quate description as to the procedures for random allocation and resultsof the power calculations prior to starting participant recruitment foreach study were not reported in all 12 studies. Decorrelations betweenmethodological quality, the year of publication, and the N at the endof treatment were also recorded. Methodological qualities of clinicalhypnotic intervention studies have remained at low levels, which isinconsistent with the date and the scale of study (i.e., the number ofstudy samples).
In general, people are likely to view hypnosis as a suspect methodand mental state. Clinicians and researchers who use hypnosis arealways required to seek sound evidence for the efficacy of theirtreatment. Some guidelines for improving the methodological quality
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of intervention studies have been suggested (i.e., the CONSORTguidelines; Begg et al., 1996; Moher et al., 2010; Moher, Schulz, &Altman, 2001). Controlling the researcher’s intent regarding the alloca-tion and power calculations is possible regardless of the vague natureof hypnosis. We suggest that procedures for random allocation and theresults of power analyses should be reported enough in future researcharticles. In future studies, researchers who seek sound evidence of hyp-notic efficacy should aspire to guarantee methodological quality to acertain targeted level in order to heighten the credibility of the results.
ImplicationsImplications for research. Although target diseases and study
designs are diverse, large heterogeneities reported in the current studyare related to the nature of hypnosis. There is ambiguity as to whethera hypnotic intervention from Study X and Study Y can specifically bedefined as “hypnosis.” Both studies might have different therapeuticmechanisms. Whether an altered state of consciousness is evoked by ahypnotic induction procedure is an area of controversy within researchon hypnosis. Using functional brain imaging, Rainville and colleaguesshowed that cerebral physiological changes are evoked by hypnosis(Hofbauer et al., 2001; Rainville, Bao, & Chrétien, 2005; Rainville et al.,1997). Whether an altered state of consciousness is evoked by a hypnoticinduction procedure needs future study. However, studies revealingthe nature of hypnosis from an empirical standpoint are important toextend the credibility of hypnotic techniques.
Although pain or pain intensity was defined as the main outcomein this study, studies have shown that hypnosis works well on boththe affective (Holroyd, 1996) and cognitive dimensions (Jensen et al.,2011) of pain. Perhaps we can better assess the multilateral efficacy ofhypnosis in order to define the unpleasantness of pain or a cognitivedimension of pain as the main outcome. Jensen and Patterson (2006)suggested, “the primary goal is not to alter pain during hypnosis, but tomake hypnotic suggestions and teach skills that will alter pain intensityand its impact throughout the patient’s daily life” (p. 96). Investigationof other outcomes beyond pain should be addressed in future studiesto better determine the efficacy of hypnosis.
Other psychological interventions assessed in our meta-analysisincluded AT, biofeedback, CBT, guided imagery, PMR, and support-ive psychotherapy. Some studies suggest that those interventions sharesimilar therapeutic components with hypnosis (e.g., relaxation andfocused attention; Gay et al., 2002; Jensen Barber, Romano, Hanley, et al.,2009; Jensen Barber, Romano, Molton, et al., 2009). AT is also regardedas a form of self-induced hypnotherapy (Schultz, 1987). Supportive psy-chotherapy reported by Jones, Cooper, Miller, Brooks, and Whorwell(2006) could be distinguished from hypnosis. Since the CBT used in
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Castel, Salvat, Sala, and Rull (2009) included several interventions, itis difficult to limit one component as the main intervention utilized intheir study. We could argue that other psychological interventions sam-pled in our study are regarded as hypnotic-like interventions, exceptfor the supportive psychotherapy reported in Jones et al. (2006) and theCBT reported in Castel et al. (2009). Given that most psychological inter-ventions in our study are regarded as hypnotic-like interventions, weneed to further examine a comparison of the efficacy between hypnotic-like interventions and less hypnotic-like interventions, such as in vivoexposure (Boersma et al., 2004; Vlaeyen, de Jong, Geilen, Heuts, &van Breukelen, 2002) and operant conditioning (Fordyce, Fowler, &DeLateur, 1968; Fordyce et al., 1973; Lindstrom et al., 1992). Such studieswould help clarify the therapeutic mechanisms of clinical hypnosis.
Implications for practice. Our results have demonstrated the effi-cacy of hypnosis in clinical studies. Below, we describe a few sugges-tions regarding the active clinical use of hypnosis.
The essential aspects of our results in terms of active clinical use ofhypnosis include the following:
• When compared with nonspecific interventions including a wait-listcontrol and a treatment as usual, hypnosis shows good efficacy formanaging overall chronic pain;
• Hypnosis led to larger effect sizes when compared to other psychologicalinterventions, including CBT, for managing nonheadache chronic pain;
• It is unclear whether hypnosis is more effective than other psychologicalinterventions for managing headaches.
From these, hypnosis should be promoted as an effective psycholog-ical intervention for managing chronic pain. We should use hypno-sis actively for intractable chronic pain, such as nonheadache pain.However, we do not have strong evidence for preferentially usinghypnosis to manage headaches.
Although our results showed that the efficacy of hypnosis might besuperior to CBT, the treatments do not have to be mutually exclusive.Kirsch, Montgomery, and Sapirstein (1995) reported that using hypnosisas an adjunct to CBT enhances treatment outcomes for clinical prob-lems, such as chronic pain. Castel, Cascon, Padrol, Sala, and Rull (2012)also conducted an RCT targeting fibromyalgia and reported that CBTwith hypnosis was more effective than just CBT alone. Thus, we suggestthat the combination of hypnosis and CBT could lead to more effectiveclinical treatment.
We need to consider the application of hypnosis within group set-tings. Eleven of our studies used hypnosis in individual settings, whileonly Castel et al. (2009) adopted a group setting. Vinogradov andYalom (1989) described the efficient use of resources and the cost
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effectiveness of group psychotherapy. Hypnosis within group settingshas been used to treat several diseases, such as allergies (Madrid,Rostel, Pennington, & Murphy, 1995), breast cancer (Butler et al., 2009;Spiegel & Bloom, 1983), depression (Butler et al., 2008), fibromyalgia(Castel et al., 2009, 2012), and posttraumatic stress disorder (Lesmana,Suryani, Jensen, & Tiliopoulos, 2009). These studies also reported theefficacy of hypnotic interventions. Although it is difficult to establish thebest-suited therapy for one patient or client, group interventions mightprovide an effective format to deliver hypnotherapy for chronic pain.
LimitationsFirst, results of our meta-analysis revealed large heterogeneities
between studies. Large heterogeneity distorts the reliability of ourresults. Efficacy of hypnosis might not have been clearly determinedbased on the current results. Second, it is possible that the current studydid not provide a pure comparison of hypnosis with other psychologi-cal interventions by including two studies (Castel et al., 2009; Zitmanet al., 1992). Therefore it is possible that we are overestimating theefficacy of hypnosis in our study.
Conclusions
The objective of this study was to demonstrate the empiricalefficacy of hypnosis. We observed that hypnosis was moderately effec-tive for managing chronic pain compared to a standard care duringa postintervention phase. Hypnosis was also effective when com-pared with other psychological interventions in a nonheadache group.However, the methodological quality of individual studies was ratherlow. Large heterogeneities were also observed. Future studies shouldimprove upon methodological quality and heterogeneity to betterdetermine the efficacy of hypnosis for chronic pain management.
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AppendixSearch strategy
1. Medline
1. randomized controlled trial.pt.2. randomized Controlled Trial/3. Randomized Controlled Trial as Topic/4. Controlled clinical trial.pt.5. Clinical trial.pt.6. Clinical Trial/7. Clinical Trial as Topic/8. Random Allocation9. Double-Blind Method/
10. Single-Blind Method/
11. Comparative Study/
12. Empirical Research/
13. Treatment Outcome/14. Comparative Effectiveness Research/
15. or/1-1416. exp Hypnosis/17. exp ∗Pain/
18. 15 and 16 and 1719. Remove duplicates from 1820. Limit 19 to English language21. Limit 20 to “review articles”22. 20 not 21
2. CENTRAL
1. Medical Subject Heading descriptor Pain explode all trees2. (pain∗):ti,ab,kw3. MeSH descriptor Hypnosis explode all trees4. (hypnos∗):ti,ab,kw5. (#1 OR #2)6. (#3 OR #4)7. (#5 OR #6)
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3. PsycINFO
1. exp ∗Pain/
2. exp Hypnosis/3. 1 and 24. limit 3 to English language5. limit 4 to all journals
Eine Meta-Analyse zu Hypnose bei Chronischen Schmerzsyndromen –EinVergleich zwischen Hypnose, Standardbehandlung und anderen
psychologischen Interventionen
Tomonori Adachi, Haruo Fujino, Aya Nakae, Takashi Mashimo undJun Sasaki
Abstrakt: Hypnose ist als effektive Behandlung psychologischer und phys-iologischer Beschwerden angesehen. Dennoch wurde die Effizienz alsStrategie zur Behandlung chronischen Schmerzes bisher noch nicht durchmeta-analytische Methoden bewertet. Das Ziel der aktuellen Studie wardie Durchführung einer Metaanalyse, um die Effizienz der Hypnoseim Management chronischen Schmerzes zu erheben. Verglichen mit derStandardbehandlung zeigte die Hypnose einen leichten Behandlungsvorteil.Außerdem zeigte die Hypnose einen leichten Vorteil im Vergleich mitanderen psychologischen Interventionen bei einer Nicht-Kopfschmerz-Gruppe. Die Ergebnisse lassen daarfu schließen, daß Hypnose bei derBehandlung chronischen Schmerzes effizient ist. Es wurde eine großeHeterogenität der eingeschlossenen Studien festgestellt. Die Natur derHypnosebehandlung wird weiterhin diskutiert.
Stephanie Reigel, MD
Une méta-analyse de l’hypnose dans les cas de douleurs chroniques - unecomparaison entre l’hypnose, les soins habituels et d’autre
interventions psychologiques
Tomonori Adachi, Haruo Fujino, Aya Nakae, Takashi Mashimo etJun Sasaki
Résumé: L’hypnose est considérée comme un traitement efficace des affec-tions psychologiques et physiques. Pourtant, son efficacité comme stratégiede gestion de la douleur chronique n’a pas été évaluée par des méthodesméta-analytiques. L’objectif de cette étude consistait à mener une méta-analyse afin d’évaluer l’efficacité de l’hypnose dans la gestion de la douleurchronique. Comparativement aux soins standards, l’hypnose en tant quetraitement était modérément bénéfique. De plus, le traitement par l’hypnoses’est révélé supérieur à la moyenne, comparativement à d’autres interven-tions psychologiques auprès d’un groupe ne souffrant pas de maux de tête.Ces résultats semblent indiquer que l’hypnose est efficace dans la gestionde la douleur chronique. Étant donné la grande hétérogénéité des études
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28 TOMONORI ADACHI ET AL.
comprises dans cette recherche, la nature du traitement par l’hypnose y estlonguement examinée.
Johanne ReynaultC. Tr. (STIBC)
Un meta-análisis de la hipnosis para problemas de dolor crónico: Unacomparación entre hipnosis, tratamiento estándar, y otras
intervenciones psicológicas
Tomonori Adachi, Haruo Fujino, Aya Nakae, Takashi Mashimo, yJun Sasaki
Resumen: La hipnosis es considerada como un tratamiento efectivo paraenfermedades físicas y psicológicas. Sin embargo, su eficacia como estrate-gia para el manejo de dolor crónico no ha sido evaluada a través de métodosmeta-analíticos. El objetivo del presente estudio fue la realización de unmeta-análisis para evaluar la eficacia de la hipnosis para el manejo de dolorcrónico. Al compararla con el tratamiento estándar, la hipnosis brindó un ben-eficio moderado. La hipnosis también mostró un efecto superior moderadoal compararla con otras intervenciones psicológicas para un grupo que nopadecía dolores de cabeza. Los resultados sugieren que la hipnosis es eficazpara el manejo de dolor crónico. Considerando la gran heterogeneidad de losestudios incluidos, se profundiza en la discusión sobre la naturaleza de lahipnosis como tratamiento.
Omar Sánchez-Armáss Cappello, PhDAutonomous University of San Luis Potosi,Mexico
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