EFFICACY OF PEER SUPPORT INTERVENTIONS
FOR DEPRESSION:
A META-ANALYSIS
Paull N
P
N. Pfeiffer,
Pf iff MD
University of Michigan, Dept. of Psychiatry
VA Ann Arbor HSR&D/SMITREC
Introduction
Challenge of Depression
16/6%
Lifetime/annual prevalence of major /
depressive disorder, U.S. general population1
No. 1
Projected cause of disability worldwide by 20302

5-20 times
Risk of suicide compared to general Risk
of suicide compared to general
population3

$83 billion
Cost to U.S. in 20004


1:Kessler JAMA 2003; 2:WHO 2008; 3:CDC & Harris BJP 1997; 4:Greenberg JCP 2003
Current Treatment Limitations

Antidepressants and Psychotherapy
 Small
S ll
12
tto moderate
d t effect
ff t sizes
i 1,2
 Treatment
 Time
to effectiveness
 Access

resistance3
barriers4
Additional services needed
1: Turner NEJM 2008; 2: Cuijpers BJP 2010; 3: Rush AJP 2006; 4: Chermack Medical Care 2008
Peer-based
Peer
based Interventions


Recommended by DHHS, President’s New Freedom
Commission to be included in recovery-base care
“Bring together individuals with similar stressors or
h l h problems
health
bl
in order
d to provide
d additional
dd
l
social support”

Many varied forms

Affordable, Accessible, Available, Acceptable1
1: Kessler Social Policy 1997
Question of Efficacy

Prior reviews show limited/mixed
/
evidence in:
 General
 Alcohol
medical conditions (i(i.e.
e cancer)1
dependence: Alcoholics Anonymous2
 Serious
Mental Illness: Recovery Inc (now
international) GROW3, DBSA
international),

No prior systematic reviews for depression--likely
limits psychiatrist referrals to services4
1: Barlow Int J Group Psychother 2000; 2: Ferri Cochrane 2006; 3: Davidson Clin Psychol-Sci Prac
1999; 4: Powel Psych Services 2000
Methods
Study Inclusion Criteria

Randomized controlled trials

Depressed indi
individuals
id als


A peer
peer-based
based intervention compared to either usual
care or psychotherapy
Pre and post depression measurement
Search/Selection Strategy


Databases: Medline, Psycinfo, CINAHL, CENTRAL
Search terms:
terms MeSH and free text
te t terms related to
Depression and Peer/Self-Help/mutual support

Limits: adults, peer-review, clinical trial

Also searched reference lists of included studies

References
f
reviewed by 2 independent reviewers
Data Abstraction

Study population characteristics

P
Peer
intervention
i
i characteristics
h
i i

Pre and post-depression
post depression scores

Sources of internal bias (i.e. Quality measures)
 Randomization procedure
 Blinding
Bli di off raters,
t
procedure
d
for
f blinding
bli di
 Description of participant drop-outs
Analyses

Pooled effects (standardized mean difference)
 DerSimonian

Heterogeneity
 Cochran’s

Q test of heterogeneity and I2
“Intention
Intention to treat
treat”
 Assumed

Laird Random Effects model
no change from baseline among dropouts
Influence analysis
 Omitted
one study at a time (test for outliers)
Analyses

Publication bias
 Contour-enhanced
funnels plots, Begg and Mazumdar
adjusted rank correlation test, Egger regression
asymmetry test

Stratified analyses based on gender, age,
d
depression
i measure, blinded
bli d d assessmentt
Results
Figure 1: Selection of Studies
Search of Relevant Databases
Medline: 203
references
PsycINFO: 417
references
CENTRAL: 142
references
CINAHL: 34
references
194 Duplicates
excluded
602 Unique
studies
t di for
f
review
457 excluded: not a
randomized controlled
trial
120 excluded: participants
p
p
not depressed, or baseline
depression not reported
10 Studies met
inclusion
criteria
10 excluded: intervention
was not peer support
5 excluded: no usual care
or psychotherapy control
Table 1. Characteristics of Randomized Trials of Peer Support Interventions for Depression
Depression
p
%
Mean
Outcome
Study
N
Female
Age
Primary Study Inclusion criteria
Measure
Ayen I. et al,
51
100
46-56
BDI > 13, no menstrual period in
BDI
2004
(range)
last 12 months
Peer Support
Intervention
12 session weekly
PSG
Bright JI. et
al,
l 1999
98
71
46
HSRD > 10
BDI, HRSD
10 session weekly
PSG
Chen CH. et
al, 2000
60
100
29
BDI > 9/10, post-partum
BDI
Dennis CL.,,
2009
701
100
20-34
(median)
EPDS > 9,, post-partum
p
p
EPDS
Evans RL. et
al, 1995
78
32
54
CES-D > 15, stage II cancer with
planned XRT
CES-D
Kelly JA. et
al, 1993
68
0
34
CES-D
CES
D > 15, HIV positive
CES-D
CES
D
8 session weekly
PSG
CBT, Usual care
Maynard CK.
et al, 1993
34
100
45
Depressed women (selfidentified)
BDI
12 session weekly
PSG
CBT, Usual care*
Michielin P
P.
et al, 2007
40
Not
reported
56 59
56-59
BDI > 9
9, caregiver for someone
with serious mental illness
BDI
10 session PSG
over 15 weeks
CBT
Ong Y. et al,
1987
20
85
74
Depressed elderly patients
(Feighner research criteria)
following inpatient stay
Zung
depression
scale
9 months weekly
PSG
Usual care
Verduyn C.
et al, 2003
119
100
30
BDI > 14 , mother of pre-school
aged child
BDI, HRSD
16 session weekly
PSG
Control Condition(s)
CBT, Usual care
CBT
4-5 session
weekly PSG
Usual care
~10 weeks
telephone peer
mentor
8 session weekly
PSG
Usual care
CBT, Usual care
CBT, Usual care
PSG = Peer support group, CBT = group cognitive behavioral therapy, BDI = Beck Depression Inventory, CES-D = Center for Epidemiological Studies Depression scale
EPDS = Edinborough Postpartum Depression Scale, HRSD = Hamilton Rating Scale for Depression, HRSD = Hamilton Rating Scale for Depression
*P ti t were nott randomized
*Patients
d i d tto thi
this condition
diti and
d therefore
th f
it was excluded
l d d from
f
the
th meta-analyses
t
l
Peer Support vs. Usual Care
SMD (95% CI)
Percent
Weight
Ayen
-1.95 (-2.87, -1.02)
9.81
Ch
Chen
-0.71
0 71 ((-1.23,
1 23 -0.19)
0 19)
16 06
16.06
Evans
-0.83 (-1.44, -0.22)
14.45
Kelly
-0.70 (-1.36, -0.03)
13.56
Subtotal (I-squared
(I squared = 48
48.5%,
5% p = 0
0.121)
121)
-0 95 (-1
-0.95
(-1.41,
41 -0.49)
-0 49)
53 89
53.89
-0.21 ((-0.37,, -0.05))
22.06
0.07 (-0.81, 0.95)
10.41
Verduyn
-0.25 (-0.91, 0.41)
13.64
Subtotal (I-squared = 0.0%, p = 0.815)
-0.21 (-0.36, -0.05)
46.11
Overall (I-squared = 70.8%, p = 0.002)
-0.59 (-0.98, -0.21)
100.00
Author of Study
Not Blinded
Blinded
Dennis
Ong
NOTE:
O
Weights
e g ts are
a e from
o random
a do e
effects
ects a
analysis
a ys s
-2
-1
Favors Peer Support
0
1
2
Favors Usual Care
Peer Support vs. Group CBT
Author of Study
SMD (95% CI)
Percent
g
Weight
Not Blinded
0.60 (0.03, 1.18)
14.42
Bright
g (p
(professional -led g
groups)
p )
0.32 ((-0.30,, 0.95))
13.07
Bright (paraprofessional -led groups)
-0.35 (-1.11, 0.42)
10.22
Evans
-0.29 (-0.87, 0.28)
14.47
Kelly
-0.36 (-1.01, 0.29)
12.51
Maynard
1.03 (-0.06, 2.12)
5.95
Michielin
0.24 (-0.38, 0.86)
13.19
Subtotal (I -squared = 47.8%, p = 0.074)
0.12 (-0.23, 0.47)
83.82
Verduyn
-0.02 (-0.54, 0.49)
16.18
Subtotal (I -squared = .%, p = .)
-0.02 (-0.54, 0.49)
16.18
Overall (I -squared = 40.1%, p = 0.111)
0.10 (-0.20, 0.39)
100.00
Ayen
Blinded
NOTE: Weights are from random effects analysis
-2
-1
Favors Peer Support
0
1
2
Favors Group CBT
Other Results



Intention-to-treat and Influence analyses did not
change results
No publication bias evident by Egger or Begg test
or visuall inspection off funnel
f
l plot.
l
Study quality:
quality
 All
reported treatment drop-outs
 3 of 10 single-blinded
 3 of 10 described randomization process
Discussion
Conclusion


DHHS and the President’s New Freedom
Commission: peer support should be part of
recovery-based mental health care
RResults
l provide
d RCT evidence
d
to support these
h
initiatives with regard to depression
Limitations

Heterogeneity among studies
 Statistically
accounted for by blinding
 May not be generalizable


Usual care and fidelity of group CBT not reported
PPotential
t ti l for
f bias
bi in
i iindividual
di id l studies
t di (moderate
( d t
quality), publication bias (though not detected), and
among reviewers
i
((nott bli
blinded)
d d)
Take Homes



Peer interventions for depression are underresearched
Available evidence suggests peer support may be
superior
i to
t usuall care and
d similar
i il tto group CBT
More research is needed to establish effectiveness
and optimal delivery

HSR&D/SMITREC Researchers (Valenstein) currently conducting
RCT of mutual telephone-based peer support
Acknowledgments

Collaborators:
 Marcia
Valenstein
 Mary Rogers
J
John Piette
 Michele Heisler