Content uploaded by Takayoshi Koide
Author content
All content in this area was uploaded by Takayoshi Koide on Feb 20, 2014
Content may be subject to copyright.
Available via license: CC BY 4.0
Content may be subject to copyright.
Prospective Study on the Association between Harm
Avoidance and Postpartum Depressive State in a
Maternal Cohort of Japanese Women
Kaori Furumura
1.
, Takayoshi Koide
1.
, Takashi Okada
1
*, Satomi Murase
1
, Branko Aleksic
1
,
Norika Hayakawa
1,2
, Tomoko Shiino
1
, Yukako Nakamura
1
, Ai Tamaji
1
, Naoko Ishikawa
1
, Harue Ohoka
1
,
Hinako Usui
1
, Naomi Banno
1
, Tokiko Morita
1
, Setsuko Goto
3
, Atsuko Kanai
4
, Tomoko Masuda
5
,
Norio Ozaki
1
1Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan, 2Faculty of Policy Studies, Nanzan University, Seto, Aichi, Japan,
3Department of Nursing, Sugiyama Jogakuen University, Nagoya, Aichi, Japan, 4Graduate School of Education and Human Development, Nagoya University, Nagoya,
Aichi, Japan, 5Graduate School of Law, Nagoya University, Nagoya, Aichi, Japan
Abstract
Background:
Recent studies have displayed increased interest in examining the relationship between personality traits and
the onset, treatment response patterns, and relapse of depression. This study aimed to examine whether or not harm
avoidance (HA) was a risk factor for postpartum depression measured by the Edinburgh Postnatal Depression Scale (EPDS)
and the state dependency of HA.
Methods:
Pregnant women (n = 460; mean age 31.964.2 years) who participated in a prenatal program completed the
EPDS as a measure of depressive state and the Temperament and Character Inventory (TCI) as a measure of HA during three
periods: early pregnancy (T1), late pregnancy (around 36 weeks), and 1 month postpartum (T2). Changes in EPDS and HA
scores from T1 to T2 were compared between the non depressive (ND) group and the postpartum depressive (PD) group.
Results:
There was no significant difference in the level of HA between the ND and PD groups at T1. In the ND group, EPDS
and HA scores did not change significantly from T1 to T2. In the PD group, both scores increased significantly from T1 to T2
(EPDS, p,0.0001; HA, p,0.048). In the ND and PD groups, a significant positive correlation was observed in changes in
EPDS and HA scores from T1 to T2 (r = 0.31, p = 0.002).
Conclusions:
These results suggest that HA cannot be considered a risk factor for the development of postpartum
depression measured by EPDS. Furthermore, HA may be state dependent.
Citation: Furumura K, Koide T, Okada T, Murase S, Aleksic B, et al. (2012) Prospective Study on the Association between Harm Avoidance and Postpartum
Depressive State in a Maternal Cohort of Japanese Women. PLoS ONE 7(4): e34725. doi:10.1371/journal.pone.0034725
Editor: Marianna Mazza, Catholic University of Sacred Heart of Rome, Italy
Received February 1, 2012; Accepted March 9, 2012; Published April 10, 2012
Copyright: ß2012 Furumura et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: Funding for this study was provided by research grants from the Ministry of Education, Culture, Sports, Science and Technology of Japan (http://www.
mext.go.jp/english/), the Ministry of Health, Labor and Welfare of Japan (http://www.mhlw.go.jp/english/), the Academic Frontier Project for Private Universities,
Comparative Cognitive Science Institutes, Meijo University (http://www.meijo-u.ac.jp/english/index.html), and an Intramural Research Grant (21B-2) for
Neurological and Psychiatric Disorders from the National Center of Neurology and Psychiatry (http://www.ncnp.go.jp/research/cost.html). The funders had no role
in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.
* E-mail: okada@med.nagoya-u.ac.jp
.These authors contributed equally to this work.
Introduction
Recent studies have displayed increased interest in examining
the relationship between personality traits and the onset, treatment
response patterns, and relapse of depression [1,2,3]. Personality
traits have been demonstrated to play an important role in the
onset of major depression, and have been considered useful as a
possible outcome for the prevention and early detection of and
intervention for symptoms of depression. A recent study
demonstrated that psychosocial adversity interacts with neuroti-
cism in the etiology of major depression, and the impact of
neuroticism on illness risk is greater at high than at low levels of
adversity [4].
On the other hand, previous studies have examined the
relationship between depression and personality as well as changes
in personality traits due to the onset of depression and have
demonstrated a significant association [5,6,7,8]. In a previous
study, our colleagues examined the state dependency of the
Temperament and Character Inventory (TCI) [9] in patients with
major depression [7] and reported that harm avoidance (HA), an
anxiety-related trait associated with neuroticism, decreased as
symptoms of depression improved in patients with major
depressive disorder (MDD). However, these patients were
PLoS ONE | www.plosone.org 1 April 2012 | Volume 7 | Issue 4 | e34725
medicated with antidepressants; therefore, there may be state
dependency of personality traits regarding depression [7].
Most previous studies that have explored the relationship
between personality traits and depression have done so after the
onset of depression or when medical intervention was already
underway. To date, only a handful of studies have examined the
association between personality and symptoms of depression
before the onset of depression. Thus, studies examining the
relationship between personality and the development of depres-
sion within a prospective cohort design should consider the
following three points: 1) the longitudinal changes in personality
traits through measured assessments or observations; 2) the effects
of changes in depression or symptoms of depression within a
continuous spectrum in order to capture individuals that fall
underneath beneath the threshold); and 3) the heterogeneity in the
pathophysiology of depression within individuals diagnosed with
having MDD.
However, previous prospective cohort studies that examined the
relationship between personality and depression did not take into
account the instability of personality within a longitudinal
timeframe, and assessed depression using a categorical (mental
disorder present or not present) approach. Additionally, previous
studies did not explore the heterogeneity found in participants
diagnosed with MDD, for example, by examining qualitative
differences within individuals diagnosed with MDD.
Postpartum depression is a specific type of depression used to
describe a continuum of depressive symptoms and diagnosis that
occur from several weeks to several months after childbirth. The
operational definition given in the Diagnostic and Statistical Manual of
Mental Disorders,Fourth Edition Text Revision uses a time frame of 4
weeks after childbirth for the onset of symptoms. We previously
conducted a prospective study on a maternal cohort of Japanese
women using a longitudinal design and a questionnaire to
elucidate the prevalence of postpartum depression (measured by
the EPDS), changes in depression symptoms, and biopsychosocial
factors affecting the onset of depressive state during pregnancy and
postpartum period [10].
The present study using a maternal cohort of pregnant Japanese
women is suitable to study personality traits associated with the
onset of depressive symptoms for the following three reasons: 1) we
can evaluate whether or not participants had postpartum
depression within a relatively short period (about 1 year) because
pregnant women are susceptible to the development of postpartum
depression and the incidence of postpartum depression is high
(approximately 10–15%) [11,12,13,14,15,16,17]; 2) we can
investigate how changes in depressive symptoms in unaffected
participants affects personality traits because using prospective
design we can detect depressive symptoms and personality traits
before onset of depression; and 3) in our cohort, subjects who
presented with depressive symptoms were more homogeneous
than MDD patients from previous studies because life events
influencing the onset of depression included common biopsycho-
social events (pregnancy and childbirth). To the best of our
knowledge, there have been no prospective cohort studies that
have investigated the role of personality in the onset of postpartum
depression.
Thus, the present study aimed to examine the relationship
between personality and depressive state to elucidate 1) whether
HA was a risk factor for postpartum depression and 2) whether or
not mean levels in HA changed before and after the onset of
depressive state, that is, to investigate the state dependency of HA.
Results
Participant profiles are shown in Table 1. No significant
differences in age were found across the four groups (p = 0.81,
ANOVA). There was no significant difference in HA during T1
(early pregnancy) between the ND and PD groups (Table 2).
Changes in EPDS from T1 to T2 are shown in Table 3 and Figure
S1. In the PD group, EPDS score increased significantly from T1
to T2. Changes in HA from T1 to T2 are shown in Table 4 and
Figure S2. In the PD group, HA score also increased significantly
from T1 to T2. The effect size of the HA change was smaller than
the EPDS change. Correlations between changes in scores on the
EPDS and HA are shown in Table 5 and Figure S3. Correlations
between changes in scores on the EPDS and HA were significant
(r = 0.31, p = 0.002). Regarding the HA subscales, only changes in
fatigability and asthenia was significantly correlated with changes
in EPDS scores (r = 0.29, p = 0.003) (Table 5).
Discussion
This study is the first to investigate the relationship between HA
and postpartum depression measured by EPDS prospectively in a
cohort of pregnant Japanese women. The systematic, longitudi-
nally collected information and subsequent analysis in the current
study brings new information regarding the understanding the
mental state dynamics of women from pregnancy to postpartum.
We investigated HA levels and depressive state before and after
childbirth to assess the role of HA as a risk factor for the
development of depressive symptoms prospectively. Moreover, we
assessed the levels of HA among mothers that experienced
depressive state only after delivery (ie, the TG and CD groups
were excluded). We observed different sequences over time
regarding the depressive state that might indicate a different
etiology of depression during pregnancy and postpartum depres-
sion. These differences were not recognized in previous studies,
because the previously used postpartum depressive group included
women who belonged to the CD group. In addition, as the women
included in TG and CD groups may have suffered from mood
disorders including MDD or bipolar disorder, we excluded those
groups from the current analyses. This exclusion was one of the
strengths of our study.
The sample size used in the current study was large and bias
effects (ie, recall/reporting bias) were relatively small as prospec-
tive design was used in the current study. Moreover, as all subjects
were Japanese, genetic and cultural confounders were negligible.
Results demonstrated that there were no differences in mean
levels of HA between the ND and PD groups at T1. Thus, our
results suggest that HA may not be a significant risk factor for the
development of postpartum depression measured by EPDS.
Furthermore, our findings indicated that HA may increase
according to increase of severity of depressive symptoms (the state
dependency of HA) due to significantly positive correlations in
changes of EPDS and HA from T1 to T2. In addition, we
observed the most significant correlation between EPDS change
and Fatigue/Asthenia subscale of HA. Although in order to
explore this findings it may be necessary to have additional
covariables that could contribute to the association between
Fatigue and Asthenia and EPDS, it is of note that the levels of
Fatigue and Asthenia may be elevated due to the pregnancy and
child birth experience [18]. Therefore, we speculate that this may
result in the strongest association between EPDS and Fatigue/
Asthenia.
This study had several limitations. First, we evaluated women’s
mental states only with a self-administered questionnaire.
Additionally, histories regarding mood disorders before pregnancy
Harm Avoidance and Postpartum Depressive State
PLoS ONE | www.plosone.org 2 April 2012 | Volume 7 | Issue 4 | e34725
were not assessed, and the ND and PD group also might include
people with bipolar disorder [19,20]. Future studies may find it
helpful to assess histories of mood disorders using diagnostic tools
such as the SCID in groups with postpartum depression.
In conclusion, this prospective study suggests that high HA, a
personality trait, observed during pregnancy may not be a
significant risk factor for the development of postpartum
depression measured by EPDS. Furthermore, our findings
demonstrate that levels of HA may increase according to the
onset of depressive symptoms (the state dependency of HA), and
decrease as a result of improvement in symptoms of depression.
Additional investigations into the state dependency of additional
personality traits that are purported to be linked to the onset of
MDD are needed.
Materials and Methods
Participants
This study was approved by the Ethics Committees of the
Nagoya University Graduate School of Medicine and associated
institutes and hospitals. Written informed consent was obtained
from all participants after the study was described to them in full
detail. Participants in this study consisted of women who attended
the prenatal program during pregnancy (starting before the 25th
week) at two obstetrical hospitals between August 2004 and
October 2010. The hospitals were located in the local adminis-
trative center of the city of Nagoya (with a population of
approximately 2 million people). Participants were randomly
selected from the obstetric hospital. Mothers with previous history
of mental problems or current treatment for mental problems were
excluded from the study, as well as mothers suffering from
neonatal pathology, born before 32 weeks of pregnancy. The
follow-up period was 6 months after the delivery [10]. Participants
were asked to complete self-reported questionnaires about
depression and personality (namely, HA traits) at home according
to a predetermined schedule.
A total of 647 adults ($20 years) were recruited for the study.
All subjects were Japanese. Several participants were excluded for
various reasons including lack of information on age (n = 4);
incomplete data on HA scores on the TCI (n = 7); incomplete
EPDS (n = 160); and incomplete other data (n = 16). Thus, a total
of 460 participants (mean age, 31.964.2 years; range, 20–44 years)
were included.
Table 1. Participant profiles in the four groups.
period
pregnancy postpartum
groups T1 late T2 n % age p-value
a
mean SD
Non depressive (ND) group 22 2331 72.0 31.9 4.1 0.81
Postpartum depressive (PD) group 22 +48 10.4 32.0 3.9
Temporary gestational depressive (TG) group ++ 252 11.3 31.8 5.1
+22
2+2
Continuous depressive (CD) group ++ +29 6.3 31.1 4.7
+2+
2++
All 460 100.0 31.9 4.2
+: EPDS.8, 2: EPDS,9.
T1: early pregnancy (before 25 weeks).
late: late pregnancy (around 36 weeks).
T2: postpartum (1 month).
a
: ANOVA was used to test the mean differences of age within the four groups.
doi:10.1371/journal.pone.0034725.t001
Table 2. HA scores in the ND and PD groups at T1.
n mean SD p-value
a
ND group 331 10.2 4.5 0.60
PD group 48 11.0 4.6
All 379 10.3 4.5
ND group: non depressive group.
PD group: postpartum depressive group.
SD: standard deviation.
a
: Student’s t-test was conducted in HA scores between the ND and PD groups
at T1.
doi:10.1371/journal.pone.0034725.t002
Table 3. EPDS scores in the ND and PD groups.
T1 T2 p-value
a
Cohen’s d
n mean SD mean SD
ND group 331 2.8 2.4 2.6 2.3 0.27 20.09
PD group 48 4.0 2.2 12.2 3.4
,
0.0001 2.86
All 379 2.9 2.4 3.8 4.0
EPDS: Edinburgh Postnatal Depression Scale.
T1: early pregnancy (before 25 weeks).
T2: postpartum (1 month).
ND group: non depressive group.
PD group: postpartum depressive group.
SD: standard deviation.
a
: Paired t-test in EPDS between T1 and T2 in the ND and PD groups.
doi:10.1371/journal.pone.0034725.t003
Harm Avoidance and Postpartum Depressive State
PLoS ONE | www.plosone.org 3 April 2012 | Volume 7 | Issue 4 | e34725
Study design
Depressive state (measured by EPDS) and HA were evaluated
from early pregnancy to 1 month after postpartum. Depressive
state (measured by EPDS) and HA were measured using the EPDS
and TCI, respectively. Participants were divided into the following
four groups according to severity of depressive symptoms from
early pregnancy to 1 month after childbirth as same as our
previous study [10]: group 1, non depressive (ND) group (mothers
scoring below EPDS threshold in all 3 time points) (n = 331); group
2, postpartum depressive (PD) group (mothers scoring above
EPDS threshold only at T2) (n = 48); group 3, temporary
gestational depressive (TG) group (mothers scoring above EPDS
threshold only during pregnancy) (n = 52); and group 4, contin-
uous depressive (CD) group (mothers scoring above EPDS
threshold during both pregnancy and postpartum) (n = 29)
(Table 1).
EPDS scores obtained during the following three periods were
used to classify participants into the four aforementioned groups:
early pregnancy (before 25 weeks, T1), late pregnancy (around 36
weeks), and 1 month postpartum (T2). The merit of this
classification is to distinguish groups that did not present with
symptoms of depression during pregnancy (ND and PD groups)
from groups that presented with depressive symptoms during
pregnancy (TG and CD groups). Because depressive symptoms
were evaluated only at postpartum in most previous studies, the
NG and TG groups were combined into a single group and the
PD and CD groups were combined into a single group.
Differences in HA scores during T1 were compared between
the ND and PD groups to evaluate whether levels of HA in
pregnant women served as a risk factor for postpartum depression.
The present study did not use structured interviews such as the
Structured Clinical Interview for DSM Disorders (SCID) to
confirm a history of mood disorders. The TG and CD groups were
excluded from these analyses because these groups may include
people with mood disorders, including MDD or bipolar disorder.
A total of 379 participants (ND, n = 331; PD, n = 48) were
included in these analyses.
Next, the association in the change between EPDS and HA
scores was examined in the ND and PD groups to evaluate
whether HA levels increased as EPDS increased from T1 to T2,
that is, we measured the state dependency of HA. In this analysis
we included 99 participants (ND, n = 81; PD, n = 18; mean age,
32.264.1 years; range, 24–44) who submitted HA scores both at
T1 and T2. To note, there was a discrepancy in the number of
subjects with HA scores between T1 and T2 due to the fact that
HA was not assessed during the launch of this cohort study at T2.
Measures
We investigated the mental state of the participants with two
self-administered questionnaires. EPDS is a well-known screening
tool for depression in women during pregnancy and postpartum.
The TCI is used to assess four dimensions of temperament
including HA and three dimensions of character. We examined
EPDS and TCI scores during early pregnancy (that is, before 25
weeks at T1) and at 1 month postpartum (at T2).
The Edinburgh Postnatal Depression Scale. We
evaluated the depressive state (measured by EPDS) of
participants during the period right after childbirth using the
EPDS [21,22]. The EPDS is a self-reported questionnaire that
includes 10 items designed to screen for postpartum depression in
community samples. Each item is scored on a four-point Likert
scale (from 0 to 3), with scores ranging from 0 to 30. This scale
focuses on the cognitive and affective features of depression, rather
than on somatic symptoms. Its sensitivity and specificity in a
Japanese community sample were 75% and 93%, respectively,
using a cut-off point of 8/9 [23]. The 8/9 cut-off point to screen
for depressive women was also used in the present analyses. This
questionnaire has also been validated as a screening instrument for
use throughout pregnancy and is comparable to other screening
scales for depression for use in community samples. When used in
community settings, this scale is referred to as the Edinburgh
Depression Scale [24].
The Temperament and Character Inventory. Personality
traits including HA were measured with the TCI. The TCI is a
self-reported questionnaire that includes 125 items that tap into
four dimensions of temperament (novelty seeking, HA, reward
dependence, and persistence) and three dimensions of character
(self-directedness, cooperativeness, and self-transcendence). HA
was originally assumed to be influenced by the serotonergic system
[25]. We used the Japanese version of the TCI-125, which
includes 125 questions including 20 items pertaining to HA [26].
HA scores ranged from 0 to 20 and consisted of the following four
subscales, anticipatory worry (0–5), fear of uncertainty (0–5),
shyness with strangers (0–5), and fatigability and asthenia (0–5).
Statistical analysis
Analysis of variance (ANOVA) was used to test the mean
differences within the four groups divided by EPDS (Table 1). The
student t-test was used to compare HA scores between the ND and
PD groups at T1 (Table 2). Paired t-test was used to calculate
changes in EPDS scores and HA scores between T1 and T2 in the
ND and PD group (Table 3 and 4). Cohen’s d was used to show
the differences in HA and EPDS from T1 to T2 as effect size in the
ND and PD group (Table 3 and 4). Cohen’s d was calculated from
means, standard deviations and sample size in two groups.
Correlations between EPDS and HA scores at T1, T2, and
Table 4. HA scores in the ND and PD groups.
T1 T2 p-value
a
Cohen’s d
n mean SD mean SD
ND group 81 10.4 4.3 10.1 3.8 0.27 20.07
PD group 18 11.1 5.0 12.3 4.2 0.048 0.26
All 99 10.6 4.4 10.5 3.9
HA: harm avoidance.
T1: early pregnancy (before 25 weeks).
T2: postpartum (1 month).
a
: Paired t-test in HA scores between T1 and T2 in the ND and PD groups.
doi:10.1371/journal.pone.0034725.t004
Table 5. Correlations between HA and EPDS score changes
from T1 to T2 in the ND and PD groups.
ND and PD groups (n = 99) r p-value
HA total 0.31 0.002
HA subscale Anticipatory worry 0.16 0.12
Fear of uncertainty 0.17 0.10
Shyness with strangers 0.13 0.21
Fatigability and asthenia 0.29 0.003
r: Pearson’s r.
doi:10.1371/journal.pone.0034725.t005
Harm Avoidance and Postpartum Depressive State
PLoS ONE | www.plosone.org 4 April 2012 | Volume 7 | Issue 4 | e34725
changes in EPDS score and HA total score/subscores from T1 to
T2 were evaluated based on Pearson’s coefficients (r) within the
ND+PD group (Table 5). Significance levels were set at p,0.05.
All p-values were two-tailed p-values. IBM SPSS Statistics Version
19 (IBM Japan, Tokyo) was used for all analyses.
Supporting Information
Figure S1 Changes in EPDS score in ND and PD group.
(TIF)
Figure S2 Changes in HA score in ND and PD group.
(TIF)
Figure S3 HA and EPDS score changes from T1 to T2 in
the ND and PD groups.
(TIF)
Acknowledgments
We thank the staff at Nagoya Teishin Hospital and Kaseki Hospital. We
also thank our group members: M. Banno, H. Hirose, M. Tomida, S.
Hamada, Y. Wakui, and A. Fukuoka.
Author Contributions
Conceived and designed the experiments: KF TK TO SM SG AK T.
Masuda NO. Analyzed the data: KF TK TO BA NO. Contributed
reagents/materials/analysis tools: KF NH TS YN AT NI HO HU NB T.
Morita SG AK T. Masuda NO. Wrote the paper: KF TK TO BA.
References
1. Klein DN, Kotov R, Bufferd SJ (2011) Personality and depression: explanatory
models and review of the evidence. Annu Rev Clin Psychol 7: 269–295.
2. Riso LP, Miyatake RK, Thase ME (2002) The searc h for determinants of
chronic depression: a review of six factors. J Affect Disord 70: 103–115.
3. Mulder RT (2002) Personality pathology and treatment outcome in major
depression: a review. Am J Psychiatry 159: 359–371.
4. Kendler KS, Kuhn J, Prescott CA (2004) The interrelationship of neuroticism,
sex, and stressful life events in the prediction of episodes of major depression.
Am J Psychiatry 161: 631–636.
5. Brown SL, Svrakic DM, Przybeck TR, Cloninger CR (1992) The relationship of
personality to mood and anxiety states: a dimensional approach. J Psychiatr Res
26: 197–211.
6. Joffe RT, Bagby RM, Levitt AJ, Regan JJ, Parker JD (1993) The Tridimensi onal
Personality Questionnaire in major depression. Am J Psychiatry 150: 959–960.
7. Hirano S, Sato T, Narita T, Kusunoki K, Ozaki N, et al. (2002) Evaluating the
state dependency of the Temperament and Character Inventory dimensions in
patients with major depression: a methodological contribution. J Affect Disord
69: 31–38.
8. Andriola E, Di Trani M, Grimaldi A, Donfrancesco R (2011) The Relationship
between Personality and Depression in Expectant Parents. Depression Research
and Treatmentdoi: 10.1155/2011/356428.
9. Cloninger CR, Svrakic DM, Przybeck TR (1993) A psychobiological model of
temperament and character. Arch Gen Psychiatry 50: 975–990.
10. Ishikawa N, Goto S, Murase S, Kanai A, Masuda T, et al. (2011) Prospective
study of maternal dep ressive sy mptomatology among Japanese women.
J Psychosom Res 71: 264–269.
11. Brockington I (2004) Postpartum psychiatric disorders. Lancet 363: 303–310.
12. Kumar R, Robson KM (1984) A prospective study of emotional disorders in
childbearing women. Br J Psychiatry 144: 35–47.
13. Evans J, Heron J, Francomb H, Oke S, Golding J (2001) Cohort study of
depressed mood during pregnancy and after childbirth. BMJ 323: 257–260.
14. Beck CT (2001) Predictors of postpartum depression: an update. Nurs Res 50:
275–285.
15. Yoshida K, Marks MN, Kibe N, Kumar R, Nakano H, et al. (1997) Postnatal
depression in Japanese women who have given birth in England. J Affect Disord
43: 69–77.
16. Kumar R (1994) Postnatal mental illness: a transcultural perspective. Soc
Psychiatry Psychiatr Epidemiol 29: 250–264.
17. O’Hara MW, Zekosk i EM, Philipps LH, Wright EJ (1990) Controlled
prospective study of postpartum mood disorders: comparison of childbearing
and nonchildbearing women. J Abnorm Psychol 99: 3–15.
18. Lee KA, Zaffke ME (1999) Longitudinal changes in fatigue and energy during
pregnancy and the postpartum period. J Obstet Gynecol Neonatal Nurs 28:
183–191.
19. Sharma V, Burt VK, Ritchie HL (2009) Bipolar II postpartum depression:
Detection, diagnosis, and treatment. Am J Psychiatry 166: 1217–1221.
20. Sharma V, Khan M, Corpse C, Sharma P (2008) Missed bipolarity and
psychiatric comorbidity in women with postpartum depression. Bipolar Disord
10: 742–747.
21. Cox JL, Holden JM, Sagovsky R (1987) Detection of postnatal depression.
Development of the 10-item Edinburgh Postnatal Depression Scale.
Br J Psychiatry 150: 782–786.
22. Wisner KL, Parry BL, Piontek CM (2002) Clinical practice. Postpartum
depression. N Engl J Med 347: 194–199.
23. Okano TMM, Masuji F, Tamaki R, Nomura J, Miyaoko H (1996) Validation
and reliability of Japanese version of the EPDS. Arch Psychiatr Diag Clin
Evaluat. pp 525–533.
24. Cox JL, Chapman G, Murray D, Jones P (1996) Validation of the Edinburgh
Postnatal Depression Scale (EPDS) in non-postnatal women. J Affect Disord 39:
185–189.
25. Cloni nger CR (1987) A systematic method for clinical description and
classification of personality variants. A proposal. Arch Gen Psychiatry 44:
573–588.
26. Kijima N, Saito R, Takeuchi M, Yoshino I, Ono Y, et al. (1996) Cloninger’s
seven-factor model of temperament and character and Japanese version of
Temperament and Charactor Inventory (TCI). Kikan Seishinka Shindangaku 7:
379–399.
Harm Avoidance and Postpartum Depressive State
PLoS ONE | www.plosone.org 5 April 2012 | Volume 7 | Issue 4 | e34725
