Journal of Affectiue Disorders, 26 ( 1992) 23 l-240 0 1992 Elsevier Science Publishers B.V. All rights reserved 01650327/92/$05.00
231
ges in early p Fabienne Bonnin Laboratoire de Psychophysiologie, Facultk des Sciences et Techniques, Besanqon, France (Received 26 March 1992) (Revision received 3 August 1992) (Accepted 19 August 1992)
Summary Cortisol levels in saliva were measured in 22 women, daily from the 2nd to 7th day after they had given birth and in 7 control women for 6 consecutive days. During the same period the mothers filled out a mood self-rating scale. The cortisol levels of the mothers were higher than those of the controls and progressively decreased after birth except for the 4th day post-partum when there was an increase. Five mothers had post-parttim blues, but their cortisol levels were.not different from those of other mothers. However, there was a significant correlation between cortisol level and the mood of mothers who bottle fed their babies.
Key words: Post-partum;
Mother’s mood; Cortisol
Maternity is accompanied by biological modifications, changes in the body, emotional readjustments and variations in the psycho-social environment of the future mother. Then the period following birth is characterized by various mental disorders. The frequency of post-partum depressive states is well-known. More generally, most of the nosological descriptions which recognize the specificity of the post-partum depressive states,
Correspondence to: F. Bonnin, Laboratoire de Psychophysiologie, Fact&C des Sciences et Techniques, Route de Gray, 25030 Besanqon, France.
distinguish three types of mental disorders which can occur after birth: 1. Post-partum blues 2. Post-partum depression 3. Puerperal psychosis Post-par-turn blues include, with differing degrees of intensity, mood and sleep disturbances, anxiety, emotional !ability, fatigue and self-dislike, with sometimes certain cognitive disturbances su:h as poor concentration and forgetfulness. Post-partum blues are considered to be a frequent transitory and benign syndrome, affecting between 30 and 80% of women after childbirth. These blues only last a few days and generally occur around the 4th day post-partum Wendell et al., 1984) and in the majority of cases disappear
‘37
spontaneously. If the dep.ressive state is particulady intense and lasts more than one week. it cgn be the onset of post-partum depression (Pitt, 1973; Brockinton and Kumar. 1982; Cox et al, 1982; Lemperiere, 1983; Kendeil et al., 1984; Kennerley and Gath, 1986; Steiner, 1990). Many etiologicai theories suggest a biological origin for these post-partum blues. The major argument is that the depressive state coincides with a decline in estrogens and progesterone (Nott et al., 1976; Feksi et al., 19841, a disdppearance of foctoplacental hormones (Tonge, 1986) and an increase in prolactin secretion (Dalton. 1980 Steiner, 1986). The second argument for a biological origin is the observation that women who suffer from post-partum blues also suffer from premenstrual restlessness and depression. These signs are considered to indicate psychological vulnerability to hormonal variations (Lemperiere, 1983; Hopkins et al., 1984). Pitt (1973) thought that the presence of feelings of confusion as a symptom of post-partum blues proved that these blues were organically determined. Cortisol is a hormone whose hypersecretion characterizes certain types of depression (Carpenter and Bunney, 1971; Stein et al., 1976; Prange et al., 1977; Lemperiere, 1983; Nemeroff, 1989). As corticosteroids, including cortisol, are involved in stress and defence situations as Selye (1956) has demonstrated, it ran be thought that they also can play a role during pregnancy and delivery. Plasma cortisol levels increase during pregnancy, reach a peak during delivery and then progressively decrease during the days following delivery (Jolivet et al., 1974; Gelder, 1978; Stave, 1978; Batra and Grundsell, 1978; Handley et al., 1980; Smith, 1986). Kuevi et al. (1983) and Steiner et al. (1986) did not find any correlation between the plasma cortisol levels and the existence of post-partum blues. According to Feksi et al. (1984), the cortisol levels in saliva of mothers who were not suffering from postpartum blues were characterized by a secretory peak on the third day after delivery. Whereas, for mothers with post-partum blues, the cortisol levels were at their maximum on the first day post-partum.
Handley et al. (1980) found a correlation between a depressive mood and high levels of plasma cortisol during the 38th week of pregnancy and the 5th day after delivery, but only for women who gave birth to their child during a definite period of the year, between January and April. Smith (1986) observed the same reaction to the ‘dcxamethasone suppression test’ :n pregnant women and women during the post-partum period as for people suffering %m depression. The aim of this experiment was to find the correlations that could exist between the variations in cortisol levels in saliva and mothers’ mood during the first days after delivery and to determine the daily evolution of these two parameters. The daily observation of hcrmonal or mental changes required the use of techniques which could be applied during several consecutive days. This study investigates these techniques and compares the cortisoI levels in mothers and in a control group. To be able to understand correlations between a. biological aspect (cortisol) and a psychological aspect (mood), possible factors influencing the variations in cortisol level and mothers’ moods were investigated. ethod Salit~acortisol assays
Saliva specimens were collected each morning between 8:00 and 9:00 a.m. from the 2nd to the 7th day after delivery. As cortisol has a circadian rhythm (Touitou et al., 1983) it was important for the specimens to be taken at the same time each day, so that they could be compared from one day to the next. The mothers were asked to rince their mouth with clear water for about IO min before giving the sample. They were then asked to spit saliva into a test tube until there was 1 millimeter of saliva in the tube. The samples were then deep frozen for later assay. Salivary cortisol assay has the advantage of being non-invasive, stress-free and less aggressive than a blocd test. This test provides the free
233
salivary cortiso! level and is a true representation of plasma free cortisol whatever the time of day the spe:imeus were collected Wad-Fahmy et al., 1982; Peters et al., 1982; Alen et al., 1973; Fiet et al., 1981). The assays were made according to the direct immunoassay method used for plasma and urinary assays (Peters et al., 1982; Schoneshofer et al., 1980).
ing from the 2nd to 7th day after tbz birth of her child. In accordance with Von 3%-ssen et al. (I974), each score can be put inta one of the folIowing five categories: Mood le~l: Euphoric (I), Relaxed 421, Anxious (3, SEig ately depressed (41, CIearly or etiremely depressed (5). Each morning a mood level rating from 1 to 5 was given to each mot Population
The study of transitory post-partum blues requires a standardized mood measuring instrument which is adapted to the experimental situation. The scale must be easy and fast to use so as not to overburden the mothers with tests. The test must also be able to be used day after day to show the rapid variations in mood (Kennerley and Gath, 1986). The Zerssen self-rating scale which requires ten minutes to complete, was used. This scale has the advantage of being sensitive to rapid mood changes and of having been validated on both depressed and control subjects. It has been correlated with biological data and has been significantly correlated with other scales such as that of Beck and that of Zung Won Zerssen et al., 1974; Heiman et al., 1975). According to Bobon (1987), the Zerssen scale is the only self-evaluating mood scale that has been extensively validated in the French language. There are two versions lBfS and BfS’) which can be used alternatively. However, as the equivalence was not complete (Bobon, 1987) it was decided to use only one version (BfS), so that comparisons could be made. The scale is made up of a list of 28 pairs of antonyms. The mothers were asked to tick the adjective which best described what they felt at that particular time: ‘more one’ or ‘the other’ or ‘neither one nor the other’. An overall score was obtained by adding the results: 2 points for a negative adjective, 0 points for a positive adjective and 1 point for a ‘neither one nor the other’ response. The score became a quantitative evaluation of the mothers’ depressive mood. Each mother filled out the rating each morn-
This experiment was carried out \%ith 22 mothers who accepted to take part in the study. All mothers had a normal delivery without general anesthesia or cesarian. All mothers .iad a normal pregnancy without any serious bic&gicai or psychological complications. Al1 infants were fullterm and were clinically normal (Apgar score of 10 at 1 and 5 min). No infar : had a birth weight of less than 2750 g. The control population, whose cartis levels were compared with those of the nothers, was made up of 7 primiparas or multiparas whose age could be compared with that of the mothers (between 20 and 39 years of age) and who were observed outside a post-partum or post hospitalisation period. The saliva samples were taken between 8:00 and 9:00 AM on 6 consecutive days. These samples were then stored and assayed under the same conditions as those of the mothers monitored at the clinic after their delivery. A questionnaire was given to the mothers, to take individual informations like the existence of premenstrual syndrome (nervosity, irritability), and special illness during pregnancy. The medical file of the mothers has been read, with the gynaecologist’s permission. The sleepless night was noted every day before the tests. All the newborns stay overnight in the nursery and are bottle-fed between 10.00 p.m. and 6.00 a.m. Statistical treatment of data The data obtained were statistically treated. The normality of the data was verified with the Lilliefors test. The comparison between several means was obtained with the one-way analysis of variance for repeated measures (the measures
MEW
LEVEL 38
been demonstrated by Handley et al. (1980) and Kuevi et al. (1983). Our results show the particular nature of the 4th day when there was a higher cortisol level than either the previous or following day, whereas in general the levels progressively decreased from the 2nd to the 7th day post-partum.
OF CORTISOL
T
Inji’uenceof indiuidual variableson cortiso! level z
3
4 POSTPkRTUM
5
6
7
DAYS
Fig. 1. Evolution from the 2nd to the 7th day post-partum of the mean level (and standard error) of free salivary cortisol ir. mothers (N = 22) expressed in nmol/l.
have been repeated each day during 6 days). The comparison of two means was made with the Student’s t-test. The a posteriori comparisons between related samples were made with the Scheffe test and the independent samples with the Duncan test. The Spearman correlation coefficient was used for the CL ltions.
Results Evolution of saliclarycortisol during the first week post-~a~t~~~~ Fig. 1 shows the evolution of the mean of free salivary cortisol of 22 mothers, from the 2nd to the 7th day after delivery. The mean levels were between 14.05 nmol/l, and 25.95 nmol/l with the mean at 21.59 nmol/l and a standard deviation of 9.6. The sahvary cortisol levels were higher than the mean on the 2nd, 3nd and 4th days postpartum. From the 5th to the 7th days the mean cortisol levels progressively decreased. An analysis of variance shows that there was a significant difference between days (F = 0.549 P = 0.001) and particularly between the 7th and 2nd days and between the 7th and 4th days (Scheffe test). The overall reduction in the cortisol levels during the days following delivery has already
Variables concerning the period before pregnancy and pregnancy itself Premenstrual syndrome. The mothers who regularly had premenstrual syndromes of the anxiety type (N = S! had a significantly higher level of cortisol than the other mothers (t = 3.35 P = 0.001). Weightgain during pregnancy. The cortisol level of mothers who gained more than 15 kg (N = 8) during pregnancy was higher than those who did not gain as much (F = 0.365 P = 0.01). Professionalactivity. The cortisol level of mothers who had a professional activity during pregnancy (k = 11) was higher than those who did not (t = 2.54 P = 0.01). Hospitaiisationduring pregnancy. Mothers who were hospitalized during pregnancy had higher cortisol levels than those who were not (t = 2.57 P = 0.02). Health problems during pregnancy. Mothers who had somatic problems during preg nancy (nausea, persistant pain, etc) had higher cortisol levels than those who did not (t = 5.52 P = 0.02). Variablesconcerning post-par&m period New-bornfeeding method. The mothers who breast fed their babies (N = 14) had overall significantly higher levels of cortisol than mothers who bottle fed their infants (N = 8) (t = 2.45 P = 0.01). Th e mean for mothers who breast fed their babies was 22.93 nmol/l (SD =
235
10.91) and that for mothers who bottle fed their infants was 19.25 nmol/l (SD = 6.17). Jolivet et al. (1974) did not show the difference in the plasma cortisol levels in relation to feeding method during the days following delivery. Fig. 2 shows that the mothers who breast fed their babies had higher cortisol levels frout the 2nd to the 6th days with a maximum on the 4th day. For mothers who bottle fed their infants the maximum was observed on the 2nd day with a plateau until the 6th day. There was a marked decrease on the 7th day in both groups of mothers. There were significant differences for mothers who breast fed their babies between the 7th and 2nd days, the 7th and 3nd days, the 7th and 4th days. For mothers who bottle fed their babies the only significant difference was between the 7th and 2nd days post-partum (Scheffe test).
Insomnia. Cortisol levels tended to be higher after a sleepless night, whatever the time of night when the mother was unable to sleep (t = 1.92 P = 0.06).
Parity. Primiparas (IV = 8) had a higher level of cortisol than multiparas (1 = 4.86 P = 0.0001). The cortisol level of mothers aged less than 25 years was higher than that of mothers older than 25 years (F = 7.4 P = 0.01). However, it must be noted that the majority of primiparas were under 25 years of age. Jolivet et al. (1974) have demonstrated the importance of parity.
Comparison with control pop&ation
MEAN
LEVEL
2
OF CORTISOL
3
4 POSTPARTUM
6
s
7
DAYS
Fig. 2. Evolution from the 2nd to 7th day post-partum of the mean level (and standard error) of free salivary cortisol in mothers expressed in nmol/l in relation to newborn feeding method (breast feeding N = 14, bottle feeding N-T 8).
Delivery time. Mothers who gave birth between 6pm and midnight had higher cortisol levels than those who gave birth during the day time (F = 7.2 P = 0.0001). The other variables that were taken into account did not have a significant influence on the mothers’ cortisol levels. These non-significant variables were: age, smoker or non-smoker, attended or not classes for mothers-to-be, had anesthesia during delivery, delivery duration, sex of baby, wanted or not wanted pregnancy, difference between due time and actual delivery time, delivery season, duration of mother-baby contact time immediately after delivery.
The mean cortisol level of the control population was 14.33 nmoI/l (SD 5.91). The evolution from one day to the next during the six days of the experiment is presented in Fig. 3. There is no significant difference between the days (F = 0.56 P = 0.72). The levels obtained in our experiment do not differ from those obtained by Fiet et al. (1981) who observed a mean level of salivary cortisol of 15.47 +_0.6 nmol/l in the control population. However, our levels are significantly lower than those obtained from mothers during the week following delivery (4.33 as against 21.59) (t = 4.61 P = 0.0001). This would confirm the existence of higher cortisol levels during the clays following delivery. The 7th day after delivery, the mean level of salivary cortisol could be compared with that of our control group. Mothers’ mood Fig. 4 shows the evolution from the 2nd to the 7th day after delivery of the mean mood ratings of mothers according to the Zerssen Scale. The overall average rating was 1.85 (SD 1.04) which corresponds to an overall relaxed mood level.
736 MEAN
10
LEVEL
MEAN
OFCORTISOL
_ 1
2
3
4
5
6
2
3
4 POSTPARTUM
DAYS
Fig. 3. Evolution during 6 days of the mean level (and standard error) of free salivary cortisol expressed in nmol/l for the control population (N = 7).
However, there was a higher rating on the 3nd day post-partum than on the other days, indicating that there were more anxious or depressed mothers on this day, because with the Zerssen scale the higher the score, the more the mood is depressed. The mothers’ mood rating slightly decreased over the following days, but the variations were not significant (F = 0.96 P = 0.44). There was a significant difference between mothers who breast fed their babies and those who bottle fed their infants. Mothers who breast fed their babies were more depressed (mean 2.02 as against 1.57, t = 3.27 P = 0.001). Fig. 5 shows the evolution of the mothers’ mood in relation to feeding method. There is a difference every day except the 4th day post-partum. others who were hospitalized during pregnancy tended to be more depressed than those MEAN 2.5
5
6
7
DAYS
Fig. 5. Evolution from the 2nd to the 7th day post-partum of the mood ratings by mothers on the Zerssen Scale (mean and standard error) in relation to newborn feeding method (breast feeding N = 14, bottle feeding N = 8).
who were not (t = 4.11 P= 0.001). The other parameters noted above did not have a statistically significant influence on the mothers’ mood. When a finer analysis is made of the evolution of each of the 22 mothers’ m _ad, there would appear to be three distinct groups: 1. Mothers whose score was never over 2 during the week after birth. These mothers were considered to be relaxed. 2. Mothers whose score was 3 during at least cne day, but did not have a score over 3. These mothers were considered to be anxious. 3. Mothers whose score was 4 or 5 during at least one day. This score characterizes a moderately OS’extremely depressed state. These mothers were considered to be suffering from postpartum blues. In our population of 22 mothers, 14 were relaxed, 3 were anxious and 5 were depressed. This latter figure indicates that approximately 22% of the mothers suffered from transitory post-partum depression. The days when the mothers were depressed were day 3, and to a lesser extend, day 4 post-partum. CortisolLevelsand mothers’ mood
2
3
4 POSTPARTUM
S
6
7
DAYS
Fig. 4. Evolution from the 2nd to the 7th day post-partum of the mood scores by mothers on the Zerssen Scale (mean and standard error) (N = 22).
The above results indicate that the mothers who breast fed their babies had higher cortisol levels than the other mothers and tended to be more depressed.
237
There is a tendency towards a statistical correlation between the cortisol levels and mothers’ mood on the 3nd (r = 0.27 P = 0.1) and the 5th day post-partum (r = 0.28 P = 0.1). This correlation was positive and indicates that the higher the cortisol level, the more the mood rating is of a depressive type. However, there is no correlation on the other days (2nd day Y= 0 P= 0.3, 4th day r =0.12 P = 0.28, 6th day r = 0.12 P = 0.28, 7th day r = 0.18 P = 0.22). When the baby was bottle fed the mothers’ mood rating and their cortisol level are significantly correlated on the 3nd day (r = 0.69 P = 0.021, the 7th day (r = 0.64 P = 0.051, and a tendency appears on the 5th day (r = 0.53 P = 0.08). No one correlation appears when the baby was breast fed. There was no significant difference between the cortisol levels of the three groups of mothers that were made according to their mood (F = 0.7
P = 0.49). However, all three groups show an increase in cortisol levels on the 4th day post-partum.
The major interest of this study is that daily measurements were taken when the mothers were in a stable environment; maternity hospital. This daily monitoring is only possible when stress-free techniques are used, this is the case when steroid hormone assays are made from saliva. The mood self-rating scale that was used can be administered repeatedly within short periods of time. These techniques can be used with a larger population. It would be of interest to take measurements at different times of the day, as little is known about the evolution of circadian mood rhythms during the days after delivery. The Zerssen Mood Scale does not provide a detailed analysis of the different aspects of postpartum psychological disorders, but the results of this study would indicate that it can be a starting and reference point which could be completed by the use of other diagnostic instruments (Bonnin, in press). Specific instruments such as the Edinburgh Postnatal Depression Scale (Cox, 1986;
Harris et al., 1989) have not yet been translated and adapted to the French language. The progressive decrease of cortisol levels in mothers between the 2nd and 7th days postpartum follow the progressive cortisol increase that has been observed during pregnancy and that reaches a peak at delivery (Jolivet et al., 1974; Batra and Grundsell, 1978; Handley et al., 1980; Kuevi et al., 1983). The increase in corticosteroid secretion is probably associated with the physical and psychological stress of delivery, but it also enables the mobilisation of muscular energy required for labour. The decrease in cortisol levels during the week that followed delivery was not linear as there was a transitory increase on the 4th day. It must be noted that this increase occurred the day after a higher frequency of depressive states in the mothers. The cortisol levels in mothers are influenced by a number of variables. Some of them highlight the existence of physical and psychological difficulties during pregnancy (weight gain, hospitalization, carrying on a professional activity during pregnancy, health problems during pregnancy). Women who were hospitalized during pregnancy then had the risk of giving premature birth. Our findings show that these risks had psychophysiological effects which could be observed after delivery. These mothers not only had higher cortisol levels than other mothers, but they were also more depressed. The influence of the delivery time would suggest that the modifications in the cortisol circadian secretory rhythms are linked to an absence of sleep during a part of the night. This can be associated with the results concerning the influence of insomnia. Our findings also highlight the influence of the feeding method variable. Mothers who breast fed their babies had a more depressive mood and higher cortisol levels than the other mothers. The major differences between mothers who breast or bottle feed their babies is the secretion of prolactin. In the case of mothers who bottle feed their babies, this secretion is inhibited by a drug administered on the first day post-partum. Certain authors have observed a correlation between
the level of prolactin and depressive moods, but it must be noted that this correlation has been put into question (Zarifian and Loo, 1982). Our findings show that, when proiactin is inhibited, there is a significant correlation between mothers’ mood and their cortisol level. This study confirms the existence of psychophysiological changes on the 3nd and 4th days post-partum which can have a pathological aspect for approximately 22% of the mothers. However, no one-to-one relation between mothers’ mood and their cortisol levels was observed in our population. There was a correlation between the two parameters in the case of mothers who bottle fed their baby. The increase in cortisol level on the 4th day was observed in both the mothers who were suffering from baby blues and those who were not. It can be thought thal research on the etiology of post-partum depression needs to include individual variables which could modify the biological parameters being studied. Some of the contradictions found in the literature dealing with the etiology of post-partum disorders couid be due to the absence of an analysis of these variables. Our results demonstrate the complexity of the phenomena observed and the difficulty of isolating all the aspects of the etiology of psychological post-partum disorders. However, the realisation and knowledge of factors predisposing mothers to or correlating with psychological post-partum isorders could help to prevent these disorder< from becoming the onset point for more severe post-partum depression. The question is of importance when the consequences of post-partum disorders on the genesis of mother-infant attachment and the psychological development of the child a~ taken into account. References Batra S. and Grundseii,H. (1978) Studr-s on certain aspects of progestenme and cortisoi dynamic, before, during and after iabour. Ciin. Endocrinol. 8, 403~400. Bonnin, F. (1992) Ddtection des itat\ dipressifs du postpartum avec I’Cchelle d’auto-ivaluation de Zerssen, L’EncCphale (in press). Bonnin, F., Taillard, C. and Montagner, H. (lY901 Variations
quotidiennes et saisonnikres de la sensibiliti oifactive des m&es aprCs I’accouchement et de ieurs capacites de discrimination vis-g-vis de i’odeur corporelle de ieuir nouveau-&. Don&es priiiminaires. J. Gyn&oi. Obstttr. Biol Repro. 19, 165-170. Bobon, D. (1987) Psychopathologic quantitative et mesure du changement. in: Mendlewicz. J. (Ed.), Manuel de psychiatrie, Masson, Paris. 11-20. Brockington, I.F., Kumar, R. (1982) Motherhood and mental illness, Academic Press, New-York. Carpenter, W.T. and Bunney, W.E. (19711) Adrenal cortical activity in depressive illness. Am. J. Psychiatry, 128, 31-40. Cox, J.L., Connor, Y. and Kendeii, E. (1982) Prospective study of the psychiatric disorders of childbirth. Br. J. Psychiatry, 140, 1I l- 117. Dalton. K. (1980) Depression after childbirth, Oxford University Press. Feksi. A., Harris. B., Walker. R.F., Riad-Fahmy, D. and Newcombe. R.G. (1984) Maternity blues and hormone levels in saliva. J. Affect. Dis. 6. 351-355. Fiet. J.. Passa, P., Guechot, J.. Gourmei. B., Viiiette, J.M. and Cathelineau, G. (1981) IntCrit du dosage du cortisoi dans la saiive. Nouvelie Presse Mid. 32, 2664. Gaien, F.X., Pesquies, P., Menard, J., Corvoi. P. (1073) Excretion des St&ides parotidiens en relation avec les variations de la cortisoiimie. Annie Bioi. Clin. 31, 459-465. Geider, M. (lY78) Hormones and post-partum depression. In: M. Sandier (Ed.), Mental illness in pregnancy and the puerperium. Oxford University Press pp. 80-90. Handiey, S.L., Dun, T.L.. Waldron, W. and Baker, J.M. (1980) Tryptophan. cortisoi and puerperal mood. Br. J. Psychiatry, 136, 498-508. Heiman. H.. Bobon-Schrod, H., Schmocker, A.M. and Bobon, D.P. (1975) Auto-ivaluation de i’humeur par une liste d’adjectifs, la “Befindiichkeits-Skaia” (BS) de Zerssen, L’enciphaie, 1, 165-183. Hopkins, J., Marcus, M. and Campbell, S.B. (1984) Postpartum depression: a critical review. Psycholog. Bull. J5, 498-5 15. Joiivet, A., Blanchier. H., Gautray. P. and Dhem, N. (1974) Blood cortisoi variations during late pregnancy and labor. Am. J. Obst. Gynecol. 119, 775-782. Kendeli, R.E., Ckenzie, W.E., West, C., McGuire, R.J. and Cox, J.L. (1083) Day-to-
231
ges in early p Fabienne Bonnin Laboratoire de Psychophysiologie, Facultk des Sciences et Techniques, Besanqon, France (Received 26 March 1992) (Revision received 3 August 1992) (Accepted 19 August 1992)
Summary Cortisol levels in saliva were measured in 22 women, daily from the 2nd to 7th day after they had given birth and in 7 control women for 6 consecutive days. During the same period the mothers filled out a mood self-rating scale. The cortisol levels of the mothers were higher than those of the controls and progressively decreased after birth except for the 4th day post-partum when there was an increase. Five mothers had post-parttim blues, but their cortisol levels were.not different from those of other mothers. However, there was a significant correlation between cortisol level and the mood of mothers who bottle fed their babies.
Key words: Post-partum;
Mother’s mood; Cortisol
Maternity is accompanied by biological modifications, changes in the body, emotional readjustments and variations in the psycho-social environment of the future mother. Then the period following birth is characterized by various mental disorders. The frequency of post-partum depressive states is well-known. More generally, most of the nosological descriptions which recognize the specificity of the post-partum depressive states,
Correspondence to: F. Bonnin, Laboratoire de Psychophysiologie, Fact&C des Sciences et Techniques, Route de Gray, 25030 Besanqon, France.
distinguish three types of mental disorders which can occur after birth: 1. Post-partum blues 2. Post-partum depression 3. Puerperal psychosis Post-par-turn blues include, with differing degrees of intensity, mood and sleep disturbances, anxiety, emotional !ability, fatigue and self-dislike, with sometimes certain cognitive disturbances su:h as poor concentration and forgetfulness. Post-partum blues are considered to be a frequent transitory and benign syndrome, affecting between 30 and 80% of women after childbirth. These blues only last a few days and generally occur around the 4th day post-partum Wendell et al., 1984) and in the majority of cases disappear
‘37
spontaneously. If the dep.ressive state is particulady intense and lasts more than one week. it cgn be the onset of post-partum depression (Pitt, 1973; Brockinton and Kumar. 1982; Cox et al, 1982; Lemperiere, 1983; Kendeil et al., 1984; Kennerley and Gath, 1986; Steiner, 1990). Many etiologicai theories suggest a biological origin for these post-partum blues. The major argument is that the depressive state coincides with a decline in estrogens and progesterone (Nott et al., 1976; Feksi et al., 19841, a disdppearance of foctoplacental hormones (Tonge, 1986) and an increase in prolactin secretion (Dalton. 1980 Steiner, 1986). The second argument for a biological origin is the observation that women who suffer from post-partum blues also suffer from premenstrual restlessness and depression. These signs are considered to indicate psychological vulnerability to hormonal variations (Lemperiere, 1983; Hopkins et al., 1984). Pitt (1973) thought that the presence of feelings of confusion as a symptom of post-partum blues proved that these blues were organically determined. Cortisol is a hormone whose hypersecretion characterizes certain types of depression (Carpenter and Bunney, 1971; Stein et al., 1976; Prange et al., 1977; Lemperiere, 1983; Nemeroff, 1989). As corticosteroids, including cortisol, are involved in stress and defence situations as Selye (1956) has demonstrated, it ran be thought that they also can play a role during pregnancy and delivery. Plasma cortisol levels increase during pregnancy, reach a peak during delivery and then progressively decrease during the days following delivery (Jolivet et al., 1974; Gelder, 1978; Stave, 1978; Batra and Grundsell, 1978; Handley et al., 1980; Smith, 1986). Kuevi et al. (1983) and Steiner et al. (1986) did not find any correlation between the plasma cortisol levels and the existence of post-partum blues. According to Feksi et al. (1984), the cortisol levels in saliva of mothers who were not suffering from postpartum blues were characterized by a secretory peak on the third day after delivery. Whereas, for mothers with post-partum blues, the cortisol levels were at their maximum on the first day post-partum.
Handley et al. (1980) found a correlation between a depressive mood and high levels of plasma cortisol during the 38th week of pregnancy and the 5th day after delivery, but only for women who gave birth to their child during a definite period of the year, between January and April. Smith (1986) observed the same reaction to the ‘dcxamethasone suppression test’ :n pregnant women and women during the post-partum period as for people suffering %m depression. The aim of this experiment was to find the correlations that could exist between the variations in cortisol levels in saliva and mothers’ mood during the first days after delivery and to determine the daily evolution of these two parameters. The daily observation of hcrmonal or mental changes required the use of techniques which could be applied during several consecutive days. This study investigates these techniques and compares the cortisoI levels in mothers and in a control group. To be able to understand correlations between a. biological aspect (cortisol) and a psychological aspect (mood), possible factors influencing the variations in cortisol level and mothers’ moods were investigated. ethod Salit~acortisol assays
Saliva specimens were collected each morning between 8:00 and 9:00 a.m. from the 2nd to the 7th day after delivery. As cortisol has a circadian rhythm (Touitou et al., 1983) it was important for the specimens to be taken at the same time each day, so that they could be compared from one day to the next. The mothers were asked to rince their mouth with clear water for about IO min before giving the sample. They were then asked to spit saliva into a test tube until there was 1 millimeter of saliva in the tube. The samples were then deep frozen for later assay. Salivary cortisol assay has the advantage of being non-invasive, stress-free and less aggressive than a blocd test. This test provides the free
233
salivary cortiso! level and is a true representation of plasma free cortisol whatever the time of day the spe:imeus were collected Wad-Fahmy et al., 1982; Peters et al., 1982; Alen et al., 1973; Fiet et al., 1981). The assays were made according to the direct immunoassay method used for plasma and urinary assays (Peters et al., 1982; Schoneshofer et al., 1980).
ing from the 2nd to 7th day after tbz birth of her child. In accordance with Von 3%-ssen et al. (I974), each score can be put inta one of the folIowing five categories: Mood le~l: Euphoric (I), Relaxed 421, Anxious (3, SEig ately depressed (41, CIearly or etiremely depressed (5). Each morning a mood level rating from 1 to 5 was given to each mot Population
The study of transitory post-partum blues requires a standardized mood measuring instrument which is adapted to the experimental situation. The scale must be easy and fast to use so as not to overburden the mothers with tests. The test must also be able to be used day after day to show the rapid variations in mood (Kennerley and Gath, 1986). The Zerssen self-rating scale which requires ten minutes to complete, was used. This scale has the advantage of being sensitive to rapid mood changes and of having been validated on both depressed and control subjects. It has been correlated with biological data and has been significantly correlated with other scales such as that of Beck and that of Zung Won Zerssen et al., 1974; Heiman et al., 1975). According to Bobon (1987), the Zerssen scale is the only self-evaluating mood scale that has been extensively validated in the French language. There are two versions lBfS and BfS’) which can be used alternatively. However, as the equivalence was not complete (Bobon, 1987) it was decided to use only one version (BfS), so that comparisons could be made. The scale is made up of a list of 28 pairs of antonyms. The mothers were asked to tick the adjective which best described what they felt at that particular time: ‘more one’ or ‘the other’ or ‘neither one nor the other’. An overall score was obtained by adding the results: 2 points for a negative adjective, 0 points for a positive adjective and 1 point for a ‘neither one nor the other’ response. The score became a quantitative evaluation of the mothers’ depressive mood. Each mother filled out the rating each morn-
This experiment was carried out \%ith 22 mothers who accepted to take part in the study. All mothers had a normal delivery without general anesthesia or cesarian. All mothers .iad a normal pregnancy without any serious bic&gicai or psychological complications. Al1 infants were fullterm and were clinically normal (Apgar score of 10 at 1 and 5 min). No infar : had a birth weight of less than 2750 g. The control population, whose cartis levels were compared with those of the nothers, was made up of 7 primiparas or multiparas whose age could be compared with that of the mothers (between 20 and 39 years of age) and who were observed outside a post-partum or post hospitalisation period. The saliva samples were taken between 8:00 and 9:00 AM on 6 consecutive days. These samples were then stored and assayed under the same conditions as those of the mothers monitored at the clinic after their delivery. A questionnaire was given to the mothers, to take individual informations like the existence of premenstrual syndrome (nervosity, irritability), and special illness during pregnancy. The medical file of the mothers has been read, with the gynaecologist’s permission. The sleepless night was noted every day before the tests. All the newborns stay overnight in the nursery and are bottle-fed between 10.00 p.m. and 6.00 a.m. Statistical treatment of data The data obtained were statistically treated. The normality of the data was verified with the Lilliefors test. The comparison between several means was obtained with the one-way analysis of variance for repeated measures (the measures
MEW
LEVEL 38
been demonstrated by Handley et al. (1980) and Kuevi et al. (1983). Our results show the particular nature of the 4th day when there was a higher cortisol level than either the previous or following day, whereas in general the levels progressively decreased from the 2nd to the 7th day post-partum.
OF CORTISOL
T
Inji’uenceof indiuidual variableson cortiso! level z
3
4 POSTPkRTUM
5
6
7
DAYS
Fig. 1. Evolution from the 2nd to the 7th day post-partum of the mean level (and standard error) of free salivary cortisol ir. mothers (N = 22) expressed in nmol/l.
have been repeated each day during 6 days). The comparison of two means was made with the Student’s t-test. The a posteriori comparisons between related samples were made with the Scheffe test and the independent samples with the Duncan test. The Spearman correlation coefficient was used for the CL ltions.
Results Evolution of saliclarycortisol during the first week post-~a~t~~~~ Fig. 1 shows the evolution of the mean of free salivary cortisol of 22 mothers, from the 2nd to the 7th day after delivery. The mean levels were between 14.05 nmol/l, and 25.95 nmol/l with the mean at 21.59 nmol/l and a standard deviation of 9.6. The sahvary cortisol levels were higher than the mean on the 2nd, 3nd and 4th days postpartum. From the 5th to the 7th days the mean cortisol levels progressively decreased. An analysis of variance shows that there was a significant difference between days (F = 0.549 P = 0.001) and particularly between the 7th and 2nd days and between the 7th and 4th days (Scheffe test). The overall reduction in the cortisol levels during the days following delivery has already
Variables concerning the period before pregnancy and pregnancy itself Premenstrual syndrome. The mothers who regularly had premenstrual syndromes of the anxiety type (N = S! had a significantly higher level of cortisol than the other mothers (t = 3.35 P = 0.001). Weightgain during pregnancy. The cortisol level of mothers who gained more than 15 kg (N = 8) during pregnancy was higher than those who did not gain as much (F = 0.365 P = 0.01). Professionalactivity. The cortisol level of mothers who had a professional activity during pregnancy (k = 11) was higher than those who did not (t = 2.54 P = 0.01). Hospitaiisationduring pregnancy. Mothers who were hospitalized during pregnancy had higher cortisol levels than those who were not (t = 2.57 P = 0.02). Health problems during pregnancy. Mothers who had somatic problems during preg nancy (nausea, persistant pain, etc) had higher cortisol levels than those who did not (t = 5.52 P = 0.02). Variablesconcerning post-par&m period New-bornfeeding method. The mothers who breast fed their babies (N = 14) had overall significantly higher levels of cortisol than mothers who bottle fed their infants (N = 8) (t = 2.45 P = 0.01). Th e mean for mothers who breast fed their babies was 22.93 nmol/l (SD =
235
10.91) and that for mothers who bottle fed their infants was 19.25 nmol/l (SD = 6.17). Jolivet et al. (1974) did not show the difference in the plasma cortisol levels in relation to feeding method during the days following delivery. Fig. 2 shows that the mothers who breast fed their babies had higher cortisol levels frout the 2nd to the 6th days with a maximum on the 4th day. For mothers who bottle fed their infants the maximum was observed on the 2nd day with a plateau until the 6th day. There was a marked decrease on the 7th day in both groups of mothers. There were significant differences for mothers who breast fed their babies between the 7th and 2nd days, the 7th and 3nd days, the 7th and 4th days. For mothers who bottle fed their babies the only significant difference was between the 7th and 2nd days post-partum (Scheffe test).
Insomnia. Cortisol levels tended to be higher after a sleepless night, whatever the time of night when the mother was unable to sleep (t = 1.92 P = 0.06).
Parity. Primiparas (IV = 8) had a higher level of cortisol than multiparas (1 = 4.86 P = 0.0001). The cortisol level of mothers aged less than 25 years was higher than that of mothers older than 25 years (F = 7.4 P = 0.01). However, it must be noted that the majority of primiparas were under 25 years of age. Jolivet et al. (1974) have demonstrated the importance of parity.
Comparison with control pop&ation
MEAN
LEVEL
2
OF CORTISOL
3
4 POSTPARTUM
6
s
7
DAYS
Fig. 2. Evolution from the 2nd to 7th day post-partum of the mean level (and standard error) of free salivary cortisol in mothers expressed in nmol/l in relation to newborn feeding method (breast feeding N = 14, bottle feeding N-T 8).
Delivery time. Mothers who gave birth between 6pm and midnight had higher cortisol levels than those who gave birth during the day time (F = 7.2 P = 0.0001). The other variables that were taken into account did not have a significant influence on the mothers’ cortisol levels. These non-significant variables were: age, smoker or non-smoker, attended or not classes for mothers-to-be, had anesthesia during delivery, delivery duration, sex of baby, wanted or not wanted pregnancy, difference between due time and actual delivery time, delivery season, duration of mother-baby contact time immediately after delivery.
The mean cortisol level of the control population was 14.33 nmoI/l (SD 5.91). The evolution from one day to the next during the six days of the experiment is presented in Fig. 3. There is no significant difference between the days (F = 0.56 P = 0.72). The levels obtained in our experiment do not differ from those obtained by Fiet et al. (1981) who observed a mean level of salivary cortisol of 15.47 +_0.6 nmol/l in the control population. However, our levels are significantly lower than those obtained from mothers during the week following delivery (4.33 as against 21.59) (t = 4.61 P = 0.0001). This would confirm the existence of higher cortisol levels during the clays following delivery. The 7th day after delivery, the mean level of salivary cortisol could be compared with that of our control group. Mothers’ mood Fig. 4 shows the evolution from the 2nd to the 7th day after delivery of the mean mood ratings of mothers according to the Zerssen Scale. The overall average rating was 1.85 (SD 1.04) which corresponds to an overall relaxed mood level.
736 MEAN
10
LEVEL
MEAN
OFCORTISOL
_ 1
2
3
4
5
6
2
3
4 POSTPARTUM
DAYS
Fig. 3. Evolution during 6 days of the mean level (and standard error) of free salivary cortisol expressed in nmol/l for the control population (N = 7).
However, there was a higher rating on the 3nd day post-partum than on the other days, indicating that there were more anxious or depressed mothers on this day, because with the Zerssen scale the higher the score, the more the mood is depressed. The mothers’ mood rating slightly decreased over the following days, but the variations were not significant (F = 0.96 P = 0.44). There was a significant difference between mothers who breast fed their babies and those who bottle fed their infants. Mothers who breast fed their babies were more depressed (mean 2.02 as against 1.57, t = 3.27 P = 0.001). Fig. 5 shows the evolution of the mothers’ mood in relation to feeding method. There is a difference every day except the 4th day post-partum. others who were hospitalized during pregnancy tended to be more depressed than those MEAN 2.5
5
6
7
DAYS
Fig. 5. Evolution from the 2nd to the 7th day post-partum of the mood ratings by mothers on the Zerssen Scale (mean and standard error) in relation to newborn feeding method (breast feeding N = 14, bottle feeding N = 8).
who were not (t = 4.11 P= 0.001). The other parameters noted above did not have a statistically significant influence on the mothers’ mood. When a finer analysis is made of the evolution of each of the 22 mothers’ m _ad, there would appear to be three distinct groups: 1. Mothers whose score was never over 2 during the week after birth. These mothers were considered to be relaxed. 2. Mothers whose score was 3 during at least cne day, but did not have a score over 3. These mothers were considered to be anxious. 3. Mothers whose score was 4 or 5 during at least one day. This score characterizes a moderately OS’extremely depressed state. These mothers were considered to be suffering from postpartum blues. In our population of 22 mothers, 14 were relaxed, 3 were anxious and 5 were depressed. This latter figure indicates that approximately 22% of the mothers suffered from transitory post-partum depression. The days when the mothers were depressed were day 3, and to a lesser extend, day 4 post-partum. CortisolLevelsand mothers’ mood
2
3
4 POSTPARTUM
S
6
7
DAYS
Fig. 4. Evolution from the 2nd to the 7th day post-partum of the mood scores by mothers on the Zerssen Scale (mean and standard error) (N = 22).
The above results indicate that the mothers who breast fed their babies had higher cortisol levels than the other mothers and tended to be more depressed.
237
There is a tendency towards a statistical correlation between the cortisol levels and mothers’ mood on the 3nd (r = 0.27 P = 0.1) and the 5th day post-partum (r = 0.28 P = 0.1). This correlation was positive and indicates that the higher the cortisol level, the more the mood rating is of a depressive type. However, there is no correlation on the other days (2nd day Y= 0 P= 0.3, 4th day r =0.12 P = 0.28, 6th day r = 0.12 P = 0.28, 7th day r = 0.18 P = 0.22). When the baby was bottle fed the mothers’ mood rating and their cortisol level are significantly correlated on the 3nd day (r = 0.69 P = 0.021, the 7th day (r = 0.64 P = 0.051, and a tendency appears on the 5th day (r = 0.53 P = 0.08). No one correlation appears when the baby was breast fed. There was no significant difference between the cortisol levels of the three groups of mothers that were made according to their mood (F = 0.7
P = 0.49). However, all three groups show an increase in cortisol levels on the 4th day post-partum.
The major interest of this study is that daily measurements were taken when the mothers were in a stable environment; maternity hospital. This daily monitoring is only possible when stress-free techniques are used, this is the case when steroid hormone assays are made from saliva. The mood self-rating scale that was used can be administered repeatedly within short periods of time. These techniques can be used with a larger population. It would be of interest to take measurements at different times of the day, as little is known about the evolution of circadian mood rhythms during the days after delivery. The Zerssen Mood Scale does not provide a detailed analysis of the different aspects of postpartum psychological disorders, but the results of this study would indicate that it can be a starting and reference point which could be completed by the use of other diagnostic instruments (Bonnin, in press). Specific instruments such as the Edinburgh Postnatal Depression Scale (Cox, 1986;
Harris et al., 1989) have not yet been translated and adapted to the French language. The progressive decrease of cortisol levels in mothers between the 2nd and 7th days postpartum follow the progressive cortisol increase that has been observed during pregnancy and that reaches a peak at delivery (Jolivet et al., 1974; Batra and Grundsell, 1978; Handley et al., 1980; Kuevi et al., 1983). The increase in corticosteroid secretion is probably associated with the physical and psychological stress of delivery, but it also enables the mobilisation of muscular energy required for labour. The decrease in cortisol levels during the week that followed delivery was not linear as there was a transitory increase on the 4th day. It must be noted that this increase occurred the day after a higher frequency of depressive states in the mothers. The cortisol levels in mothers are influenced by a number of variables. Some of them highlight the existence of physical and psychological difficulties during pregnancy (weight gain, hospitalization, carrying on a professional activity during pregnancy, health problems during pregnancy). Women who were hospitalized during pregnancy then had the risk of giving premature birth. Our findings show that these risks had psychophysiological effects which could be observed after delivery. These mothers not only had higher cortisol levels than other mothers, but they were also more depressed. The influence of the delivery time would suggest that the modifications in the cortisol circadian secretory rhythms are linked to an absence of sleep during a part of the night. This can be associated with the results concerning the influence of insomnia. Our findings also highlight the influence of the feeding method variable. Mothers who breast fed their babies had a more depressive mood and higher cortisol levels than the other mothers. The major differences between mothers who breast or bottle feed their babies is the secretion of prolactin. In the case of mothers who bottle feed their babies, this secretion is inhibited by a drug administered on the first day post-partum. Certain authors have observed a correlation between
the level of prolactin and depressive moods, but it must be noted that this correlation has been put into question (Zarifian and Loo, 1982). Our findings show that, when proiactin is inhibited, there is a significant correlation between mothers’ mood and their cortisol level. This study confirms the existence of psychophysiological changes on the 3nd and 4th days post-partum which can have a pathological aspect for approximately 22% of the mothers. However, no one-to-one relation between mothers’ mood and their cortisol levels was observed in our population. There was a correlation between the two parameters in the case of mothers who bottle fed their baby. The increase in cortisol level on the 4th day was observed in both the mothers who were suffering from baby blues and those who were not. It can be thought thal research on the etiology of post-partum depression needs to include individual variables which could modify the biological parameters being studied. Some of the contradictions found in the literature dealing with the etiology of post-partum disorders couid be due to the absence of an analysis of these variables. Our results demonstrate the complexity of the phenomena observed and the difficulty of isolating all the aspects of the etiology of psychological post-partum disorders. However, the realisation and knowledge of factors predisposing mothers to or correlating with psychological post-partum isorders could help to prevent these disorder< from becoming the onset point for more severe post-partum depression. The question is of importance when the consequences of post-partum disorders on the genesis of mother-infant attachment and the psychological development of the child a~ taken into account. References Batra S. and Grundseii,H. (1978) Studr-s on certain aspects of progestenme and cortisoi dynamic, before, during and after iabour. Ciin. Endocrinol. 8, 403~400. Bonnin, F. (1992) Ddtection des itat\ dipressifs du postpartum avec I’Cchelle d’auto-ivaluation de Zerssen, L’EncCphale (in press). Bonnin, F., Taillard, C. and Montagner, H. (lY901 Variations
quotidiennes et saisonnikres de la sensibiliti oifactive des m&es aprCs I’accouchement et de ieurs capacites de discrimination vis-g-vis de i’odeur corporelle de ieuir nouveau-&. Don&es priiiminaires. J. Gyn&oi. Obstttr. Biol Repro. 19, 165-170. Bobon, D. (1987) Psychopathologic quantitative et mesure du changement. in: Mendlewicz. J. (Ed.), Manuel de psychiatrie, Masson, Paris. 11-20. Brockington, I.F., Kumar, R. (1982) Motherhood and mental illness, Academic Press, New-York. Carpenter, W.T. and Bunney, W.E. (19711) Adrenal cortical activity in depressive illness. Am. J. Psychiatry, 128, 31-40. Cox, J.L., Connor, Y. and Kendeii, E. (1982) Prospective study of the psychiatric disorders of childbirth. Br. J. Psychiatry, 140, 1I l- 117. Dalton. K. (1980) Depression after childbirth, Oxford University Press. Feksi. A., Harris. B., Walker. R.F., Riad-Fahmy, D. and Newcombe. R.G. (1984) Maternity blues and hormone levels in saliva. J. Affect. Dis. 6. 351-355. Fiet. J.. Passa, P., Guechot, J.. Gourmei. B., Viiiette, J.M. and Cathelineau, G. (1981) IntCrit du dosage du cortisoi dans la saiive. Nouvelie Presse Mid. 32, 2664. Gaien, F.X., Pesquies, P., Menard, J., Corvoi. P. (1073) Excretion des St&ides parotidiens en relation avec les variations de la cortisoiimie. Annie Bioi. Clin. 31, 459-465. Geider, M. (lY78) Hormones and post-partum depression. In: M. Sandier (Ed.), Mental illness in pregnancy and the puerperium. Oxford University Press pp. 80-90. Handiey, S.L., Dun, T.L.. Waldron, W. and Baker, J.M. (1980) Tryptophan. cortisoi and puerperal mood. Br. J. Psychiatry, 136, 498-508. Heiman. H.. Bobon-Schrod, H., Schmocker, A.M. and Bobon, D.P. (1975) Auto-ivaluation de i’humeur par une liste d’adjectifs, la “Befindiichkeits-Skaia” (BS) de Zerssen, L’enciphaie, 1, 165-183. Hopkins, J., Marcus, M. and Campbell, S.B. (1984) Postpartum depression: a critical review. Psycholog. Bull. J5, 498-5 15. Joiivet, A., Blanchier. H., Gautray. P. and Dhem, N. (1974) Blood cortisoi variations during late pregnancy and labor. Am. J. Obst. Gynecol. 119, 775-782. Kendeli, R.E., Ckenzie, W.E., West, C., McGuire, R.J. and Cox, J.L. (1083) Day-to-
