Introduction
Depression is a focal public health question. In the childbearing period, it is commoner in females than in males with a 2:1 ratio. According to the Department of Mental Health and Substance Abuse-World Health Organization (2008), postpartum depression is at least an event of non psychotic depression fulfilling the standard diagnostic measures, up to one year after childbirth. Globally, postpartum depression affects about 13% of women. The incidence of female depression is only 10 to 15% higher as related to childbirth than in non pregnant females of the same age group. Yet, the incidence of first onset depression episode and depression severity is three times higher after childbirth than in counterpart non pregnant females. Postpartum depression is an important health problem to deal with as research evidence suggests that interim (temporary) negative outcomes include maternal emotional, behavioral, and cognitive, abilities. It also affects and interpersonal developmental progress of young children. On the other hand, long-lived or recurring episodes of postpartum depression may seriously affect the mother child relationship (Department of Mental Health and Substance Abuse-World Health Organization report, 2008). The aim of this essay is to review postpartum depression with emphasis on hormonal and other physiological risk factors.
Epidemiology
A report of the American Psychological Association (2007) inferred that 9 to 16% of females in the postpartum period suffer from postpartum depression. Further, among those who suffered postpartum depression (PPD), the incidence rises to 41% for the following deliveries.
The Centers for Disease Control and Prevention (CDC) issued in April 2008 a study on the prevalence of self-reported PPD in 17 states. The prevalence rate ranged from 11.7% in Maine to 20% in New Mexico, with an average of 15%. The study showed that younger females, with lower educational levels are reporting PPD more than others, In addition, females received Medicaid refund for their delivery report PPD more than who did not. About demographic prevalence, the study displayed that non Hispanic white females have the lowest prevalence compared to other ethnic groups. Females who used to smoke before or during pregnancy, those who were subjected to physical abuse or suffered emotional or financial problems even related to their partners are more prone to PPD. Mothers who gave birth to low birth infants or whose infants admitted to neonatal ICU are also more prone to PPD. Of interest, 54.2% of PPD mothers have had at least a depression episode either before or during pregnancy.
Variants of postpartum mood disorders
Postpartum mood disorders include various emotional and psychological changes that can be interpreted as a scale of symptoms stepping up in severity overtime. According to Stone and Menken (2008), there are three common types or grades of mood disorders in the postpartum period, baby (postpartum) blues, postpartum depression (PPD), and postpartum psychotic illness. About baby (postpartum) blues, it is an adjustment disorder with a depressed mood rather than a depressive disorder. It affects 50 to 70 % of postpartum mothers, and is directly related to hormones levels’ changes after delivery, with the patient is sad enough to weep as a key feature. Postpartum depression is one step further in severity; the patient is at high risk on the fourth week postpartum or on weaning. Postpartum psychosis, the most severe condition, it occurs in 0.14% to 1 each 1000 postpartum cases, and can occur any time within the first three months after delivery (Stone and Menken, 2008).
Risk factors of postpartum depression
Hiltunen (2003) classified the risk factors of postpartum depression (PPD) into five groups namely; hormonal, psychiatric, social factors, factors related to delivery (obstetric), and facto related to the infant. The sudden biological changes that take place after delivery directed many researchers to the possibility of hormonal etiology to PPD. However, the inconsistency of results and the difficulties of hormonal assessment in peripheral blood samples lead others to the belief of a psychiatric etiology. This view relies on the assumption that as childbirth is a major stress, it can produce depression in vulnerable patients (Hendrick and others, 1998).
Hormonal factors
Parry and others (2003) reviewed the literature about hormonal basis of mood and postpartum disorders besides their study on 20 patients. Parry and others conducted their review focusing on five topics, the pituitary-gonad area, the pituitary thyroid, and hypothalamic pituitary adrenal topic. About estrogen, they inferred that regression of depression symptoms matches rise in serum estradiol level; further, with treatment by estrogen, the symptoms decrease as serum estradiol level comes near to that of the follicular phase of the menstrual cycle. With progesterone, both serum progesterone and progesterone-5 dihydroprogesterone ratio were higher in PPD females than those with no depressive symptoms. Meanwhile, the ratio between pregnanolol and progesterone is lower in PPD females. According to Hiltunen (2003), inferred that thyroid hypofunction is displayed in nearly 12% of females with PPD, Hiltunen (2003) explained that is because of availability of thyroid antibodies. Based on their findings, Parry and other (2003) inferred that their findings suggest decreased night cortisol serum level directly after delivery possibly because of decreased adrenocorticotrophic hormone level. About prolactin hormone, females with PPD have low prolactin serum levels. This explains why mothers who breast-feed their infants have lower incidence of PPD because of higher prolactin serum level associated with breast-feeding Parry and other (2003). Based on the findings of Wieck and others (1991) (after Parry and other, 2003), Parry and colleagues (2003) suggested that increased sensitivity of dopamine receptors in the postpartum period may play a role inducing PPD.
Psychiatric factors
Robertson and others (2003) reviewed the psychiatric risk factors for postpartum depression and suggested they related either to previous history of psychiatric disorders or to individual’s psychological construct (build up). Previous history of psychological problems has always been found associated with high risk of postpartum depression, with nearly the highest effect size among all risk factors. This may point to postpartum depression being a continuation of depressive moods during pregnancy. O’Hara and Swain (1996) (after Robertson and others, 2003) reviewed five studies including 550 females who were overanxious or neurotic before labor. They inferred that although all of them were able to think logically and mix well socially yet, there was moderate association between their antenatal anxiety and postpartum depression. Robertson and others (2003) reviewed two more recent studies and suggested important association between neuroticism and postpartum depression. Robertson and others (2003) reviewed the literature about cognitive attribution construct in response to emotional experiences. They suggested that pessimistic or negative cognitive attribution construct is significantly associated with postpartum depression. McGuffin and others (2006) inferred that childbirth experience may be a triggering factor for PPD, especially in the first 6 to 8 weeks after delivery in patients with positive family history or recurrent episodes of PPD.
Social factors
Many epidemiological studies display enough data to suggest how important are social factors in triggering PPD. Lack of social support from family and friends besides lack of practical support (baby-sitting and help in housework) are associated with increased incidence of PPD (Hiltunen, 2003). Roberts and others (2003), and Hiltunen (2003) inferred that partner’s (baby’s father) support is probably the most important social support the mother needs. Studies also show the baby’s father is at risk of depression whether the mother suffers early PPD within the first six weeks or delayed PPD up to one year postpartum. Bottle-feeding, unemployment, and single mothers status, are also associated with higher incidence of PPD. The studies reviewed by Robertson and others (2003) showed significant difference between social support expected by PPD mothers and the already received social support (both overall and from the partner). The studies reviewed by Hiltunen (2003), and Robertson and colleagues (2003) were cross-sectional studies (no follow up data), focused on low-income mothers. There were no studies comparing social support association in native and non native (immigrant mothers).
Factors related to delivery (obstetric factors)
Many studies displayed the method of delivery (Cesarean section versus vaginal delivery) relates to PPD incidence. Hiltunen (2003) showed that Cesarean section (CS) is associated with higher PPD incidence; moreover, emergency CS is more traumatic to the mother and relates to higher PPD incidence that elective surgery. The place of delivery (home or hospital) did not relate significantly with PPD, and assisted labor by episiotomy, or induction of labor did not show specific relation to PPD (Hiltunen, 2003). About pain, history of gynecological pain whether related to menstruation, intercourse, or because of a pathology is not related to increased incidence of PPD, although significantly relates to pain during delivery (Hiltunen, 2003). Using analgesics during labor relates well to dissatisfaction with labor but not to PDD (Hiltunen, 2003). Robertson and others (2003) in their review analysis identified that most of the studies were preplanned (prospective) in design, with non uniform methods of depression evaluation (interviews, or self-reported measures). Further, some variables were not independent especially with CS as the decision varies according to consultant’s preference, maternal culture and preference, also maternal cultural backgrounds influence deciding breast-feeding. Therefore results in these areas should be taken with caution as they may reflect trends but not association (Robertson and others, 2003).
Factors related to the infant
The commonest infant factors related to developing PPD are infants with difficult behavior, irritable infants, and feeble motor performance (Hiltunen, 2003). As inferred by Robertson and others (2003), the predictive power of these factors is subjected to bias because first, evaluation of the infant behavior is influenced by the mother’s depressive condition. Second, these factors can only be evaluated after delivery with no base reference. Robertson and others (2003), reviewed the literature about the influence of infant’s gender, they suggested that in western developed countries it has no influence on PPD incidence. However in countries like India and China, the incidence of PPD is higher if the infant is a female, this may be because of the effect of father’s response to a female infant. Thus, in certain cultures, the infant’s gender is a possible risk factor for PPD (Robertson and others, 2003).
Predictors to postpartum depression
Beck (2002) reviewed the literature about postpartum depression prediction inventories and the various tools of predicting PPD in the prenatal period from 1978 to 1996. Beck (2002) recognized 13 predictors of PPD that are usable in obstetric clinical practice. These predictors are: prenatal depression, stress of childcare, general life stress, marital relationship satisfaction, social support, and prenatal anxiety. Previous history of PPD, or baby (postpartum) blues, and infant temper are other predictors to look for. The remaining predictors are socioeconomic condition, marital status, whether the pregnancy is preplanned or not, and self-confidence. Females are in risk of developing PPD if they have positive three to six risk factors, high risk is considered if more than six risk factors are positive (Beck, 2002).
Screening and Diagnosis of postpartum depression
Although postpartum depression does not differ clinically from depression, yet its effect on both the mother and infant brought it to public and specialists’ interest. Therefore screening of its potential is important, Cox and colleagues published the 10 items Edinburgh postnatal depression (EPDS) scale in 1987 as a research and clinical screening tool (after Santos and others, 2007). EPDS is in common among healthcare professionals and in community screening studies because it is easy to fill and well organization, its value from clinical and epidemiological viewpoints is confirmed in many studies. Its specificity and sensitivity (validation measures) range from 70% to 85% in different studies from various countries. Santos and others conducted a validation study of EPDS on 378 females with nearly the same validation results. Gjerdingen and others (2007) conducted a literature review on PPD screening instrument searching MedLine, and the Cochrane database. They suggested there is a need for further studies on larger better representative samples, better collaboration between primary healthcare providers and mental health providers, and further longitudinal cases’ studies to identify the ideal screening tool.
Robertson and others (2003) recognized another difficulty in screening of PPD that is the problem of identifying depressive symptom from somatic symptoms (weight, sleep rhythm, and regular activity changes) normally associated with giving birth, but are also symptoms of PPD.
The diagnostic and statistical manual of mental disorders (DSM-IV) of the American Psychological Association (2000) did not report PPD a separate depression disorder. Instead it is considered a major depression disorder related to childbirth. Based on DSM-IV criteria for diagnosis are depressed mood for most of the day nearly every day, notable persistent reduction of interest for almost all daily activity (or most of it). Notable weight change (reduction without diet, or gain for more than 5% within a month), and sleep disorders (insomnia or hypersomnia) are other criteria. Additional criteria include psychomotor excitation or delay, easy fatigability and loss of energy, feeling of insignificance, triviality or guilt, reduced ability to focus and dithering. Further diagnostic criteria are frequent thought of death or suicidal ideas. The symptoms are severe enough to cause impaired functioning (social, or work) and are not secondary to a drug or a medical disorder, and have a postpartum onset (onset specifier). For diagnosis one of the first two criteria should be present, further five or more symptoms (including 1 or 2 or both) within the first four weeks postpartum and display a change from previous behavior (The American Psychological Association 2000). According to Robertson and colleagues (2003) there are two methods for depression assessment either through self-reported assessment or organized interviews. Using standardized organized interviews adds to the validity of diagnosis; however; it is costly, and time consuming, therefore current trend is to keep this method for a restricted number of cases included in a research or an epidemiologic study. Second is using self-reported assessment tools, an example of which is Edinburgh postnatal depression scale. These tools have the advantage of being easy, cheaper, and do not need an available trained clinician, thus a larger sample can be evaluated. These tools have the advantage of being easier to review and redesign based on research results. There is an inherent disadvantage in this method that is the use of cut off score for diagnosis, which may express physical illness rather than a depression. Further, these tools do not usually address in detail the duration of symptoms or the extent of interference with social or work functioning (Robertson and colleagues, 2003). Two more points to consider in assessment of PPD are evaluation of the outcome of the disorder on the various activities of the depressed mother including mother-infant relationship. Second, is to realize that most cases of PPD are self-limiting and recover within months; however, there is a high risk of recurrence with future pregnancies ( then, the disorder is a chronic one) (Robertson and colleagues, 2003).
Prevention and treatment of postpartum depression
Unlike other types of major depression PPD provide a unique opportunity to prevention being linked to a predictable triggering factor that is giving birth with many risk factors identified. Wisner and colleagues (2004) defined prevention as reducing the rate of PPD in high risk females, and to decrease the frequency of recurrence. They conducted a controlled clinical trial on 22 pregnant females with a history of at least one episode of PPD. They administered an antidepressant drug (sertraline) for 17 weeks after delivery and a placebo to eight females. Their results displayed reduced rate of recurrence with farther onset than in the second (placebo) group. Wisner and colleagues (2004) inferred antidepressants provide a probable preventive measure for PPD. Dennis (2005) evaluated psychosocial and psychological measures in reducing the risk of PPD. The study of Dennis (2005) was a systematic literature review, which included 15 controlled trials with 7697 mothers included. Results displayed for all types of measures (interventions), there was no significant effect on PPD except for rigorous postpartum support given by a healthcare professional. Results also showed postpartum interventions were more useful than interventions including a postpartum and an antepartum constituent; besides, individually directed interventions gave better results than group directed ones (Dennis, 2005).
According to the University of Michigan Health System Report on depression (2005), treatment of PPD can be by medication, or psychotherapy (in mild to moderate cases), or a combination of both treatments in severe cases. About treatment with antidepressant drugs the report states there no preference of a particular antidepressant drug over other drugs. However, the drug choice depends on weighing possible side effects, previous response, and presence of associated medical or psychiatric disorder. The report acknowledges that patients starting antidepressant medication should be closely watched for symptoms worsening or suicidal tendency, the same policy should be adopted on drug withdrawal before stopping treatment. Antidepressant medication should continue for 9-12 months after remission of the acute episode, although life treatment is considered in certain cases. Education and support by healthcare professionals is an important complementary part of the treatment (University of Michigan Health System Report on depression, 2005). Buist (2008) summarized the criteria for antidepressant medication as follows: persistent severe biological symptoms like sleep disturbances, and weight changes. Insufficient responses to psychological treatment, difficulty to continue psychological treatment because of cost, distance or mother preference are other criteria to look at.
Estrogen supplementary treatment showed some positive influences in treating PPD in some case reports, while progesterone treatment displayed better even decisive results in many other studies. However, there is a need for more trials to confirm these results and to compare the possible effects of hormonal treatment (Gjerdingen, 2003).
Psychotherapy for PPD is of two types, individual directed or group therapy. The partner or infant’s father may be included in individual therapy, which generally showed superior results to group therapy. PPD patients may require about six to 12 psychotherapy sessions. On the other hand, group therapy showed inconsistent mixed results (Gjerdingen, 2003).
Nurse-midwife home visit is an important form of support provided healthcare professionals and is more common in European practice. Trials showed that weekly visits for the first 6 weeks after delivery reduced to a visit every two weeks for the next weeks resulted in improving PPD rates as evidenced by scores of Edinburgh postnatal depression scale. These visits are helpful to minimize the infant factors as well as nurse can provide proper guidance to how a mother can look after the infant (Gjerdingen, 2003).
Conclusion
Postpartum depression is a prevalent problem that affects mothers after delivery, there are many risk factors identified. If left untreated it may result in damaging influences on mothers, infants, and the whole family. Because of this attention should be directed to screening and prevention. Treatment options are many, they include antidepressant treatment, psychotherapy, and evidence shows the nurse-midwife home visits can be useful providing needed support and education to mothers. Although hormonal disturbances are known to occur during pregnancy and after delivery, yet evidence is short as to their role in the disorder etiology as well as in treating the condition.
References
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