Is Postpartum Depression a Homogenous Disorder
Is Postpartum Depression a Homogenous Disorder
In Finland, a postpartum examination is offered to all mothers at six weeks after childbirth, after the puerperium. Mothers were screened during this examination by primary care nurses at the antenatal clinic in Joensuu, Eastern Finland, using the Edinburg Postnatal Depression Scale (EPDS-10, range 0–30). The EPDS has been developed to assist primary care health professionals detect mothers suffering from postnatal depression. If the depressive symptoms of the mothers began later (i.e. up to six months after delivery) they contacted their antenatal clinic's nurse, who assessed their depression using the EPDS. If the EPDS score was ≥ 10 or there was a clinical suspicion of depression, the nurse told the mother that she could be assessed by a psychiatrist (PK) at the local General Hospital Psychiatric unit of the North Karelia Central Hospital in Joensuu. This community-based hospital unit serves a socioeconomically diverse population. All mothers who wanted to attend the psychiatric unit were evaluated by a psychiatrist at six weeks to six months after delivery. Mothers with psychotic, addictive and thyroid disorders were excluded from the study.
Diagnoses of major depressive disorder in the study group (depressed mothers) and the control group (non-depressed mothers) were assessed by a psychiatrist (PK) by means of the Structured Clinical Interview for DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, fourth edition) Axis I Disorders (SCID-I). DSM-IV uses the term "postpartum onset" as a specifier applicable to major depressive disorder, bipolar disorder or brief psychotic disorder occurring over the first four weeks following childbirth. The diagnostic criteria for a Major Depressive Episode (MDE), as defined by the DSM-IV, include five (or more) of the following symptoms: at least two weeks of persistent depressed mood, loss of interest/pleasure, increased or decreased appetite, sleep disturbance, psychomotor agitation or retardation, decreased energy, feelings of worthlessness or guilt, poor concentration, and suicidal ideation. At least one of the symptoms must be either depressed mood or loss of interest. For this study, all nine SCID symptoms – the entry criteria (depressed mood and/or loss of interest) and seven associated symptoms – were assessed in the depressed and non-depressed group. This procedure (i.e. an adaptation of the usual SCID procedure) allows comparisons of all SCID symptoms between groups.
The groups were asked questions about the onset of depression and experiences of previous depressive episodes as a part of the semi-structured SCID interviews. Previous depressive episodes were assessed by asking whether the mothers had had persistent depression (i) for at least two weeks without connection to their pregnancy or postpartum period, (ii) during pregnancy, (iii) and/or during previous pregnancies, and (iv) whether they had had previous postpartum depression in the period up to six months after delivery. The answers were classified as yes or no. The onset of PPD was assessed by asking how soon after childbirth the depression began. This was reported as weeks after delivery. The mothers were also asked if they had given birth to a living infant or not, and how many children they had.
The severity of depression was rated using the number of MDE-positive symptoms found in the SCID interview, the self-administered 21-item Beck Depression Inventory (BDI-21, range 0–63), and the 10-item EPDS. The level of hopelessness was assessed by the 20-item Beck Hopelessness Scale (BHS-20, range: 0–20).
Mental symptoms were assessed by the 90-item Symptoms Checklist 90 (SCL-90). The SCL-90 measures symptom intensity on nine different subscales, including somatisation, obsessive-compulsive symptoms, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideation, and psychoticism. The SCL-90 is capable of differentiating healthy and mentally ill subjects, and its discriminant validity is good in the Finnish population. High intercorrelations were found between the nine original subscales. However, the checklist is not capable of distinguishing between different diagnostic groups.
The study protocol was approved by the Ethical Committee of the North Karelian Hospital District Federation of Municipalities. All participants gave their informed consent prior to data collection.
The final study group consisted of 104 mothers with a major depressive episode, aged 18–40 years. The participants expressed their willingness to participate in this study. Data collection took place from 2003 to 2013. A control group of non-depressed mothers was collected at the antenatal clinic in Joensuu. If the EPDS score was <10 in postpartum examinations, primary care nurses asked if the mothers were willing to participate in the non-depressed group of mothers and then organised psychiatric evaluation. The final control group consisted of 104 non-depressed mothers, evaluated six weeks to six months after delivery and aged 18–40 years. The control group was collected between 2008 and 2010. Mothers with psychotic, addictive and thyroid disorders were again excluded.
Data analysis was conducted with IBM SPSS (version 21). The differences between the study groups were examined with Pearson's chi-square test and Fisher's exact test for the categorical variables, and the independent samples t-test was used for the continuous variables. If a continuous variable was not normally distributed, the non-parametric Mann–Whitney U test was used. The statistical significance of the tests was defined as 0.05. The relationship between previous depression and current PPD was investigated using age-adjusted logistic regression.
Methods
In Finland, a postpartum examination is offered to all mothers at six weeks after childbirth, after the puerperium. Mothers were screened during this examination by primary care nurses at the antenatal clinic in Joensuu, Eastern Finland, using the Edinburg Postnatal Depression Scale (EPDS-10, range 0–30). The EPDS has been developed to assist primary care health professionals detect mothers suffering from postnatal depression. If the depressive symptoms of the mothers began later (i.e. up to six months after delivery) they contacted their antenatal clinic's nurse, who assessed their depression using the EPDS. If the EPDS score was ≥ 10 or there was a clinical suspicion of depression, the nurse told the mother that she could be assessed by a psychiatrist (PK) at the local General Hospital Psychiatric unit of the North Karelia Central Hospital in Joensuu. This community-based hospital unit serves a socioeconomically diverse population. All mothers who wanted to attend the psychiatric unit were evaluated by a psychiatrist at six weeks to six months after delivery. Mothers with psychotic, addictive and thyroid disorders were excluded from the study.
Diagnoses of major depressive disorder in the study group (depressed mothers) and the control group (non-depressed mothers) were assessed by a psychiatrist (PK) by means of the Structured Clinical Interview for DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, fourth edition) Axis I Disorders (SCID-I). DSM-IV uses the term "postpartum onset" as a specifier applicable to major depressive disorder, bipolar disorder or brief psychotic disorder occurring over the first four weeks following childbirth. The diagnostic criteria for a Major Depressive Episode (MDE), as defined by the DSM-IV, include five (or more) of the following symptoms: at least two weeks of persistent depressed mood, loss of interest/pleasure, increased or decreased appetite, sleep disturbance, psychomotor agitation or retardation, decreased energy, feelings of worthlessness or guilt, poor concentration, and suicidal ideation. At least one of the symptoms must be either depressed mood or loss of interest. For this study, all nine SCID symptoms – the entry criteria (depressed mood and/or loss of interest) and seven associated symptoms – were assessed in the depressed and non-depressed group. This procedure (i.e. an adaptation of the usual SCID procedure) allows comparisons of all SCID symptoms between groups.
The groups were asked questions about the onset of depression and experiences of previous depressive episodes as a part of the semi-structured SCID interviews. Previous depressive episodes were assessed by asking whether the mothers had had persistent depression (i) for at least two weeks without connection to their pregnancy or postpartum period, (ii) during pregnancy, (iii) and/or during previous pregnancies, and (iv) whether they had had previous postpartum depression in the period up to six months after delivery. The answers were classified as yes or no. The onset of PPD was assessed by asking how soon after childbirth the depression began. This was reported as weeks after delivery. The mothers were also asked if they had given birth to a living infant or not, and how many children they had.
The severity of depression was rated using the number of MDE-positive symptoms found in the SCID interview, the self-administered 21-item Beck Depression Inventory (BDI-21, range 0–63), and the 10-item EPDS. The level of hopelessness was assessed by the 20-item Beck Hopelessness Scale (BHS-20, range: 0–20).
Mental symptoms were assessed by the 90-item Symptoms Checklist 90 (SCL-90). The SCL-90 measures symptom intensity on nine different subscales, including somatisation, obsessive-compulsive symptoms, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideation, and psychoticism. The SCL-90 is capable of differentiating healthy and mentally ill subjects, and its discriminant validity is good in the Finnish population. High intercorrelations were found between the nine original subscales. However, the checklist is not capable of distinguishing between different diagnostic groups.
The study protocol was approved by the Ethical Committee of the North Karelian Hospital District Federation of Municipalities. All participants gave their informed consent prior to data collection.
The final study group consisted of 104 mothers with a major depressive episode, aged 18–40 years. The participants expressed their willingness to participate in this study. Data collection took place from 2003 to 2013. A control group of non-depressed mothers was collected at the antenatal clinic in Joensuu. If the EPDS score was <10 in postpartum examinations, primary care nurses asked if the mothers were willing to participate in the non-depressed group of mothers and then organised psychiatric evaluation. The final control group consisted of 104 non-depressed mothers, evaluated six weeks to six months after delivery and aged 18–40 years. The control group was collected between 2008 and 2010. Mothers with psychotic, addictive and thyroid disorders were again excluded.
Data analysis was conducted with IBM SPSS (version 21). The differences between the study groups were examined with Pearson's chi-square test and Fisher's exact test for the categorical variables, and the independent samples t-test was used for the continuous variables. If a continuous variable was not normally distributed, the non-parametric Mann–Whitney U test was used. The statistical significance of the tests was defined as 0.05. The relationship between previous depression and current PPD was investigated using age-adjusted logistic regression.