Postpartum psychosis: A valuable misnomer

Postpartum psychosis: A valuable misnomer

The term ‘postpartum psychosis’ or puerperal psychosis (PP) is widely used by clinicians and researchers, but has no official nosological status in DSM-IV, DSM-5 or ICD-10. Sharma and Sommerdyk (2014) have started a very interesting debate of whether we should use PP as a distinct diagnostic label, or whether women suffering from a severe or psychotic mental illness with an onset within the first few weeks postpartum should be ‘shoe-horned’ into extant diagnostic categories.

We welcome this debate and fully agree with Sharma and Sommerdyk that the term ‘psychosis’ in postpartum psychosis is a misnomer and quite problematic. PP is generally considered an atypical presentation of a mood disorder and not primarily a ‘psychotic’ disorder. Most patients with this disorder have prominent mood symptoms including mania, mixed states and psychotic/delusional depression, with great phenotypical similarity to those seen in bipolar episodes. A much smaller subgroup of patients have non-affective psychotic symptoms or a ‘schizophrenia-like’ presentation (Bergink et al., 2011). Consequently, the term ‘psychosis’ could be considered both incorrect and imprecise. We acknowledge that ‘psychosis’ is an inappropriate description of the disorder as many of the women with it do not have ‘psychotic’ symptoms, especially those with hypomania, depression or mixed episodes. The term psychosis was used to align it with the broad group of affective psychoses that encompassed conditions such as ‘endogenous depression’ and ‘manic depressive psychosis’, but abandoned when DSM-III was introduced. However, we would argue the case of keeping the term PP despite these challenges.

There are three principal reasons to retain the concept. First, it highlights the role of childbirth as a highly specific and very significant trigger of psychiatric illness. Second, its distinct phenotype and third, its long-term course.

Postpartum psychosis is a psychiatric disorder with an intrinsically defined onset; within 4-6 weeks postpartum. The postpartum period is the highest risk period to develop a severe mental illness in a woman’s life. New onset of illness within this time frame, and its incidence is uniquely linked to PP, a phenomenon which has been observed over the centuries and across different cultures. The only other disease with intrinsically defined onset is posttraumatic stress disorder, for which the term is not questioned, despite a broadly defined clinical phenotype (Boyce and Barriball, 2010). Not only the onset, but also remission from PP is clearly defined. The overwhelming majority of PP patients experience a complete symptom remission within few months postpartum after treatment. Finally, the mechanism for onset is related to specific neurobiological changes (e.g. endocrine- and immune related changes, circadian rhythm disruption) occurring after childbirth.

Second, it should be used as a distinct diagnostic label, because it is a phenotypically well-defined entity. Previous studies have clearly described the first onset of severe affective, psychotic and cognitive symptoms specifically in the first 4-6 weeks postpartum. Interestingly, women suffering from PP do not always present with features typical of bipolar disorder (manic episode, mixed episode, depression with psychotic features) or a psychotic disorder. Many women have mood-incongruent delusions, in the absence of schizophrenia-like criteria. In addition, mood cycling appears to be a prominent feature. Finally, ‘atypical’ features are prominent among women with PP such as catatonia, depersonalization, derealization, perplexity and confusion, although the prevalence of these symptoms remains to be determined (Bergink et al., 2011). Overall, its clinical features do not fit comfortably with the current diagnostic entities.

Third, it identifies a group of women for whom their risk of psychiatric episodes is solely related to childbirth. Retrospective studies have shown that some PP cases have psychiatric episodes uniquely related to childbearing (Blackmore et al., 2013), suggesting a specific subgroup of women with a distinct prognosis and disease trajectory. We propose a model for the longitudinal course of first onset PP in which for some women the vulnerability for mania and psychosis remains exclusively limited to the postpartum period whereas for some women PP represents a signal for the onset of a lifelong course of bipolar disorder.

Previous studies have confirmed the range of diagnoses administered in the postpartum period, suggesting that the PP term may indeed be a more appropriate umbrella description for this patient group (Munk-Olsen et al., 2006; Boyce and Barriball, 2010). We suggest including all women with new onset affective and non-affective psychosis within 6 weeks postpartum in a PP definition. Specifically, we would like to include women with mania/mixed episodes with or without psychotic features, depression with psychotic features, melancholic depression, brief psychotic disorder and psychosis NOS.

There are many advantages to give first onset PP including mania and psychotic depression an official status as a discrete gender-specific diagnostic entity. This can aid in reducing stigma as women will not immediately be diagnosed with a life-long illness such as bipolar affective disorder, but instead be diagnosed with ‘a postpartum condition’. It also has major consequences for treatment recommendations. Specifically, if not all psychotic or manic episodes postpartum convert to bipolar disorder during lifetime, use of long-term mood stabilizers is not required for all women who experience PP (Boyce and Barriball, 2010). This would also suggest that psychotropic medications could be slowly withdrawn after the acute symptoms have come under control. This is particularly important during next pregnancies. If women have successfully tapered off medication without relapse, women with only PP are not at elevated risk of psychiatric episodes during pregnancy, offering an important clinical advantage by avoiding in utero foetal exposure to prophylactic medication (Bergink et al., 2012). A distinct diagnosis with clear criteria may encourage the design of multicenter randomized trials to investigate both treatment and preventive intervention. A recent Cochrane systematic review concluded that randomized trials are completely absent for postpartum psychosis.

Childbirth triggers illness episodes, but currently there remain many unanswered questions regarding the prognosis of women with first-onset psychiatric episodes in the postpartum period. To understand PP better and evaluate if it is an appropriate definition/term we eagerly await heritability studies looking at genetic liability to triggering of psychiatric episodes after childbirth, and both clinical and epidemiological studies looking at prognosis and outcomes among women with first onset postpartum psychiatric episodes. More research can lead to official treatment algorithms and distinct prevention plans for subsequent pregnancies, and it would facilitate long-term recommendations, which is urgently needed.

Overall, we believe that a classification of first-onset PP as a distinct gender-specific diagnostic entity is beneficial for patients and for research purposes. We welcome the debate on the term PP, but suggest that we do not abandon this definition to keep clinicians and researchers focused on the specific risk of psychiatric symptoms triggered by childbirth.