1. Bipolar II controversy
2. DSM-5 bipolar classification
3. Bipolar spectrum debate
4. Mental health diagnosis accuracy
5. Bipolar disorder misdiagnosis

Throughout the centuries, our understanding of mental health has evolved significantly, leading to the identification and classification of various disorders. The Diagnostic and Statistical Manual of Mental Disorders (DSM) by the American Psychiatric Association serves as a principal authority for psychiatric diagnoses. Recently, an article published in the Canadian Journal of Psychiatry has stirred a contentious discussion within the psychiatric community. Professors Gin S. Malhi and Tim Outhred, along with Lauren Irwin, from the University of Sydney, posited in their paper, titled “Bipolar II Disorder Is a Myth,” that the current classification might be misleading and problematic (Malhi et al., 2019).

DOI: 10.1177/0706743719847341

In this article, we elaborate on the arguments presented by the authors, discuss the implications of their findings, and analyze the reactions and potential repercussions within the medical and psychiatric communities. We will explore the established definitions, examine the critiques of the bipolar II classification, and delve into historical perspectives and proposed alternatives.

The Established Classification of Bipolar II Disorder

Bipolar disorder is broadly characterized by mood swings that include emotional highs (mania or hypomania) and lows (depression). The DSM distinguishes between Bipolar I Disorder, where the patient experiences full-blown manic episodes, and Bipolar II Disorder, where the hypomanic episodes are more subdued and do not reach the severity of true mania (American Psychiatric Association, 2013).

This differentiation was first introduced to appreciate the subtler forms of the disorder, steering clear from monolithic perspectives that emphasized overt mania. Despite being enshrined in the DSM and the International Classification of Diseases (World Health Organization, 2018), Bipolar II Disorder’s legitimacy is not universally accepted.

The Contention Surrounding Bipolar II Disorder

Malhi et al. (2019) challenged the existence of Bipolar II Disorder on several fronts. They argue that the current classification system inflates the prevalence of bipolar diagnoses by encompassing a spectrum too broad to be clinically useful. Their critiques lie in part on the expansive and, as they suggest, somewhat arbitrary nature of hypomania’s definition, which risks pathologizing normal human behavior.

Their views are shared by a number of researchers who have also questioned the reliability and validity of the bipolar spectrum (Akiskal, 2007; Frances & Jones, 2012). Hypomanic episodes are notoriously difficult to pinpoint as they often lack the obvious disruptions seen in full-blown manic episodes, potentially leading to over-diagnosis or misdiagnosis (Ruggero et al., 2010).

Concerns are also raised about the potentially harmful consequences of incorrect diagnosis, which might lead to inappropriate treatment strategies (Agalawatta et al., 2017; Ghaemi & Dalley, 2014). Over-medication, particularly with mood stabilizers or antipsychotics, can lead to unwanted side effects such as mental clouding and sedation (Seale et al., 2007).

Historical Perspectives and Alternative Views

The bipolar II classification has been revolutionized several times since its inception. Dunner et al. (1976) originally described it to capture the less severe variations of bipolar disorder, thinking it would pave the way for more precise treatment and understanding. However, as Malhi et al. (2019) highlight, it became a catch-all category, widening the bipolar spectrum to an arguably unmanageable extent.

Alternative views propose focusing on the dimensional aspects of mood disorders, looking at symptoms on a continuum rather than discrete categories (Parker et al., 2018; Angst et al., 2012). These perspectives suggest that what has been called Bipolar II Disorder might be better conceptualized as part of a broader affective mood dysregulation condition.

Reactions within the Psychiatric Community

The assertion that Bipolar II Disorder is a myth has undoubtedly sparked debate. Proponents of the bipolar spectrum argue that the nuanced differences between Bipolar I and II are essential for determining treatment and understanding the etiology of mood disorders (Vieta & Suppes, 2008; Judd et al., 2005). The importance of recognizing the uniqueness of hypomanic episodes in Bipolar II Disorder is emphasized as essential for patient care and outcomes (Saunders et al., 2015; Geddes et al., 2009).

Detractors, on the other hand, back Malhi et al.’s claim, suggesting that the expansion of bipolar diagnoses has led to “diagnostic inflation” and “overmedicalization” (Healy, 2006; Blader & Carlson, 2007). They argue that a more restrictive diagnostic threshold would prevent misdiagnosis and improve treatment specificity (Fletcher et al., 2013).

Implications for Diagnosis and Treatment

The ongoing debate has significant implications for both diagnosis and treatment of mood disorders. If Malhi et al.’s (2019) views were to gain consensus, it might lead to a paradigm shift, where fewer individuals would be diagnosed with Bipolar II Disorder and the focus might shift towards identifying and treating mood dysregulation more generally. It could also influence pharmacological strategies, promoting a more conservative approach and possibly reducing the use of antipsychotic medications (Pringsheim & Gardner, 2014).


The challenges to the existence of Bipolar II Disorder are far from reaching a resolution. This debate reflects the broader questions faced by psychiatric classification systems, balancing the need for precision with the dangers of over-categorization (Parker & Fletcher, 2014). Future research, clinician education, and a re-examination of psychiatric diagnostic criteria will likely continue to shape this ongoing conversation.

Empirical and clinical evidence will be required to either further validate the existence of Bipolar II Disorder or to overhaul its classification. Novelties such as neuroimaging and genetic studies may also shed new light on the subject (Phillips & Swartz, 2014). The narrative of Bipolar II Disorder being ‘a myth’ challenges the psychiatric community to refine its diagnostic tools and to ensure the best possible outcomes for patients worldwide.

This article examined the provocative claim that Bipolar II Disorder may not exist as a distinct clinical entity. The discussion is founded on reputable references, including both supporting and contesting viewpoints, which provide a rich base for further exploration and debate. As the discussion unfolds, it’s clear that what is ultimately at stake is the well-being of millions of individuals who rely on accurate psychiatric diagnoses to navigate their mental health journeys.


American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: American Psychiatric Publishing.

Akiskal, H. S., et al. (2007). The emergence of the bipolar spectrum: Validation along clinical-epidemiologic and familial-genetic lines. Psychopharmacology Bulletin, 40(4), 99–115.

Angst, J., et al. (2012). Diagnostic criteria for bipolarity based on an international sample of 5,635 patients with DSM-IV major depressive episodes. European Archives of Psychiatry and Clinical Neuroscience, 262(1), 3–11.

Malhi, G. S., et al. (2019). Bipolar II Disorder Is a Myth. Canadian Journal of Psychiatry, 64(8), 531–536. doi: 10.1177/0706743719847341

Parker, G., et al. (2018). Revising diagnostic and statistical manual of mental disorders, criteria for the bipolar disorders: Phase I of the AREDOC project. Australian & New Zealand Journal of Psychiatry, 52(1173-1182).

Pringsheim, T., & Gardner, D. M. (2014). Dispensed prescriptions for quetiapine and other second-generation antipsychotics in Canada from 2005 to 2012: A descriptive study. CMAJ Open, 2(4), E225.