Bordering on the bipolar: a review of criteria for ICD-11 and DSM-5 persistent mood disorders

SUMMARYThe principal manuals for psychiatric diagnosis have recently been updated (ICD-11 was released in June 2018 and DSM-5 was published in 2013). A common diagnostic quandary is the classification of people with chronic low mood, especially those with repeated self-harm (‘emotionally unstable’ or ‘borderline’ personality disorder). There has been a great interest in use of type II bipolar affective disorder (‘bipolar II disorder’) as a less pejorative diagnostic alternative to ‘personality disorder’, despite the radically different treatment options for these disorders. DSM-5 (but not ICD-11) clearly distinguishes between borderline personality disorder and bipolar II disorder, indicating that intense emotional experiences (such as anger, panic or despair; irritability; anxiety) should persist for only a few hours in people with a personality disorder. Both manuals now use the term ‘borderline personality disorder’ rather than ‘emotionally unstable personality disorder’. The diagnostic criteria for cyclothymic disorder remain confusing.LEARNING OBJECTIVESAfter reading this article you will be able to: •appreciate the key differences in diagnostic classification between persistent mood disorders: bipolar II disorder, borderline personality disorder and dysthymia•be aware of the modest differences between ICD-10, ICD-11 and DSM-5 in diagnostic criteria for these disorders•appreciate that intense emotional experiences need persist for only a few hours to meet criteria for DSM-5 borderline personality disorder and that persistent emotional dysregulation (e.g. irritability, impulsiveness, disinhibition) for a few days meets criteria for DSM-5 bipolar II disorder.