Objective: Bipolar affective disorder and borderline personality disorder have long been considered to have significant similarities and comorbidity. This review endeavours to clarify the similarities and differences between these disorders, with an effort to determine whether they reflect different forms of the same illness or separate illness clusters.
Method: The published literature relating to bipolar affective disorders, borderline personality disorders, and related areas of knowledge was reviewed using searches of several electronic databases (AMED, CINHAL, Embase, Ovid, ProQuest, MEDLINE, Web of Science, ScienceDirect) and published texts. These findings were combined with the personal clinical experience of the author, and information gathered from colleagues, to create a review of this topic.
Results: Bipolar affective disorders and borderline personality disorders differ with respect to sense of self, disruption of relationships, family history of bipolar disorders, the benefits of medications, the extent of cognitive deficits, the form of affective dysregulation and mood cycling, the incidence of suicide and suicide attempts, the form of psychotic episodes, the incidence of early sexual abuse but not early trauma in general, the loss of brain substance, alterations in cortical activity, glucocorticoid receptor sensitivity, and mitochondrial dysfunction. They are similar with respect to non-specific features of affective dysregulation, the incidence of atypical depressive features, the incidence of self-mutilation, the incidence of transporter polymorphisms, possible genetic linkages, overall reduction in limbic modulation, reduction in the size of hippocampi and amygdala, and the incidence of sleep disruption.
Conclusions: This review concludes that bipolar affective disorders and borderline personality disorder are separate disorders, but have significant elements in common.