Bipolar disorder, borderline personality disorder or borderline bipolar? Negotiating the blurred boundaries between psychosocial and biomedical categories

Psychiatric diagnosis has become a pervasive aspect of modern culture, exerting an increasing influence on forms of personhood, identity practices, and modes of self-governing. Drawing on clinical observations and interviews, this chapter will explore the different identificatory practices surrounding bipolar disorder and borderline personality disorder. These diagnoses can be difficult to distinguish clinically due to shared symptomatology and yet are considered as highly distinct etiologically, exposing the continuing impact of mind/brain and psychotic/ neurotic dualisms within psychiatry. The radically different social and moral implications of these diagnoses explain tendencies for individuals to actively identify with bipolar disorder, whilst resisting borderline personality disorder. This chapter considers the moral and personal consequences of diagnostic membership, exclusion, and uncertainty in relation to borderline and bipolar, highlighting the ways in which individuals interact with and actively negotiate their diagnosis. It also critically examines dualistic thinking in psychiatric practice.