Borderline personality disorder (BPD) is defined within the fields of psychiatry and clincal psychology as a mental condition characterized primarily by emotional dysregulation, extreme "black and white" thinking, or "splitting" (believing that something is one of only two possible things, and ignoring any possible "in-betweens"), and chaotic relationships. It is described by mental health professionals as a serious mental illness characterized by pervasive instability in mood, interpersonal relationships, self-image, identity, and behavior, as well as a disturbance in the individual"s sense of self. In extreme cases, this disturbance in the sense of self can lead to periods of dissociation.
The disturbances suffered by those with borderline personality disorder have a wide-ranging and pervasive negative impact on many or all of the psychosocial facets of life, including employability and relationships in work, home, and social settings.