Handbook of personality disordersChapter 23Clinical features of borderline personality disorder The borderline personality disorder suffers from heterogeneity and fuzzy boundaries. Critics of borderline personality disorder would like to define it as a variant of mood disorder. This is based on symptoms of affective instability. But this is not consistent with research literature. Patients with borderline personality disorder experience continually abnormal mood for years, may in a different mood from hour to hour, are likely to have every mood, and have a different neurobiological profile than bipolar disorder. Mood symptoms are only one of the primary symptoms of borderline personality disorder. Patients with borderline personality disorder do not have manic or hypomanic episodes. One-third of people with borderline personality disorder develop symptoms without experiencing serious childhood adversity. In the DSM-5, nine criteria for borderline personality disorder are listed, with five required to make a diagnosis. These criteria include 1) affective symptoms 2) impulsive symptoms 3) interpersonal problems 4) an unstable identity 5) cognitive symptoms The most characteristic symptom of borderline personality disorder is affective instability. Hypersensitivity to the environment leads to rapid changes of mood in response to interpersonal events, with slow recovery from distress. This doesn’t fully account for the...