Psychotic symptoms in patients with borderline personality disorder (BPD) are common, distressing to patients, and challenging to treat. Issues of comorbidities and misdiagnoses in BPD patients further complicate matters and could lead to iatrogenic harm. The dissociation that patients with BPD experience could be confused with psychosis and exacerbate treatment and diagnostic confusion. Furthermore, BPD patients with unstable identity and who are sensitive to rejection could present in a bizarre, disorganized, or agitated manner when under stress.

Although pitfalls occur when managing psychotic symptoms in patients with BPD, there are trends and clues to help clinicians navigate diagnostic and treatment challenges. This article will review the literature, propose how to distinguish psychotic symptoms in BPD from those in primary psychotic disorders such as schizophrenia, and explore reasonable treatment options.

The scope of the problem

The DSM-5 criteria for BPD states that “during periods of extreme stress, transient paranoid ideation or dissociative symptoms may occur.”1 The term “borderline” originated from the idea that symptoms bordered on the intersection of neurosis and psychosis.2 However, psychotic symptoms in BPD are more varied and frequent than what DSM-5 criteria suggests.

The prevalence of psychotic symptoms in patients with BPD has been estimated between 20% to 50%.3 There also is evidence of frequent auditory and visual hallucinations in patients with BPD, and a recent study using structured psychiatric interviews demonstrated that most BPD patients report at least 1 symptom of psychosis.4 Considering that psychiatric comorbidities are the rule rather than the exception in BPD, the presence of psychotic symptoms further complicates the diagnostic picture. Recognizing the symptoms of BPD is essential for understanding the course of the symptoms and predicting response to treatment.5

Treatment of BPD is strikingly different than that of a primary psychotic disorder. There is some evidence that low-dosage antipsychotics could ease mood instability and perceptual disturbances in patients with BPD.6 Antipsychotic dosages used to treat hallucinations and delusions in a primary psychotic disorder are unlikely to be as effective for a patient with BPD, and are associated with significant adverse effects. Furthermore, these adverse effects—such as weight gain, hyperlipidemia, and diabetes—could become new sources of distress. Clinicians also might miss an opportunity to engage a BPD patient in psychotherapy if the focus is on the anticipated effect of a medication. The mainstay treatment of BPD is an evidence-based psychotherapy, such as dialectical behavioral therapy, transference-focused psychotherapy, mentalization-based therapy, or good psychiatric management.7