Distinguishing between psychotic disorders and borderline personality disorder (BPD) remains one of the most persistent challenges in psychiatry. Clinicians often observe overlapping symptoms, including emotional dysregulation and psychotic experiences, yet these disorders are still treated as distinct and sometimes mutually exclusive diagnoses.
Despite this distinction, the actual prevalence and clinical implications of their co-occurrence have not been clearly quantified. To address this knowledge gap, Julie Jourdan, a neuropsychologist and PhD candidate in neuropsychology and psychopathology, and colleagues developed a systematic review and meta-analysis to provide reliable epidemiological estimates and better characterize this patient subgroup, which is frequently encountered in clinical settings but has been insufficiently studied. The results of the review and analysis were published in Psychological Medicine.
Jourdan spoke with Physician’s Weekly about their findings.
Physician’s Weekly: How can the co-occurrence of psychotic disorders and BPD complicate clinical management?
Jourdan: Comorbidity significantly increases clinical complexity. Patients typically present with more severe symptom profiles, including greater emotional dysregulation, suicidal tendencies, and more intense psychotic symptoms. From a practical standpoint, this poses several challenges: diagnostic uncertainty, fragmented care pathways, and difficulty determining treatment priorities (ie, emotional stabilization vs management of psychosis). This often results in inconsistent care, delayed interventions, and poorer outcomes.
How can categorical management of psychiatric disorders be detrimental to optimal patient care?
Categorical approaches can obscure the reality of clinical manifestations. In practice, clinicians may feel compelled to choose between different diagnoses, which can lead to the underdiagnosis of psychotic symptoms or personality disorders. This has concrete consequences: diagnostic errors or delays, exclusion from specialized services (eg, early psychosis intervention programs), and fragmented treatment strategies. Our findings support a more dimensional and transdiagnostic approach, in which overlapping symptom domains are assessed and treated simultaneously rather than separately.
What are the most important findings from your work?
We have identified a significant bidirectional association between psychotic disorders and BPD:
7% of people with psychotic disorders meet the criteria for BPD.
3% of people with BPD have a psychotic disorder.
In the case of first-episode psychosis, 40% meet the criteria for BPD.
Beyond prevalence, this subgroup is characterized by greater emotional distress, increased suicidality, more pronounced social dysfunction, frequent exposure to trauma, dissociation, and substance use. These results suggest that this is not a marginal phenomenon, but a clinically significant subgroup.
How can these findings be incorporated into practice?
From a clinical perspective, our findings support three main changes:
Systematic screening for BPD traits in psychotic patients (particularly in the early stages) and vice versa
Integrated care models that combine approaches targeting both emotional regulation and psychotic symptoms
Trauma-informed interventions, given the central role played by negative experiences
Programs combining early intervention for psychosis with therapies such as dialectical behavior therapy or mentalization-based treatment appear particularly promising.
What makes this issue particularly urgent in the healthcare landscape?
This issue is urgent because these patients often find themselves “lost” between departments. They may be excluded from early psychosis intervention programs due to a personality disorder or receive inadequate treatment for their psychosis as part of care for personality disorders. This “diagnostic back-and-forth” contributes to delays in treatment, disengagement, and chronicity. At the same time, this population exhibits high levels of suicide risk and functional impairment, making early and appropriate intervention essential.
What would you like future research to be focused on?
Future research should go beyond cross-sectional studies and focus on:
Longitudinal trajectories, to understand how these disorders interact over time
Mechanisms of co-occurrence, particularly trauma, dissociation, and neurocognitive processes, and integrated treatment models evaluated in randomized controlled trials
Dimensional frameworks, to better understand symptom overlap
It is also necessary to employ multi-method approaches, including digital phenotyping and ecological assessments, to better understand symptom dynamics in real-life contexts.
Is there anything else that you feel clinicians would benefit from knowing about your research?
One of the key takeaways is that this co-occurrence should not be viewed as diagnostic confusion, but rather as a distinct and clinically significant phenotype. Recognizing it allows for a more accurate diagnosis, more personalized care, and, ultimately, better outcomes. More generally, our findings support a shift toward a person-centered, dimensional approach to psychiatry, better suited to the complexity of clinical manifestations observed in daily practice.
Contributor
Julie Jourdan
Neuropsychologist
PhD candidate in Neuropsychology and Psychopathology
Centre Hospitalier Universitaire de Nîmes
Nîmes, France
Any views and opinions expressed are those of the author(s) and/or participants and do not necessarily reflect the views, policy, or position of Physician’s Weekly, their employees, and affiliates.