Bipolar disorder, borderline development or trauma-related dysregulation? A complex adolescent case with recurrent hospitalizations

Introduction

Affective instability, impulsivity, and self-injurious behaviors in adolescence pose significant diagnostic challenges. Clinical presentations frequently overlap across mood disorders, emerging personality pathology, and trauma-related conditions.

Current evidence supports a partially overlapping spectrum of affective dysregulation, in which bipolar disorder (BD) and borderline personality disorder (BPD) share vulnerability factors—particularly early-life adversity—while remaining distinguishable by their longitudinal course. Trauma-related alterations in emotional regulation and stress responsivity further complicate diagnostic boundaries in adolescent populations.

Objectives

To present a clinically complex adolescent case with repeated hospitalizations, emotional dysregulation, and substance use, and to examine the diagnostic uncertainty between bipolar disorder, borderline personality development, and trauma-related pathology.

Methods

We report the case of a 16-year-old girl with multiple admissions to a child and adolescent psychiatry unit. Clinical data were reviewed retrospectively, including developmental history, psychiatric assessments, and toxicology findings, focusing on symptom evolution and diagnostic hypotheses across admissions.

Results

The patient was repeatedly admitted for suicidal ideation, self-injury, and marked emotional instability, often associated with impulsivity and substance use. Her history included parental substance abuse, neglect, exposure to domestic violence, and prolonged sexual abuse during early adolescence.

Symptoms began at about 10 years of age with depressive symptoms and self-harm, followed by a progressively complex clinical course including repeated suicide attempts, substance use and multiple hospitalizations. The clinical picture over time took on a fluctuating pattern of depressive episodes, emotional lability, irritability and impulsivity.

Episodes indicative of mood elevation, e.g. reduced need for sleep, increased activity and logorrhea, and also grandiosity, were also recorded, but often were temporally related to psychosocial stressors or substance use, raising questions about their diagnostic import in a bipolar spectrum.

Toxicology screens were intermittently positive for stimulants and cannabis. Psychotic-like symptoms, when present, were brief and occurred only during substance use or acute distress.

Treatment varied across admissions. She received fluoxetine, quetiapine, olanzapine, and at one stage topiramate, targeting mood instability and impulsivity. There was no consistent use of a mood stabilizer, and treatment followed a symptom-based approach. Clinical response was variable, often partial.

Over time, several diagnoses were considered, including bipolar disorder, cyclothymia, trauma-related disorder, dissociative symptoms, and borderline personality traits.

Conclusion

In this case, applying a single diagnosis proved difficult. While some features suggested bipolarity, the overall longitudinal picture — particularly the role of trauma and symptom variability — points toward a more complex emotional dysregulation.

The treatment course reflects this uncertainty, favoring symptom management over a fixed diagnostic framework. Longitudinal assessment and a trauma-informed approach remain essential, alongside psychotherapy.

This case highlights the limitations of rigid diagnostic boundaries in adolescent psychiatry, particularly in patients with cumulative adverse experiences. It underscores the significant clinical overlap between bipolar disorder and emerging borderline personality pathology, especially in the domain of affective instability, impulsivity, and interpersonal dysfunction. Within this context, a longitudinal, dimensional, and trauma-informed approach becomes essential, prioritizing clinical evolution over premature diagnostic labeling. Such an approach allows for a more nuanced differentiation between episodic mood dysregulation suggestive of bipolarity and the more pervasive, context-dependent patterns characteristic of borderline development, while acknowledging that these dimensions may coexist and interact over time.

References

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