Anxiety disorders anticipate the diagnosis of bipolar disorder in comorbid patients: Findings from an Italian tertiary clinic

Background: Studies indicate bipolar disorder (BD) syndromal symptoms are commonly preceded by sub-syndromal BD symptoms, dysregulated sleep, irritability, and anxiety. We aimed to evaluate prevalence and clinical correlates of anxiety disorders (ADs) at BD onset in outpatients with versus without at least one AD at BD onset. Methods: 246 bipolar spectrum outpatients, according to the text revision of the fourth edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM- IV-TR), attending Sacco University Hospital in Milan, were recruited and their onset and clinical features assessed retrospectively. Patients were stratified into those with versus without an AD at BD onset (w/A and wo/A), according to a semi-structured clinical interview to provide diagnoses according to (DSM- IV-TR). Results: 29% of patients reported being w/A, among whom Panic Disorder (PD, in 55.6%) was the most frequent AD, and first AD occurred approximately 4 years before BD diagnosis. Patients w/A versus wo/A had higher (p < 0.05) rates of BDII and first mood episode being depression versus elevation (mania/hypomania), and lifetime rates of separation anxiety disorder, substance poly-abuse and benzodiazepine abuse. In contrast, patients wo/A had higher lifetime rates of alcohol and illicit drug use. Conclusion: In this naturalistic sample, ADs, in particular PD, preceded BD in almost 1/3 of BD outpatients, and had distinctive clinical correlates. Further investigation into relationships between BD and AD at onset may enhance early BD diagnosis and treatment.