Factors associated with the persistence and onset of new anxiety disorders in youth with bipolar spectrum disorders.

Objective: Anxiety disorders are among the most common comorbid conditions in youth with bipolar disorder, but, to our knowledge, no studies examined the course of anxiety disorders in youth and adults with bipolar disorder.

Method: As part of the Course and Outcome of Bipolar Youth study, 413 youth, ages 7 to 17 years who met criteria for Diagnostic and Statistical Manual, Fourth Edition (DSM-IV) bipolar I disorder (n = 244), bipolar II disorder (n = 28), and operationally defined bipolar disorder not otherwise specified (n = 141) were recruited primarily from outpatient clinics. Subjects were followed on average for 5 years using the Longitudinal Interval Follow-Up Evaluation. We examined factors associated with the persistence (> 50% of the follow-up time) and onset of new anxiety disorders in youth with bipolar disorder.

Results: Of the 170 youth who had anxiety at intake, 80.6% had an anxiety disorder at any time during the follow-up. Most of the anxiety disorders during the follow-up were of the same type as those present at intake. About 50% of the youth had persistent anxiety, particularly generalized anxiety disorder (GAD). Persistence was associated with multiple anxiety disorders, less follow-up time in euthymia, less conduct disorder, and less treatment with antimanic and antidepressant medications (all P values ≤ .05). Twenty-five percent of the sample who did not have an anxiety disorder at intake developed new anxiety disorders during follow-up, most commonly GAD. The onset of new anxiety disorders was significantly associated with being female, lower socioeconomic status, presence of attention-deficit/hyperactivity disorder and substance use disorder, and more follow-up time with manic or hypomanic symptoms (all P values ≤ .05)

Conclusions: Anxiety disorders in youth with bipolar disorder tend to persist, and new-onset anxiety disorders developed in a substantial proportion of the sample. Early identification of factors associated with the persistence and onset of new anxiety disorders may enable the development of strategies for treatment and prevention.