Impact of comorbid anxiety disorders and obsessive-compulsive disorder on 24-month clinical outcomes of bipolar I disorder.

BACKGROUND: This study investigated the impact of comorbid obsessive-compulsive disorder (OCD) and four anxiety disorders [panic disorder (PD), agoraphobia, social anxiety disorder (SAD), and generalized anxiety disorder (GAD)] on the clinical outcomes of bipolar disorder.

METHODS: This study analysed data of 174 patients with bipolar I disorder who participated in the prospective observational study. Participants were assessed every 3 months for 24 months. The primary outcome measure was the achievement of symptomatic remission, defined by a total score on the Young Mania Rating Scale (YMRS) of ≤12 and a total score on the 21-item Hamilton Depression Rating Scale (HAMD-21) of ≤8.

RESULTS: Comorbidity was associated with decreased likelihood of remission. However, the impact of individual disorders on outcome differed according to clinical and treatment situations. Most comorbid anxiety disorders and OCD had a negative effect on remission during the first year of evaluation, as measured by the HAMD-21, and in patients taking a conventional mood stabilizer alone. However, the association with poorer outcome was observed only for a few specific comorbid disorders in the second year (GAD and OCD), as measured by YMRS-defined remission (OCD), and in patients with olanzapine therapy (GAD and OCD).

LIMITATIONS: Follow-up evaluation of comorbid disorders was lacking.

CONCLUSIONS: Comorbid anxiety disorders and OCD negatively influenced the clinical course of bipolar disorder. Specifically, OCD had a consistently negative impact on the outcome of bipolar I disorder regardless of clinical situation. Effective strategies for the control of these comorbidities are required to achieve better treatment outcomes.