[Bipolar disorders and comorbid anxiety: prognostic impact and therapeutic challenges]

Anxiety disorders are among the main psychiatric conditions co-occuring with bipolar disorders. Many clinical and epidemiological studies have found much higher prevalence rates of generalized anxiety disorder, social phobia, obsessive-compulsive disorder, panic disorder and post-traumatic stress disorder in bipolar patients than in the general population, regardless of age. In the National Comorbidity Survey for instance, the diagnosis of at least one anxiety disorder was made for nearly 90% of bipolar subjects. Several issues arise from this high comorbidity, such as the way anxiety disorders alter the course and prognosis of the mood disorder, and challenge typical therapeutic strategies. This article reviews data on clinical and therapeutical significance of such comorbidity.

Many studies point out the poorer outcome for bipolar patients with co-occurring anxiety symptoms: apart from the alarming increase of suicidal ideas and suicide attempts, authors have found a shorter duration of euthymia, more comorbid addictions, mixed states and rapid cycling, and lower response to treatments. This is the reason why monitoring the suicidal risk in those bipolar patients with co-occurring anxiety disorders is of critical importance. From a physiopathological standpoint, the precise links between both pathologies remains unclear. The frequency of this comorbidity and its significance on long term prognosis stands in sharp contrast with the very few therapeutic studies conducted in this indication so far. Pharmacological approaches are strongly limited by the risk of mood switching under antidepressants and drug dependence on anxiolytics such as benzodiazepines. Nevertheless, there is emerging evidence of the interest of atypical antipsychotics such as olanzapine and mood stabilisers such as lamotrigine to control anxiety symptoms in bipolar patients. There is weaker evidence for other molecules. Taking into account other therapeutic approaches than the pharmacological approach appears accurate. Psychosocial interventions such as cognitive-behavioral therapies or psychoeducation appear essential to improve in a correct way the global functioning and quality of life of these patients.