Differential patterns of lifetime multiple anxiety disorder comorbidity between Latino adults with bipolar I and major depressive disorders.

Background: To determine the lifetime rates of panic disorder, obsessive-compulsive disorder (OCD), social phobia, and posttraumatic stress disorder (PTSD) among adult Latino patients with major depressive disorder (MDD) and bipolar disorder (BPD), and whether there are dose-response relationships between loading for comorbid anxiety disorders, the probability of having BPD, and attributes of severity of illness.

Methods: In a public sector clinic for the indigent located in a semiclosed rural community, 187 consecutively presenting affectively ill Latino patients were evaluated by use of the Structured Clinical Interview for DSM-IV. Polarity and the lifetime prevalence of panic disorder, OCD, social phobia, and PTSD were determined. Logistic regression was used to test associations. Trends in positive predictive values (PPVs) and likelihood ratios were assessed to determine whether dose-response relationships existed between loading for comorbid anxiety disorders and the likelihood of having BPD as opposed to MDD, psychosis, suicidal ideation, and suicide attempts.

Results: Of 187 subjects, 118 (63.1%) had MDD and 69 (36.9%) had BPD. The odds ratio of a patient with BPD, relative to MDD, of having panic disorder was 4.6 (p< .0001), OCD 7.6 (p< .0001), social phobia 6.0 (p< .0001) and PTSD 5.3 (p< .0001). The PPV of having BPD was 91.3% and of having psychotic features 83.0% if one had all four anxiety disorders. There was a dose-response relationship between loading for comorbid anxiety disorders and the likelihood of having had a suicide attempt (but not suicidal ideation).

Conclusions: As previously reported by us for juvenile patients, Latino adults with BPD had a remarkably high risk of having each anxiety disorder relative to patients with MDD. The results indicate that the risk of having BPD, having a psychosis, and making a suicide attempt becomes increasingly great as the number of comorbid anxiety disorders increases. These data, which are consistent with the notion of anxious bipolarity, provide further support for a possible anxious diathesis in bipolar disorder.