Depression and comorbid panic in primary care patients

Background: Comorbid panic symptoms may complicate depression treatment. However, most research focuses on specialty care, and the evidence in primary care is mixed. Methods: We analyzed data from a randomized trial investigating Selective Serotonin Reuptake Inhibitor (SSRI) Treatment, a longitudinal effectiveness study comparing 3 SSRIs for the treatment of depression in primary care (n = 573). Depression at month 6 was measured using the Symptom Checklist-20; remission was defined as a score <= 0.5; partial response was defined as >= 50% improvement but not to a level of <= 0.5. Nonresponse, the referent level for all analyses, was defined as patients who do not meet either of these criteria. Panic symptoms (yes/no) were measured using a screening question. Results: Rates of remission vs. nonresponse [OR = 1.06 (95% confidence interval 0.67, 1.67)] or partial response vs. nonresponse [OR = 0.92 (95% Cl 0.54, 1.57)] were similar among patients with baseline panic symptoms, adjusting for baseline depression severity. However, patients with persistent panic symptoms were less likely to experience remission (OR = 0.38, 95% CI 0.18, 0.81), while the lower likelihood of partial response did not achieve statistical significance (0.66, 95% CI 0.33, 1.33). Results were similar using complete case, last observation carried forward, and multiple imputation methods, and were robust to varying the sensitivity and specificity of the panic screening question. Conclusion: Panic symptoms that persist are associated with worse depression outcomes in the maintenance phase. Consequently, improvement in panic symptoms may be important for improved depression outcomes and primary care physicians should be attuned to the presence of panic symptoms when making treatment decisions. (C) 2009 Elsevier B.V. All rights reserved.