Predictors of symptom resolution in panic disorder after one year of pharmacological treatment: a naturalistic study

OBJECTIVE: In this naturalistic and prospective study, patients with panic disorder (PD) were treated for one year 1) to verify the rate of patients achieving the resolution of full-symptom attacks, limited-symptom attacks, anticipatory anxiety, phobic avoidance and depression; and 2) to identify the predictors of symptom resolution for each domain. METHOD: One hundred patients with PD, according to DSM-IV criteria, participated in the study. In all patients, a baseline and a follow-up with monthly evaluations of SCL-90, Ham-A, Ham-D and panic diaries were carried out over a one-year period. All patients were treated with paroxetine or citalopram. RESULTS: Seventy-one patients completed the study, whereas the remaining 29 dropped out. Among completers, remission of full- and limited-symptom panic attacks was observed in 76 % of patients, whereas complete remission (resolution of panic attacks, anticipatory anxiety, phobic anxiety, and depression) was achieved by only 46 % of patients. Predictors of absence of symptom remissions were obsessive-compulsive disorder (OCD) and recurrent major depression (MD) comorbidity (for panic attacks), pre-treatment severity of anxious symptoms (for anticipatory anxiety), phobic anxiety (for phobic avoidance), and depressive symptoms (for depression). CONCLUSION: This naturalistic study shows that the high comorbidity of OCD and MD and the greater pre-treatment severity of anxious, phobic and depressive symptoms reduced the likelihood of achieving complete remission of symptoms in PD patients who completed the protocol, even though they were adequately treated with SSRI medication.