Time to Rehospitalization in Patients With Major Depressive Disorder Taking Venlafaxine or Fluoxetine

Objective: The combined serotonin-norepinephrine reuptake inhibitor, venlafaxine, has demonstrated better short-term efficacy than selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine in pooled analyses. This study aimed to compare venlafaxine and fluoxetine treatment in the long-term outcome measure, time to rehospitalization, in patients with major depressive disorder. Other clinical factors that may influence time to rehospitalization were also explored.

Method: Han Chinese patients were admitted to the depression inpatient unit of a major psychiatric center in Taiwan from January 1, 2002, to December 31, 2003. Patients with major depressive disorder (DSM-IV) who showed favorable treatment response to venlafaxine (mean ± SD dose = 116.5 ± 42.5 mg/day; N = 122) or fluoxetine (mean ± SD dose =25.1 ± 9.0 mg/day; N = 80) during hospitalization were followed up for 1 year after discharge under naturalistic conditions. The 2 treatment groups were similar in demographic and clinical characteristics: sex, age, age at illness onset, comorbid anxiety disorders, personality disorders, nicotine dependence, psychotic features, adjunctive antipsychotics use, duration of index hospitalization, and number of previous hospitalizations. Time to rehospitalization was measured by the Kaplan-Meier method. Possible associations of rehospitalization with other covariates were analyzed using the Cox proportional hazards regression model.

Results: No significant difference for the time to rehospitalization was found between the 2 groups by the log-rank test. The number of previous admissions (hazard ratio = 1.331, 95% CI = 1.153 to 1.538, p = .000), but not other factors, increased the risk of rehospitalization.

Conclusion: The findings suggest that venlafaxine and fluoxetine have similar effects on time to rehospitalization in patients with major depressive disorder. The relatively low dose of venlafaxine may have contributed to the negative finding. Previous hospitalization history may raise the risk of rehospitalization. Longer-term, double-blind, randomized, fixed-dose studies are warranted to better delineate the effectiveness of different pharmacotherapeutic regimens for the outcomes of patients with major depressive disorder.