Long-Term Management of Major Depressive Disorder: Are Differences Among Antidepressant Treatments Meaningful?

Recurrent depression poses a problem for up to 80% of patients with major depressive disorder(MDD) during their lifetime. Therefore, the optimal treatment goal established by the American PsychiatricAssociation and the Agency for Health Care Policy and Research is remission and virtualelimination of symptoms. Patients who have a high risk of recurrence often require maintenancetherapy and long-term treatment. As a result, identification of antidepressants that are effective inmaintaining remission in patients over the long-term and have acceptable tolerability profiles is important.The efficacy of antidepressants in conferring full remission and long-term recovery is an importantpriority for clinicians. Both selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrinereuptake inhibitors (SNRIs) have been examined for use in long-term treatment ofMDD. Recently, 2 long-term (6 to 12 months), double-blind, placebo-controlled studies have shownthat venlafaxine is effective in preventing relapse and recurrence. While long-term, head-to-headstudies comparing SNRIs with SSRIs are rare, a recent open-label study compared venlafaxine to 4SSRIs (fluoxetine, paroxetine, sertraline, or citalopram) in outpatients with MDD. The results showthat the SNRI venlafaxine is comparable to the SSRIs in terms of remission rates, and venlafaxinemay bring patients to remission earlier than SSRIs. Long-term treatment at maximally tolerated dosesis also associated with similar incidence of common adverse events between venlafaxine and placeboand tolerability comparable to SSRIs. Thus, there is increasing evidence that venlafaxine and SSRIsare effective and well tolerated in long-term therapy. While it is unclear from the data if continuedtreatment with SNRIs confers advantages over SSRIs due to an early onset of remission, further studieswill provide valuable insights into the efficacy of SNRIs and SSRIs in maintenance therapy.