Preventing relapse in recurrent depression using new forms of cognitive therapy: A randomized controlled trial with up to 6 years follow-up

Introduction Since major depressive disorder is a recurrent disorder, a shift from cure (during the symptomatic phase) to prevention is necessary (Judd, 1997, Scott, 2006). Sequential treatment in which CT (or Mindfulness based cognitive therapy, MBCT) is started after antidepressant treatment remission (Teasdale et al., 2000, Ma and Teasdale, 2004) or after a variety of acute treatments (Bockting et al., 2005), appears to be an effective strategy to prevent recurrence in patients at high-risk for recurrence. We aimed to study enduring effects up to six years of a randomized controlled trial of cognitive therapy (CT) to prevent relapse/recurrence in a group of high risk patients diagnosed with recurrent depression. Methods Depressed patients with ≥ 2 episodes, currently in remission following various types of treatment (n = 187) were randomized to treatment as usual (TAU), including continuation of pharmacotherapy, or to TAU with additional brief CT. Recurrence of a new depressive episode was assessed during follow-up over six years. Results Adding CT to TAU resulted in a significant protective effect which was amplified when patients had experienced more depressive episodes previously. For patients with five or more previous episodes (41% of the sample), CT reduced relapse/recurrence from 72% to 46% at the 2 year follow-up wave. This reduction in relapse in the group who received initially 8 weeks of CT still exists after almost six years (p < 0.01, difference of proportion of relapse: 24.9% in patients with ≥ 4 prior episodes; medium effect size). Discussion Our findings extend the accumulating evidence that cognitive interventions following remission can be useful in preventing relapse/recurrence and have enduring effects over almost six years in patients with recurrent depression.