Duration of relapse prevention after cognitive therapy in residual depression: follow-up of controlled trial

BACKGROUND: Although there is good evidence that cognitive therapy (CBT) lessens relapse and recurrence in unipolar depression, the duration of this effect is not known. METHOD: One hundred and fifty-eight subjects, from a randomized controlled trial of CBT plus medication and clinical management versus medication and clinical management alone, were followed 6 years after randomization (4 1/2 years after completion of CBT) and the longitudinal course assessed. RESULTS: Effects in prevention of relapse and recurrence were found to persist, with weakening, and were not fully lost until 3 1/2 years after the end of CBT. Residual symptoms were also lessened. CONCLUSIONS: The effect of CBT in reduction of relapse and recurrence persists for several years. The potential value of subsequent additional CBT some time after cessation should be explored.