Sudden gains in cognitive-behavior therapy for treatment-resistant depression: Processes of change.

OBJECTIVE: Sudden gains were investigated in cognitive-behavioral therapy (CBT) for treatment-resistant depression (TRD). Client and therapist processes in sessions proximal to sudden gains were examined to better understand the antecedents of sudden gains and potential mechanisms linking them to outcome. METHOD: Participants were 156 adults with TRD in a randomized controlled trial of CBT as an adjunct to pharmacotherapy (Wiles et al., 2013). Depression symptoms were assessed by the Beck Depression Inventory-II at each session. In a subsample of 50 clients, audio-recordings of 125 therapy sessions were rated for hope, emotional processing, and therapist competence in case-conceptualization. RESULTS: Sudden gains were experienced by 54% of participants. Those with gains reported significantly lower depression severity at 12-month follow-up and more remission of symptoms than those without gains. Sudden gains also predicted lower depression at follow-up, beyond the slope of linear change in symptoms across treatment. Therapists demonstrated greater competence in case conceptualization with clients who reported sudden gains, and those with gains expressed more hope in sessions prior to a gain. In addition, more hope and emotional processing in the pregain sessions predicted less depression at follow-up, controlling for depression scores in the prior session. Better therapist conceptualization skills and more client hope in the baseline and pregain sessions were also associated with more emotional processing in those same sessions. CONCLUSION: This study extends the phenomenon of sudden gains in CBT for depression to a treatment-resistant population and identified important therapy processes that predicted long-term outcomes: hope and emotional processing. (PsycINFO Database Record