"Engage" Therapy: Behavioral Activation and Improvement of Late-Life Major Depression.

Objective: Engage is a treatment for late-life depression developed to match the skills of community clinicians based on the theory that dysfunction in the Research Domain Criteria Project positive valence systems is a critical mechanism of late-life depression. Accordingly, it uses "reward exposure" (engagement in meaningful, rewarding activities) as its principal intervention. This study tests the hypothesis that change in behavioral activation, an index of positive valence systems function, during successive treatment periods with Engage and during follow-up predicts depression at the end of each period.

Methods: Forty-eight nondemented, older adults with unipolar major depression were treated openly with 9 weekly sessions of Engage and assessed 36 weeks after entry. Depression severity was assessed with the 24-item Hamilton Depression Rating Scale (HAM-D) and behavioral activation with the Behavioral Activation for Depression Scale (BADS) at baseline, 6 weeks (mid-treatment), 9 weeks (end of treatment), and 36 weeks.

Results: A mixed-effects model examined whether change in BADS in successive periods occurring during Engage treatment and during follow-up predicts depression at the end of each period. Both BADS change (F1,52 = 18.63, p < 0.0001) and time (F2,52 = 7.68, p = 0.0012) predicted HAM-D scores at the end of each observation period. Every point of increase in BADS change reduced the HAM-D by 0.105 points. HAM-D at each point did not predict subsequent change in BADS (F1,52 = 2.17, p = 0.146).

Conclusion: During Engage treatment and follow-up, change in behavioral activation is followed by improvement of depressive symptoms and signs.