Efficacy of Adjunctive Exercise for the Behavioral Treatment of Major Depression

Behavioral Activation Therapy (BA). All participants will receive a standard behavioral activation treatment based on the manualized treatment described by Lejuez et al., 2011. Treatment will be delivered in 60-minute weekly sessions over a 6-week period followed by 3 biweekly booster sessions. Behavioral activation includes scheduling activities the patient will enjoy and find important with the purpose of improving mood.

Exercise Intervention (EX). The exercise intervention will immediately follow each of the first six weekly BA sessions. Each EX session will comprise 30 minutes of either providing rationale for the program or reviewing the previous week's progress. As part of the intervention, participants will be asked to perform 40 minutes of aerobic exercise at 60-75% of maximum heart rate on three days each week, with 5 minute stretching warm up and cool down. We will help all participants initiate and plan their at-home program of exercise.

Stretching Intervention (STR). The stretching intervention will also follow each of the first six weekly BA sessions. These sessions will comprise 30 minutes of providing rationale for the stretching program or reviewing the previous week's progress. As part of the intervention, participants will be asked to perform 50 minutes of stretching on three days each week. Participants in this condition will be provided with a 50-minute DVD of stretching exercises and will work with the therapist to plan their at-home stretching exercises.