Initiating and Maintaining Physical Activity in Depressed Individuals

The investigators propose a randomized clinical trial in which 240 depressed individuals are
assigned to one of three arms, with each successive arm having an added component that may
serve to increase and maintain physical activity:

1. brief advice (BA) to exercise (control condition);

2. BA + supervised & home-based exercise (SHE)+health education (HE) contact control; and

3. BA+SHE+ cognitive-behavioral sessions focused on increasing and maintaining exercise
(CBEX).

There are two phases for participants: intervention phase (3 months), which consists of
intensive contact, and the follow-up phase (6 months). BA will consist of one, 45-minute
session about public health recommendations, and strategies for getting started. SHE will be
a 12-week intervention consisting of 1x/week supervised exercise plus exercise prescriptions
for home-based exercise with the goal of gradually achieving the public health recommendation
of 150 minutes/week of moderate-to-vigorous physical activity (MVPA), CBEX and HE sessions
will be individual, 30-minute, weekly sessions during the intervention phase. CBEX will
address barriers to physical activity that are particularly pronounced in depression -i.e.,
anhedonia, decreased motivation, and decreased energy, as well as poor problem-solving
skills. During the follow-up phase, groups who received SHE during the intervention phase
will receive brief, monthly phone check-ins from an exercise specialist.

Primary Aims:

1. To compare the efficacy of the 3 arms for increasing physical activity during the
12-week intervention phase. We hypothesize that BA + SHE + CBEX will be superior to BA +
SHE + HE, and that BA + SHE + HE will be superior to BA alone in terms of objectively
measured MVPA levels.

2. To compare the longer-term impact of the three arms on objectively-measured minutes of
MVPA at 6- and 9-month follow-ups (i.e., follow-up phase). Hypotheses are the same as
for the intervention phase (aim #1).

Secondary Aims:

3. To assess the impact of proposed intervention combinations on depression, physical
health outcomes including cardiorespiratory fitness and body composition, and
self-reported MVPA in all phases. Hypotheses mirror those described in our primary aims
above.

4. To determine whether amount of MVPA mediates the association between group assignment
and change in depressive symptoms. We hypothesize that amount of MVPA will serve as a
mediator.

5. To examine behavior change theory-based mediators of the association between group
assignment and MVPA. Hypothesized mediators include: perceived benefits of exercise,
perceived barriers to exercise, exercise self-efficacy, intrinsic motivation to
exercise, and identified motivation to exercise.

6. To examine whether social and environmental barriers to exercise predict exercise
maintenance.

Inclusion Criteria:

1. Sedentary, i.e., have not participated regularly in moderate-to-vigorous physical
activity (MVPA) for 90 minutes per week or more for the past 12 weeks.

2. Medically cleared for MVPA, documented by a note from their primary care provider.

3. No significant medical condition or physical disability that would interfere with
physical activity or study participation. The investigators will exclude individuals
with significant cardiovascular disease, hematologic disorders, and autoimmune
disorders. The investigators will also exclude individuals who are planning a surgery
in the next 9 months and those with dementia.

4. Elevated depression symptoms. To meet criteria for elevated symptoms, participants
must have a QIDS score of 10 or greater (i.e., at least moderate depression levels),
and must have a score of "1" or greater on at least one of the two core DSM-V
depressive symptoms, i.e., sad mood or anhedonia. -

5. No current bulimia or anorexia (past 3 months); no history of bipolar disorder,
schizophrenia, or a chronic psychotic condition (assessed using the SCID).

6. No hazardous drug or alcohol use in the past 6 months, as assessed by: a. no substance
abuse treatment in the past 6 months; and b. does not meet criteria for a substance
use disorder in the past 6 months.

7. Depression is not very severe, i.e., QIDS score is < 20.

8. No suicidality requiring immediate treatment.

9. Not pregnant or planning on becoming pregnant in the next year.

10. Understands English sufficiently well to consent and complete study assessments.

11. Aged 18-65.

12. Able to make one of the 2 available exercise class times.

13. Able to walk 1 mile