| Week 1 (if initial exercise completed together with the interventionist rather than independently): |
| (i) Provision and review of treatment manual |
| (ii) Discussion of rationale for PP intervention and potential health benefits |
| (iii) Introduction of initial exercise (Gratitude for Positive Events) |
| (iv) Rating of optimism/positive affect |
| (v) Completion of exercise, and recording of exercise and its effects in the manual |
| (vi) Rating of optimism/positive affect and ease/utility of exercise post-completion |
| (vii) Review of exercise with study trainer |
| (viii) Assignment of second exercise (Personal Strengths) |
| Week 2: |
| (i) Participant independently completes tasks prior to phone session |
| (a) Rating of optimism/positive affect immediately pre-completion |
| (b) Completion of exercise and recording of details/effects |
| (c) Ratings of optimism/positive affect, along with ease/utility of exercise |
| (ii) Phone session with interventionists |
| (a) Review of exercise with study trainer |
| (b) Discussion of adapting skills to daily life, recording favorite skills |
| (c) Assignment of third exercise (Gratitude Letter) |
| Weeks 3-4: |
| (i) Weekly exercise completion (independently) |
| (ii) Weekly phone sessions (for review, skill building, and assignment of next exercise) |
| Weeks 6–10: |
| (i) Bi-weekly exercises |
| (a) Weeks 8 and 10 can be choice from prior exercises and/or Acts of Kindness |
| (ii) Bi-weekly phone sessions |
| Week 12: |
| (i) Review of final exercise |
| (ii) Discussion of skills implementation into daily life with completion of 4-week plan |
