Women engaging in transactional sex have disproportional mental health co-morbidity and face substantial barriers to accessing social services. We hypothesized that participation in a longitudinal research study, with no overt intervention, would lead to short-term mental health improvements. For 4-weeks, 24 women disclosed information about their lives via twice daily cell-phone diaries and weekly interviews. We used t tests to compare self-esteem, anxiety, and depression at baseline and exit. Tests were repeated for hypothesized effect modifiers (e.g.,