Combinations of stressors in midlife: examining role and domain stressors using regression trees and random forests.

Objectives: Global perceptions of stress (GPS) have major implications for mental and physical health, and stress in midlife may influence adaptation in later life. Thus, it is important to determine the unique and interactive effects of diverse influences of role stress (at work or in personal relationships), loneliness, life events, time pressure, caregiving, finances, discrimination, and neighborhood circumstances on these GPS.

Method: Exploratory regression trees and random forests were used to examine complex interactions among myriad events and chronic stressors in middle-aged participants' (N = 410; mean age = 52.12) GPS.

Results: Different role and domain stressors were influential at high and low levels of loneliness. Varied combinations of these stressors resulting in similar levels of perceived stress are also outlined as examples of equifinality. Loneliness emerged as an important predictor across trees.

Discussion: Exploring multiple stressors simultaneously provides insights into the diversity of stressor combinations across individuals--even those with similar levels of global perceived stress--and answers theoretical mandates to better understand the influence of stress by sampling from many domain and role stressors. Further, the unique influences of each predictor relative to the others inform theory and applied work. Finally, examples of equifinality and multifinality call for targeted interventions.