+ theory proposes that it is the big issues, like death of a loved one or marriage, that lead to the most stress in our lives.

Biosocial Theory

Explanation:

Biosocial Theory may be defined as a theory where behavioral as well as social science which describes the personality disorders and mental disabilities and illnesses like stress as a biologically-determined personality traits that reacts to the environmental stimuli.

This theory supports that some issues like the death of a love person or marriages may lead us to some mental disorders or stress in our lives.