Stress in general can contribute to depression in persons biologically vulnerable to the illness. Some have theorized that higher incidence of depression in women is not due to greater vulnerability, but to the particular stresses that many women face. These stresses include major responsibilities at home and work, single parenthood, and caring for children and aging parents. How these factors may uniquely affect women is not yet fully understood.

For both women and men, rates of major depression are highest among the separated and divorced, and lowest among the married, while remaining always higher for women than for men. The quality of a marriage, however, may contribute significantly to depression. Lack of an intimate, confiding relationship, as well as overt marital disputes, have been shown to be related to depression in women. In fact, rates of depression were shown to be highest among unhappily married women.