There are multiple factors that contribute to causing depression. However, very often, the first time a person experiences depression, it is during or following a stressful life event such as a breakup, move or job loss. In some cases, if a person’s depressed mood is primarily due to a life stressor, and the mood improves as the begins to resolve itself, that person may be diagnosed with something called an Adjustment Disorder, rather than a depressive disorder. Adjustment Disorder implies that a person is having a difficult time coping with a specific stressor or stressors and that distress will decrease and no longer interfere with daily life once a person gets used to the new situation.
However, when the depressed mood persists over time or when lots of little things add up to create high stress, it may be associated with depression. Some researchers have speculated the association with life stress is because depressive symptoms result from an overreaction of the body’s stress response. Is also appears that some people are biologically prone to depression, but that even those who are biologically-prone may not experience depression until a stressful life event occurs. Interestingly, the association between life stress and depression becomes weaker as a person experiences more periods of depression.
What Kinds of Life Stressors Are Associated with Depression?
When people think of big stressors, they usually think of things like the breakup of a relationship, losing a job, or the death of a loved one. Indeed, these types of events commonly precede the first experience of depression. However, any kind of major life change, even if it is desired, can be experienced as stressful. Thus, events that people typically think of as “positive” events, such as going off to college, getting married, the birth of a child or a job promotion can also be experienced as very stressful and are sometimes associated with symptoms of depression.
Another type of stress – the pile up of daily hassles – can also be associated with feeling depressed. Daily hassles are things all people have to deal with in their daily lives that create some amount of stress. For example, hassles might include things like paying bills, home and auto repairs, getting a cold, and routine disagreements with friends or family. When the daily hassles of life pile up, people may begin to feel overwhelmed. It is a bit tricky to say if a pile up of such hassles can cause depression, because people may be more likely to perceive everyday tasks as hassles, and to let them pile up, when they are feeling depressed. However, there is an association between daily hassles and depressed mood. The association may be somewhat more common among people with Persistent Depressive Disorder type of depression than other types (Ravindran, Griffiths, Waddell, & Anisman, 1995).
Does Depression Usually Occur Following Increased Stress?
No. Although being depressed is typically experienced as quite stressful in itself, and major depression often occurs for the first time following a major life stressor, life stress does not always occur before someone becomes depressed. In fact, the strength of the association between depression and life stress decreases as people experience a greater number of depressive episodes. For example, if someone is experiencing a 3rd or 4th depressive episode, there may be relatively little change in life stress prior to the occurrence of that episode. One of the theories to explain why stress becomes less associated with depression over time is that the very experience of being depressed changes the brain in ways that makes is more prone to depression in the future. This theory is sometimes referred to as the “kindling hypothesis” (Monroe & Harkness, 2005). There is some support for this idea because depression is associated with certain changes in the brain.
Monroe, S. M., & Harkness, K. L. (2005). Life stress, the "kindling" hypothesis, and the recurrence of depression: considerations from a life stress perspective. Psychol Rev, 112(2), 417-445. doi:10.1037/0033-295x.112.2.417
Ravindran, A. V., Griffiths, J., Waddell, C., & Anisman, H. (1995). Stressful life events and coping styles in relation to dysthymia and major depressive disorder: variations associated with alleviation of symptoms following pharmacotherapy. Prog Neuropsychopharmacol Biol Psychiatry, 19(4), 637-653.