Causes of Depression


Depression, More Nature than Nurture?

Typical factors in the development of depression include visible, physical changes in the brain, and measurable changes in the chemicals (i.e., neurotransmitters and hormones) that control brain function. There also appears to be a genetic component to depression, according to Jonathan Flint, whose research into depression has clearly identified one gene that codes for an enzyme essential to mitochondrial function, and another called SIRT1. In contrast, many researchers have identified early-life trauma or hardship as leading to major depressive disorders.

Causes of Depression in Teens

Teen depression may often be the result of feeling helpless to understand or resolve problems. Some of this is nature, because cognitive abilities almost always lag behind brain (psychosocial) development. At the same time, parents and/or, medical and educational professionals may lack the time to address individual depressive symptoms before problems arise. Add to this the rapid hormonal and physical changes that occur, and the fact that teens’ bodies mature much sooner than their brains, and you have a situation that almost predicts teenage depression.

Throw in the increasing turbulence of society worldwide, and the lack of depressive feelings among some teens may be the most surprising development.

Causes of Depression in Adults

In addition to feelings that society is no longer manageable – a feeling adults share with teens – grownups face their own unique set of depressive triggers. These include:

• Biological chemistry, as when neurotransmitters (naturally occurring brain/mood chemicals) and/or hormones become out of balance due to aging or environmental impacts (think “midlife crisis” and “male menopause”).

• Early childhood trauma, whose ultimate effects on behavior are not fully manifest until early middle age, can result in depression.

• Gender; women are almost twice as likely to experience depression in the years between maturity and menopause, but not all the “triggers” are hormonal and feelings of success are failure are often involved in depression. This latter is true in men only after about the fourth or fifth decade.

• Stressful events like a divorce, losing a job or failing to get a promotion, marital problems, or the death of a loved one or friend, can trigger major depressive episodes.

• Medications, prescribed for the kinds of health conditions that arise in middle age, may cause a physical imbalance that results in depression. These “depressive” medications include oral contraceptives, high blood pressure medications, and statins (to control high cholesterol)

Causes of Depression in the Elderly

At an age when most social problems have been resolved – when life becomes, in essence, a waiting game, depression usually has very specific causes. These include retirement, the death of a spouse, medical problems, and increased isolation as aging limits the ability to engage in certain activities.

Because old age can also be a time of great stability – children reared and out of the home, pension assured, home paid for, the meaning of life grasped in large part – depression among the elderly is often as simple as failing health. Health professionals often find that the resolution to depressive episodes is as simple as encouraging a manageable hobby (i.e., painting instead of parasailing). Friends and family can support this effort by helping depressed older adults find an absorbing interest. This can sometimes be as simple as a new pet, or as complicated as arranging living conditions in an extended-care facility that provides greater human contact and more opportunities to feel useful.

Curr Biol. 2015 May 4;25(9):1146-56. doi: 10.1016/j.cub.2015.03.008. Epub 2015 Apr 23.