Answer:
Depression, like many chronic illnesses (such as diabetes or heart disease), tends
to run in families. For most diseases with a heritable component, having a close family
member with the illness does not necessarily mean that one will develop the illness
oneself. Nonetheless, having a close family member with the disease often does confer
an increased likelihood that one will develop the disease in question.
For
example, women are generally felt to have a lifetime risk for major depressive disorder
of 10 to 25 percent (with men having approximately half that lifetime risk). Individuals
who have a first degree relative (parent, child, or sibling) with major depression
are thought to be 1½ to 3 times more likely to develop this disorder themselves
- which would bring the lifetime risk, for women, to somewhere in the neighborhood
of 50 percent. While having a close relative with depression by no means ensures that
one will develop depression, it clearly increases the likelihood.
As is
the case for all chronic diseases, it is useful to know one's family history with
regard to depression. This knowledge allows us to avoid additional risk factors (besides
family history, which we cannot avoid), and helps us to become more vigilant with
respect to early indications of disease onset.
With respect to additional
risk factors, individuals with a family history of depression may wish to avoid excessive
use of alcohol or exposure to psychoactive drugs - both of which activities are likely
to increase the chance of developing clinical depression.
Individuals
with a family history of depression should be especially attentive to periods of depressed
mood and to other symptoms commonly associated with clinical depression (e.g., suicidal
thinking, loss of interest in usual activities, feelings of worthlessness or guilt,
loss of energy, inability to concentrate, appetite changes, or sleep disturbance).
Those who notice such symptoms in themselves should consult their physician.
Chronic illnesses are, unfortunately, common. All of us have a family history for some of them. While this knowledge can be unsettling, it can also be empowering. Knowing your family history can help you to avoid risk factors that are within your control - and can also help you, in collaboration with your physician, to recognize and to treat illnesses more promptly. Diseases that are treated at an early stage can often be mitigated, such that they have a less severe course. This is true for depression as well: depression that is treated early is often less profound, and runs a shorter course, than depression treated at a later stage.