When Therese Borchard reflects on what caused the depression she’s wrestled with since the fourth grade, the 44-year-old Annapolis resident identifies two main factors: traumatic events that happened in her family, and a genetic predisposition toward depression and emotional sensitivity.
“My dad left when I was in the fifth grade,” says Borchard, who has written and blogged about mental illness—her own and in general—for years. “Before that, my mother would tell us he was on a ‘business trip,’ but then we would run into him at the store.”
On top of confusion and instability at home, depression ran in Borchard’s family; her mother experienced a deep depression after her father left, and her aunt committed suicide when Therese was 16. She recalls, “I am the most highly sensitive of my three sisters. For a deep feeler like me, I think the trauma at home was that much more difficult.”
Borchard’s experience is typical of what medical professionals call the “two-hit hypothesis” about the causes of depression: external events have a profound destabilizing impact on a developing teenager, and genetic and medical factors can determine a teen’s risk of experiencing clinical depression.
“Depression, like any mental illness, is a combination of genetic vulnerability and environmental contributions,” says Dr. Theodore Murray, medical director of Child and Adolescent Intensive Services at the Cambridge Health Alliance in Cambridge, Mass.
At any given time, he says, 10 to 15 percent—or 1 or 2 out of every 10 teens—may be depressed, whether or not they have officially been diagnosed. Exploring possible causes of a teen’s depression is an important step toward helping them get through an acute episode, and eventually recover.
External Events Can Have a Huge Impact
Environmental factors, external events that are out of the control of the teenager, are classic triggers for depressive episodes.
- They can involve everyday life, like learning difficulties at school or bullying by peers either at school or online.
- They can also be profound life experiences that would shake anyone’s emotional core, including parental divorce, sexual or physical assault, or the serious illness or death of a loved one.
- Even changes that have a positive impact on the family, like a move to a new home or school, impending graduation, or being selected for an advanced academic or athletic program, can be overwhelming to teenagers.
Research correlates other behavioral factors with depression as well. Nearly 30 percent of people who have substance abuse problems, for example, also have a diagnosis of major or clinical depression. Teens who smoke cigarettes are also more likely to exhibit symptoms of depression.
Genetic and Medical Factors Can Determine a Teen’s Depression Risk
The genetic component is no less significant. Teens with close family members who have suffered from depression are between two and six times more likely to experience depressive episodes themselves. And studies of identical twins as well as adoptive families have long suggested a genetic component to depression in teens.
Underlying medical conditions can also raise a teen’s risk of depression, which is why the diagnostic process pediatricians and mental-health professionals use should include a thorough medical exam. Murray lists these medical conditions as among those associated with an elevated depression risk:
- Thyroid disorders, both hypo – and hyperthyroidism
- Chronic inflammation, including Irritable Bowel Disorder
- Low vitamin D
How Important Is it to Identify the Causes of Depression?
Pinpointing the precise source of a teen’s depression can feel overwhelming to parents, but there’s no need for alarm if the cause is multi-dimensional and complicated, says Murray.
“Once someone hits the threshold for a diagnosis of major depression, it doesn’t matter that much how they got there,” he says. And, he adds, identifying a precise cause of depression does not dictate the course of treatment and does not impact the chances that any given treatment will be successful. A teen whose depression was triggered by the death of a parent, for example, is no more or less likely to improve after treatment than a teen whose depression seemed to come out of the blue.
However, when a painful or traumatic event happens in a family, there are steps parents can take to set a teen up for emotional success in a way that may mitigate the chances of a serious depressive episode, says Janet Lehman, the co-creator of The Total Transformation Program and a clinical social worker with 40 years of experience working with teens and families.
“Keep the lines of communication open” with teens during and after a difficult time, Lehman advises. That may mean doing more listening than talking, and not judging your teen for having complex, heavy, or lingering emotions. “Explain that it’s ok to feel a variety of emotions, and that this is actually healthy,” she says. “Let them know that whatever they have to say, you can handle it.” And remind them that you will help them connect with whatever outside support may be helpful in treating their depression.
More from Holly Lebowitz Rossi:
How Is Depression Diagnosed in Teens?