Depression has been shown to be passed down from parents to their children just as physical characteristics are. Research shows that multiple generations of families have grappled with the issues depression brings, including children and teenagers. Researchers are now looking at depression as a genetic risk factors, just as they look at heart disease and diabetes, proving that depression isn\u2019t entirely environmental. However, scientists have yet to locate the exact gene associated with depression. Some researchers are currently tracking the third generation of depression sufferers, calling the problem \u201chighly familial.\u201d Children of parents suffering from depression are up to three times more likely to experience it than kids whose parents do not suffer from depression. Worse yet, if the parent developed a mental illness before reaching their 20th birthday, the offspring of that parent are five to six times more likely to experience a mental illness of their own. Doctors are quick to point out that just because a teenager\u2019s grandparent suffered from depression doesn\u2019t mean they have a 100 percent chance of succumbing to it as well. But it also goes the other way: there is no assurance that a teenager with no family history of depression is 100 percent free and clear of risk. Scientists focused on early childhood depression, which would seem to have more biological factors than environmental, have identified several \u201cgenes of interest.\u201d But genetics might only be part of the equation. In the debate about nature and nurture, it would seem that both play a part in a teenager or child developing depression. The disorder is very complex and no two cases are exactly alike. There are roughly 15 million people in the U.S. battling major depression. Some of them turn to drugs and alcohol to alleviate their depression, which gradually makes everything worse. Many of these people are unaware that they are depressed, and many more don\u2019t know that there are likely people in their family who have undergone or are undergoing the same symptoms of hopelessness. Some researchers are noticing a pattern of anxiety in children who later develop depression. According to one researcher, one child with anxiety had major depression that peaked at age 15, and then again in their mid-30s. The anxiety manifests as a phobia prior to the pubescent years with depression setting in during adolescence. Males are more prone to combating their issues with substance abuse. Parents who know they have a family history of health issues, such as heart disease, are more likely to tailor the family diet around foods that help fight heart disease. Doctors are hoping parents with knowledge of a family history of anxiety and depression will be equally vigilant in their fight against the effects of depression.