Depression is the most common disorder in America that affects 19 million people around the country among all age groups. The number of patients with major depressive disorder has shot up over the past few years, worrying researchers and psychiatrists around the world. Depression can manifest in many different types, with common symptoms like an overwhelming feeling of sadness and hopelessness, loss of energy, and enthusiasm to name but a few.
While there can be many causes of depression, one of the biggest ones is genetics. However, several lifestyle and environmental factors can also influence the risk of developing the disorder. While there's no specific gene that determines your risk of developing depression, scientists have found several genetic sequences that play a role. If your biological parents or siblings have a history of depression, you might also be at risk. An average person has a 10 percent risk of developing depression at some point in their lives, depending on various environmental factors. But this risk can increase to 30 percent depending on your genetic makeup.
Other Factors That Contribute to Depression
While your genetic makeup is crucial for determining the risk of depression, just because you've inherited a few unlucky genes from your parents doesn't mean that you've gotten the short end of the stick. If you've been brought up in a healthy home under favorable environmental conditions, you're less likely to develop a mental disorder. On the other hand, some extreme environmental factors can increase this risk despite a person's genetic makeup.
A 2015 study showed that 76 percent of the participants with depression had suffered trauma in their past. Similarly, another study reported that people with a history of substance abuse with also more likely to struggle with some form of depressive disorder. Other environmental factors such as social isolation and financial stress can also lead to depression.
Several Studies Were Conducted
"We know that there are genetic factors, it seems to be heritable, but we also know there are a lot of other factors involved," says Renee Witlen, MD, a psychiatrist in Portland, Maine. Twin studies have been a useful method for researchers to investigate how much of a role heritability plays in the development of depression. Heritability refers to how much your genes account for different traits. Twin studies are often used because identical twins have the same genes, eliminating genes as a variable.
A 2009 twin study in the University of Washington Twin Registry estimated the heritability of depression to be at 58% among 1,064 female twin pairs. Another 2006 study of twins in Sweden published in the American Journal of Psychiatry found that the heritability of major depression was 42% in women and 29% in men, suggesting that some genetic risk factors may be specific to sex.
Risk Factors for Depression
Witlen says the cause of depression is multifactorial, so while your genes may increase your risk of developing genetics, they aren't the end-all.
Environmental and lifestyle factors can also contribute to depression. For example, Witten says the following can increase your risk:
Trauma - A 2015 study looked at 349 chronically depressed patients and found that 76% reported childhood trauma — including sexual, physical, or emotional abuse.
Substance abuse - According to a 2009 meta-analysis in the Journal of Substance Abuse Treatment, nearly half of women and a quarter of men with alcohol use disorder also struggle with major depression.
Social isolation - A 2017 study published in the Public Library of Science of nearly 2,000 adults found that those who felt more socially isolated were also more depressed.
Financial concern - Stress about money, such as worrying about being able to pay bills, having large amounts of debt, or even filing for bankruptcy can contribute to depression. A survey from the CDC found that depression in adults decreases as income increases.
In addition, certain types of depression have a specific trigger. If you think you are suffering from depression, you should try and talk to a therapist before it's too late. Only a certified and experienced mental health counselor would be able to tell you the exact reason behind your depression. Your therapist might advise you to take a sabbatical from work, stop worrying about something which you cannot change or control, or take anti-depressant medication. It depends. Do not hesitate to call 911 if you feel terribly depressed and have suicidal tendencies.
