Over 350 million people are affected by depression worldwide, but despite the prevalence of this disease, it remains poorly understood.
Past studies have attributed it to a chemical imbalance in the brain, specifically, a lack of serotonin, which is often referred to as the 'feel-good' chemical. But this view does little to capture the entire, very complex basis of depression, because recent research has found that brain cell growth and connections are also playing a significant role.
And while external influences such as stressful life events have been proven to affect a person's risk of developing depression, the way you were born can also increase your chances. Recent research has identified a variation in the serotonin transporter gene as being linked to a higher risk, and many other genes are now being investigated as potential factors.
Watch the latest episode of AsapSCIENCE above to find out more about the science of depression.