Sadness, feeling down, having a loss of interest or pleasure in daily activities – these are symptoms familiar to all of us. But, if they persist and affect our life substantially, it may be depression. According to the Centers for Disease Control and Prevention (CDC), 7.6 percent of people over the age of 12 have depression in any 2-week period. This is substantial and shows the scale of the issue. According to the World Health Organization (WHO), depression is the most common illness worldwide and the leading cause of disability. They estimate that 350 million people are affected by depression, globally. Fast facts on depression: Depression seems to be more common among women than men. Symptoms include lack of joy and reduced interest in things that used to bring a person happiness. Life events, such as bereavement, produce mood changes that can usually be distinguished from the features of depression. The causes of depression are not fully understood but are likely to be a complex combination of genetic, biological, environmental, and psychosocial factors.