How common is clinical depression?
Nobody is sure exactly how many people are affected by depression. Health authorities from country to country and even within the same nation publish different figures:
The National Institute of Mental Health2 estimates that 6.7% of American adults have had depressive illness during the last 12 months, and 30.4% of these cases (2% of the whole adult population) have severe symptoms.
While the National Institute of Mental Health2 says women are 70% more likely to develop depressive symptoms during their lifetime, an article published in JAMA Psychiatry (August 2013 issue) showed that depression affects 30.6% of men and 33.3% of women, not a statistically significant difference.
The National Institute for Clinical Excellence (NICE)3 estimates that in the United Kingdom 21 in every 1,000 16-to-65 year olds live with major depression (17/1000 males and 25/1000 females). If “mixed depression and anxiety”, a less specific and broader category is included, the prevalence rises to 98 per 1,000.
In Australia only 1 in every five people with clinical depression is accurately diagnosed, according to the State Government of Victoria4, “because depression can mask itself as a physical illness like chronic pain, sleeplessness or fatigue.”