This year’s World Health Day on 7 April will be dedicated to the subject of depression.
The goal is to encourage sufferers to talk about their experience, and to seek help. Depression is often a hidden illness, but it can impact on people’s ability to carry out even simple tasks, and in the most serious cases, can lead to death by suicide.
"unresolved mental health problems lie at the heart of some of our greatest social challenges" (Duke and Duchess of Cambridge, and Prince Harry)
322 million people, or about 4.4% of the global population, were suffering from depression in 2015 according to the latest statistics from the World Health Organisation (WHO). The incidence was higher amongst women (5.1%) than men (3.6%), and older people were more susceptible than young people and children.
The total number of people living with depressive disorders has increased by 18.4% over the ten years since 2005, reflecting overall population growth, particularly in the most vulnerable age groups.
Similar trends are apparent for anxiety disorders, from which an estimated 264 million people, or 3.6% of the global population, were suffering in 2015, again predominantly women. This represents an increase of 14.9% over ten years.
Regional and national variations
Rates of depression and anxiety disorders vary considerably between countries and regions.
Within the WHO’s European region, in 2015 Ukraine had the highest percentage of its population suffering from a depressive disorder, at 6.3%, whilst Iceland and Kyrgyzstan had the lowest rates, at 4.1%.
In 2015, an estimated 788,000 died by committing suicide, although many more attempted to do so.
In that year, suicide became one of the 20 leading causes of death, accounting for nearly 1.5% of of the worldwide toll. Amongst 15-29 year-olds, it was the second most common cause of death.
Suicide rate varies by region and gender. For example, amongst females in the low- and middle-income countries of the Eastern Mediterranean and American regions, suicides are about 5 per 100,000 heads of population. However, amongst men in high-income countries, suicides occur at a rate as high as 20 per 100,000.
The WHO report defines depressive disorders as being:
characterized by sadness, loss of interest or pleasure, feelings of guilt or low self-worth, disturbed sleep or appetite, feelings of tiredness, and poor concentration. Depression can be long-lasting or recurrent, substantially impairing an individual’s ability to function at work or school or cope with daily life. At its most severe, depression can lead to suicide.
The report then goes on to identify the two main sub-categories: major depressive disorders, which are severe and intense; and dysthymia, which is a chronic form of mild depression.
Anxiety disorders are defined in the report as referring to:
a group of mental disorders characterized by feelings of anxiety and fear, including generalised anxiety disorder (GAD), panic disorder, phobias, social anxiety disorder, obsessive-compulsive disorder (OCD) and post-traumatic stress disorder (PTSD). As with depression, symptoms can range from mild to severe. The duration of symptoms typically experienced by people with anxiety disorders makes it more a chronic than episodic disorder.