Cases of depression have ballooned almost 20% in a decade, making the debilitating disorder the leading cause of disability worldwide, the World Health Organization (WHO) has said.



By 2015, the number of people globally living with depression, according to a revised definition, had reached 322m, up 18.4% since 2005, the UN agency said on Thursday.

“These new figures are a wake-up call for all countries to rethink their approaches to mental health and to treat it with the urgency that it deserves,” WHO chief Margaret Chan said.

According to the agency’s definition, depression is a “persistent sadness and a loss of interest in activities that people normally enjoy, accompanied by an inability to carry out daily activities for two weeks or more”.

Lack of energy, shifts in appetite or sleep patterns, substance abuse, anxiety, feelings of worthlessness and thoughts of self-harm or suicide are also common, and can affect entire families.

The drop in productivity, and other medical conditions often linked to depression, also takes a financial toll, with the global cost estimated at $1tn annually, the WHO said.

Shekhar Saxena, head of the agency’s mental health and substance abuse department, said both psychosocial and medical treatments could be highly effective, insisting on the importance of reaching more of those in need.

Even in the most developed countries, about half of people suffering from depression are not diagnosed or treated, and the percentage soars to between 80-90% in less developed nations.

Treatment can be difficult to access, while a fear of stigma also prevents many people from seeking the help required to live healthy and productive lives, the agency said.

According to the WHO, every dollar invested in improving access to treatment leads to a return of $4 in better health and productivity.

And “early identification and treatment of depression is a very effective means of decreasing death by suicide,” Saxena said.

There are about 800,000 suicides worldwide every year, amounting to one every four seconds. And the link to depression is clear.

Saxena pointed to studies showing that 70-80% of people who kill themselves in high-income countries, and around half of those in low-income countries, suffer from mental disorders, of which depression is the most common.

In the UK, the Samaritans can be contacted on 116 123. In the US, the National Suicide Prevention Hotline is 1-800-273-8255. In Australia, the crisis support service Lifeline is on 13 11 14. Hotlines in other countries can be found here