One person in the world dies by suicide every 40 seconds, according to the first ever comprehensive report on the issue from the World Health Organisation, which talks of a massive toll of tragic and preventable deaths.

Suicide rates vary enormously from one country to another around the world – influenced by the cultural, social, religious and economic environments in which people live and sometimes want to stop living. Some of the worst affected countries have more than 40 times more suicides than the least affected areas. But the pressures that cause extreme emotional distress are similar everywhere and there are measures all governments can take to make suicide less likely, says the WHO.

Overall, the Geneva-based UN body estimates that there are at least 800,000 suicides a year. But many countries do not collect good data, there is huge stigma and in a handful of nations suicide is still illegal, so it is highly likely the numbers are an underestimate. Criminalising suicide does not prevent it – India, where it is illegal, has one of the higher suicide rates in the world at almost 21 deaths per 100,000 people against a global average of 11.

Suicide map web

Suicide is the second leading cause of death among young people aged 15-29, but otherwise suicide rates increase in people older than 50. It is more common in men than in women, although the disparity is greater in rich countries than in poorer ones. Three-quarters of suicides occur in low- and middle-income countries, with higher numbers in central and eastern Europe and in Asia. North Korea has the very high suicide rate of 39.5 per 100,000 people, but South Korea's is almost as high, at 36.6. Catholic countries and those with large numbers of Muslims tend to have lower rates because of the opposition to suicide of their religion. People experiencing conflict, abuse and isolation and those suffering discrimination, such as refugees, migrants and those suffering prejudice because of their sexuality are all at increased risk.

For every death, there are many more people who try to kill themselves. Having attempted suicide is the biggest risk factor for dying by suicide at some point in the future. It is a clear cry for help, which governments are urged to pick up on.

Whether it is a mental health crisis, financial desperation, the death of a child or the breakdown of a relationship that triggers the thought of suicide, there is still often an opportunity to stop it, says the WHO.

WHO World Suicide chart1

"Suicidal tendencies are transitory," said Dr Shekhar Saxena, director of the department of mental health and substance abuse at the WHO and an author of the report. "People who have an intense desire to commit suicide grab the nearest possible means. If you can restrict their access even for a few hours, you can save a lot of lives. People think about it and talk to people and decide not to do it."

Most suicides take place in the early morning, perhaps after a sleepless night and before there is anybody around to talk to, or late at night when alcohol may play a part. Nearly one third of people who kill themselves use agricultural pesticides. These are usually farmers in low-income rural areas, who may be facing a loan they cannot repay after a bad harvest. They may have pesticide in a bottle on a shelf in the kitchen. WHO is encouraging governments to take steps to make it much harder for people to obtain such toxic substances.

"In India and Sri Lanka they have community storage of pesticides. There is a place where pesticides are stored under lock and key and people take them out when they need them – or you have storage in farms in a cupboard opened by two keys kept by separate people," said Saxena. Better still would be the use of other means than chemicals to control pests.

WHO World Suicide chart2

Other measures to prevent people easily getting access to the means of killing themselves have been adopted in other countries. Painkillers can only now be bought over the counter in limited quantities in the UK, for instance. Some bridges have high fences. Where guns are legal and easily obtained as in the US, the suicide rate is high and firearms are the leading means, adding to the arguments for gun control.

The WHO wants all countries to have a national suicide prevention strategy, which must include reducing access to the means of suicide. Also important are responsible reporting of suicides by the media to avoid the risk of inspiring copycat attempts, alcohol policies, care for people suffering from mental and substance use disorders, chronic pain and emotional distress and the training of health workers in assessing and managing suicidal behaviour.

Only 28 countries say they have a national suicide prevention strategy at the current time.

• If you are having suicidal thoughts, please contact the Samaritans on 08457 90 90 90. 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.