In Post-World War II Britain, national records began to reveal a concerning trend. Deaths by suicide were rising in the war-battered nation, an increase that would continue from the end of the war into the early 1960s. Then, in 1963, that trend mysteriously reversed.

The graphs began to teeter downward. Experts puzzled over the reasons behind this drop in the suicide rate. Was it the birth of the Samaritans counselling services in 1953? Was it better psychiatric services offered under the National Health Service? But the reality turned out to be something entirely unexpected.

In the early 20th century, domestic gas that was used to warm British homes and cook people’s dinners was made almost entirely by heating coal, which created a gas mixture imbued with a hefty dose of carbon monoxide.

Consequently, ingestion of carbon monoxide poisoning from a gas oven became the most common method of suicide. In the early 1950s, new and cheaper methods of gas production were brought in – with a carbon monoxide content hovering near zero.

Suicides by domestic gas poisoning in the UK began to fall rapidly, bringing down the national suicide rate. Between 1963 and 1970, deaths by suicide fell by a quarter. By 1975, suicides by gas poisoning had pretty much disappeared. The experts were not quite sure what to make of this; could it really be that simple? A 1976 paper on the topic pondered how “the removal of a single agent of self-destruction can have had such far-reaching consequences.”

This question gets to the heart of what’s called “means restriction” – reducing access to methods people use to take their lives. Across the world, means restriction has had a huge impact. Over the past three decades, suicide rates have slowly and steadily dropped; between 2000 and 2016, the global mortality rate from suicide dropped by about 33 percent.

So, while it may feel like the world is crumbling into a war-torn, authoritarian shit show ravaged by rising temperatures and politicians who stand idly by, we can take solace in knowing that we’ve become better at preventing suicides.

It’s worth noting that all suicide numbers should be taken with a hefty grain of salt. Many countries underreport suicide deaths – due to data lags, as well as reasons related to stigma and religion. In some countries, suicide is still illegal. Nevertheless, it’s worth looking at the downward trend to see what lessons it can impart.

A big chunk of that decrease can be attributed to suicide declines in the two most populous countries in the world. Between 1990 and 2016, suicide rates decreased by 15 per cent in India and by over 60 per cent in China. A fast-growing Chinese economy resulted in far more people moving from the countryside to more urban areas. This meant that, in addition to more economic stability, they had reduced access to pesticides, a common means of suicide in lower-income countries, especially among young women in rural areas.

Banning or limiting access to dangerous pesticides has had astonishing effects in many other Asian countries too.

In 1995, Sri Lanka had the highest suicide rate in the world. The same year, it banned dangerous pesticides, and the national suicide rate has since fallen by 70 per cent. In Bangladesh, a similar ban led to a 65 per cent reduction. Elsewhere, means restriction methods such as barriers on high structures, gun control laws, and smaller medication packet sizes have been shown to considerably reduce suicide rates.

Means restriction works in part because suicide is often an unplanned act. The time between a suicidal impulse arising and a person acting on that impulse can be as little as five minutes. A person who dies by suicide has traditionally been represented as someone at the end of a long, tortured battle with depression, but this is generally not the case.

While having a mental illness is a strong predictor of suicide risk, most people with mental illness will never attempt suicide.

Reducing access to means allows time for the impulse to pass, and the person may never want to try again. One study found that only about 7 per cent of people who attempted suicide went on to take their own lives within the following five years.

Suicides aren’t evenly distributed around the world. According to the World Health Organization’s most recent estimates, nearly 80 per cent of suicides occur in low- and middle-income countries, where most of the world’s population lives, but high-income countries tend to have higher suicide rates.

The general global decline in suicides also hides pockets of the world where rates are climbing – countries like Zimbabwe, Jamaica, South Korea, and Cameroon.

One high-income country is a particular exception to the downward trend: the US. Although rates in the country declined throughout the 1990s, at the turn of the century they began to rise again. Between 2000 and 2018, the suicide rate jumped 35 per cent. Suicide is the second-highest cause of death among young Americans aged 1-14 and 20-35 years old.

You might be shouting: The answer is guns! And you’d be mostly right. In the US, over half of all gun deaths are suicides. In 2021 alone, over 26,000 people died by suicide using a firearm, out of the just over 48,000 recorded suicide deaths in total.

Research has found that the states with higher rates of household gun ownership also have significantly higher suicide rates. Limiting gun access remains the “most important actionable public health target for firearm suicide prevention efforts,” according to a 2022 paper looking at the country’s climbing suicide rate.

Suicides linked to guns are “totally preventable,” says Alexis Palfreyman, an honorary research fellow at University College London who researches mental health, suicidology, violence and sexual and reproductive health and rights. She points to Brazil, which enacted firearms restrictions in 2003, including making it illegal to carry or own an unregistered gun, raising the minimum age for purchase to 25 years old, and instituting background checks for purchase. It led to a 27 per cent reduction in firearm suicides.

“It’s just such a shame that we don’t seem to think that it’s worth the lives saved to actually do it,” Palfreyman says of the US.

Other factors may be contributing to rising suicide rates in the US, including structural racism, financial strain (driven by income inequality, personal debt and unemployment, to name but a few issues), the opioid epidemic, and a societal structure that features significant social isolation. Mental health disorders on the whole are on the rise in the US, which may also help explain the trend. But with firearms involved in over half of suicides, it’s impossible to deny that guns are playing an outsize role.

• A Wire report