Does making suicide harder actually save lives?

The British gas story

Through the 1950s, most British homes ran on coal gas, and coal gas is full of carbon monoxide. Putting your head in the oven was the most common way people in Britain ended their lives. In 1963, domestic gas accounted for more than 40 per cent of suicides in England and Wales.

Over the next decade the gas supply changed, first to gas made from oil and then to natural gas from the North Sea. The reason was cost, not health. The new gas carried almost no carbon monoxide, and the oven stopped being lethal.

The psychiatrist Norman Kreitman tracked what followed. Suicide by domestic gas fell in every age group and in both sexes, in step with the fall in carbon monoxide. Suicide by other methods rose in some groups, most clearly in young people, but not by enough to make up the difference. The total suicide rate fell at every age. Kreitman concluded that neither better psychiatric care nor volunteer services could explain a change that size.

The criminologists Ronald Clarke and Pat Mayhew later put numbers on it. Between 1963 and 1975 the yearly count of suicides in England and Wales fell from 5,714 to 3,693, a drop of about a third, while suicide rose in most of Europe. Few of the people who lost the gas option found another way to die.

Why taking away one method works

The common belief runs: "If someone wants to die, they'll find a way." The gas data says that's usually wrong, and there are two reasons.

• Many suicidal crises are short. A study in Houston interviewed 153 people who survived nearly lethal attempts. For about one in four, less than five minutes passed between deciding and acting. A crisis that brief doesn't wait while the person hunts for another method.
• Methods differ hugely in how lethal they are. When people do switch, the second method is often less likely to kill them, so more survive and get a chance at help.

Surviving matters because most people who survive a crisis don't die by suicide later. In 1978 the researcher Richard Seiden followed up 515 people stopped from jumping off San Francisco's Golden Gate Bridge between 1937 and 1971. About 94 per cent were still alive, or had died of something other than suicide, years later.

The same pattern, again and again

What changed	Where	What happened
Coal gas replaced with low-carbon-monoxide gas	England and Wales, 1960s–70s	Total suicides fell by about a third
The most toxic pesticides banned, step by step to 1995	Sri Lanka	The suicide rate, which had risen eightfold since 1950, halved by 2005
Paracetamol sold in smaller packs (1998)	England and Wales	Deaths from paracetamol overdose fell by an estimated 43 per cent over the next 11 years
Barriers and nets at jumping sites	18 studies, several countries	Jumping suicides at those sites fell by 86 per cent

A review in The Lancet by Paul Yip and colleagues sums up the pattern: some people look for another method, many don't, and those who do tend to choose methods that kill fewer people.

What it doesn't mean

Restricting the means doesn't replace care. People in crisis still need someone to talk to, and treatment still helps. Means restriction buys time for those things to work.

It also isn't perfect. Kreitman saw suicide by other methods rise among young people, and barrier studies look hard for people moving to nearby sites. The finding is that total deaths fall, not that nobody ever substitutes.

Its strength is that it works for everyone at once. Nobody has to ask for help, be spotted, or get past stigma. The environment changes, and fewer people die.

What you can do at home

Most means restriction happens at home, not through laws.

• Clear out old medicines. Any Australian community pharmacy takes back unwanted or expired medicines for free and destroys them.
• Keep only what you need, and lock up the rest if someone in the house is struggling.
• Firearms: if someone is at risk, ask a trusted person to hold them, or store them locked away from ammunition, for now.
• Ask directly. "Are you thinking about suicide?" doesn't put the idea in anyone's head. It opens the door to help, and to a talk about making the house safer for a while.

Removing a lethal method during a hard patch can decide who is still here when the crisis passes.