More than 100,000 people a year in England who are mired in heavy debt try to end their lives, new research has revealed.

Intimidating and threatening letters sent by debt collectors, bailiffs and councils raise the risk of suicide by adding to people’s feelings of despair, the study found. The findings have prompted calls from mental health experts for an urgent overhaul of the tactics banks, utility companies, credit card companies and others use to pursue people struggling to repay money they owe.

One in 14 adults is in problem debt, meaning they have fallen very behind on paying bills or credit agreements or have been cut off by a gas, electric or water supplier in the past year. They are three times more likely than the general population to have thought about ending their life, according to research undertaken by the National Centre for Social Research (NatCen), Britain’s largest independent social research body.

NatCen analysed detailed NHS data about adults’ mental health undertaken for the Money and Mental Health Policy Institute. It found that 13% of people in problem debt – about 420,000 a year – think about suicide and 4% of them – more than 100,000 people – try to end their life.

Martin Lewis, the personal finance expert who set up and chairs the institute, said letters to debtors, who can receive several a day, are so ruinous to mental health that they are pushing people to consider suicide. He urged ministers to amend the Consumer Credit Act 1974, which obliges those seeking to recover debts to use an array of formal language, which many find terrifying.

“The fact a law set decades ago doesn’t just allow companies to use intimidating language when collecting debt, but near forces them to do so, causes tragedy,” Lewis said. “The last thing those struggling with debts need is a bunch of near thuggish letters dropping through the letterbox, in a language you can’t understand, threatening you with court action.

“And with such a tight link between mental health and debt crisis, we know that many of the people receiving these letters are extremely vulnerable. These letters are destroying lives.”

Samaritans, Mind and the Royal College of Psychiatrists are among those backing the institute’s campaign, which aims to persuade the government to change the legislation so such letters are much less threatening to those receiving them.

The last thing those struggling with debts need is a bunch of near thuggish letters dropping through the letterbox Martin Lewis, finance expert

The pressures such letters can induce were highlighted by the case of Jerome Rogers, a 20-year-old courier who took his own life after bailiffs clamped his motorbike after two unpaid £65 fines for parking offences imposed by Camden council mushroomed to a debt of £1,019.

The institute’s report points out that the feelings often displayed by people who are thinking about suicide mirror the psychological responses of many people who end up in serious debt.

NatCen’s findings, based on its analysis of a huge NHS dataset called the adult psychiatric morbidity survey, also found that:

*People with multiple debts are five times more likely to have tried to kill themselves than those with one debt.

Almost a quarter (23%) of those who made a suicide attempt last year were in problem debt.

The “double stigma” around debt and suicide means many of those who are struggling do not tell anyone how they are feeling or seek help.

“This is harrowing new evidence that far from tackling the burning injustice of mental ill health, the actions of this government are pouring petrol on the flames”, said Barbara Keeley, the shadow minister for mental health.

“The continual rise in poverty, insecure work and the crisis of low pay brought on by the decision of this callous government to pursue austerity relentlessly is seeing shockingly high numbers of people in desperate straits attempt to take their own lives.”

Ged Flynn, the chief executive of the charity Papyrus, which tries to reduce youth suicide, said: “It is no surprise that debt may contribute to people’s thoughts of suicide in many cases. In young people, insecurity in employment, increasing and prohibitive rent, zero hours contracts and not being able to get on the housing ladder, often causing a downward spiral of debt, can make many young people experience despair.”

Vicki Nash, Mind’s head of policy and campaigns, said: “Behind these figures are real people – parents, children, siblings, colleagues and friends – whose lives are being devastated. Mind [has] found that half of people with mental health problems have thought about or attempted suicide as a result of social issues such as housing issues, debt, benefit support, and employment.”

A government spokesperson said: “Suicide is the most devastating outcome for people struggling with the challenges of life and we are committed to helping people in problem debt receive the proper support. We’ve increased funding for the Money Advice Service to over £56m, enough to help over 530,000 people get the debt advice they need.

“We’re also introducing a ‘breathing space’ from problem debt to give people time to get their financial lives back on track. Every suicide is a preventable death and we are working hard with our partners across government, businesses and communities to help tackle this problem.”

The institute wants banks, councils, utilities providers, public health teams and all credit providers to do much more to spot suicide risk in people in heavy debt, encourage them to talk about their situation and minimise the psychological harm involved.