First his fingers, forearms and toes tingled; then he was gripped by a mental paralysis. “I couldn’t think about how to make a decision,” says the banking executive in his mid-forties. “I completely froze. I felt my IQ had dropped 50 points.” The trigger for his anxiety, he says, was unrealistic work demands. “Not making decisions made it worse as I was then not performing.”

Yet this City worker , who prefers not to be named, tried to conceal his anxiety because he feared his employer would think he was not cut out for the job. The prevailing culture at his office was to keep your head down, work hard, admit no weakness. He wanted to be seen as efficient and resilient. People noticed that his work — rather than his mental health — was suffering. “Given that I have always been pretty much the ‘golden boy’, when my boss took me to task I imploded.”

Plagued by a fear that he was a fraud he considered suicide. That was in 2014.

After receiving psychiatric help he is now back at work and has become an expert atspotting the signs of anxiety in others. “The characteristics that contribute to stress can also be the reason high achievers have reached their positions — people pleasing, perfectionism, the need to be strong and to be hyper vigilant to emerging threats,” he says.

His case is a stark example of the anxiety and stress that employees experience, and employers are increasingly having to pay attention to. It is a global phenomenon, but in the UK alone the most recent report from the chief medical officer estimates that the number of sick days lost to “stress, depression and anxiety” increased by 24 per cent between 2009 and 2013. The statistics are alarming: one report from Rotman School of Management in Toronto, published this year shows that 41 per cent of employees from a range of industries reported high levels of anxiety .

The increase is often blamed on modern working life. The constant buzz of texts, emails and tweets mangles our brains and stalks our sleep; robots are in the ascendancy, threatening to steal our jobs. New technologies emerge from left-field to flatten established companies; work appears insecure, corporate ties loose. And expectations of professional life have changed. Work, once the activity we did for money and status, is now supposed to provide personal fulfilment. The upshot? We are afflicted with unease, fear and worry.

“After a decade of disruption, cutbacks and lay-offs, anxiety among employees is running very high,” says Bill George, a senior fellow at Harvard Business School.

The diagnosis

Anxiety is typically described as a feeling of unease, worry or fear. When it becomes acute the effects can be debilitating. Some people are more vulnerable to it than others, at different periods in their lives. It is not something we can ever wholly eliminate and it can, at times, be helpful in improving our performance. But too much and it can be corrosive, on occasion leading to alcohol and drug abuse.

Absenteeism is just one problem for employers. The loss of productivity — dubbed “presenteeism” — is another. This occurs when employees come to work but function below par because of ill health. Research suggests this trend predominantly affects white-collar workers and that the costs can be high. One report estimated that presenteeism, including all medical and mental health issues, shaved 2.7 per cent off Australia’s gross domestic product in 2010. A study in the Journal of Applied Psychology, published earlier this year, reported: “Anxiety interferes with people’s ability to process immediate events, resulting in lower performance.”

In response, companies are introducing programmes to help workers cope better with stress and anxiety. Even in hyper-competitive industries such as finance or technology, there is increased understanding that attending to their employees’mental wellbeing may be good for profits.

The causes

Michael Sinclair, a psychologist in the City of London, sees a “tremendous” number of bankers and lawyers with work-induced anxiety. “They work at a relentless pace,” he says. “The pressure is always on and there is a culture of incessant email communication.”

But he also believes there is a bigger problem for companies: such anxiety can be infectious. “A company’s fear of failure breeds the same fear among its employees creating a ‘company sickness’ and culture of anxiety,” says Dr Sinclair. “Ironically this backfires and impacts the bottom line.”

Technology is a contributing factor, says Nigel Jones, a lawyer and co-founder of the City Mental Health Alliance, a non-profit organisation for London’s financial services workers. He believes the intensity has increased since he started work 30 years ago.

“Clients want more in terms of speed, quality. There is more pressure at work and the risk of anxiety is higher,” he says, adding that 27 City employers have become members of the network within two years. “Expectations of a speedy response [to a client] have got higher but the expectations of the quality of work have not gone down.”

Gianpiero Petriglieri, associate professor of organisational behaviour at Insead Business School, sees the rise of social media as triggering what has become known as “presentation anxiety”, making people feel vulnerable. We suffer from “being always on”, he says.

Although unemployment in the UK is at a seven-year low, short-term contracts and overall job insecurity have risen for millions of people, from steelworkers to nurses and bankers.

Some argue that it is impossible to calculate the impact of changing technology and employment conditions on the rise in reported cases of anxiety.

“Trying to directly compare levels of anxiety between eras is a fool’s errand,” says Scott Stossel, author of My Age of Anxiety. “Modern poll data and statistics about rising and falling levels of tranquilliser [use] aside, there is no magical anxiety meter that can transcend the cultural particularities of place and time.”