"In the 1980s cocaine and heroin were widely used on Wall Street," says Dr. Alden Cass, a US psychologist who makes a living counselling dysfunctional bankers. "Now that drugs can be purchased over the internet, it's much more about prescription medications."

Cass says bankers' concoctions of choice include Adderall, a stimulant prescribed to people with attention deficit disorder. On one hand, it "gives them focus and energy and revs them up." On the other, says Cass, "it's addictive and if you have underlying heart problems it can cause heart attacks."

Another favourite is Vicodin, an opiate prescribed for people with back problems: "They use it to numb themselves from the stresses of a job in which they are constantly expected to perform," Cass adds.

Cass is keen to point out that prescription drug abuse isn't restricted to bankers: it's a phenomenon that he compares to doping in sports and he says it's prevalent in all well-paid stressful, performance-focused jobs in which job security is based on a daily need to perform – including law and the entertainment industry.

Due to the pernicious side effects of controlled substances, Cass advises people to develop other coping mechanisms instead. "The first goal is figuring out how to be efficient and have the natural energy to get through the work day," he says. "You need to sleep enough, eat right and be prepared from a scheduling standpoint, so that you know what needs prioritising. Adderall might help you get through the day, but it's not going to do you any good."