What destroyed the global economy? The financial sector's culture of moral flexibility, risk-taking and recreational drug use, says one academic.

AP / Steve Parsons/ PA Wire

The stereotype of a drug-fuelled banker has prevailed since the 1980s–an image of excess that goes hand in hand with a culture of risk-taking and endless evenings of entertaining clients. Now a leading British academic and former government drug-policy advisor has said that this very behavior may have caused the global financial meltdown.

David Nutt, professor of neuropharmacology at Imperial College, said in an interview with British newspaper the Sunday Times thatbankers “use cocaine and got us into this terrible mess.” The drug tends to make its users “overconfident” he said — which in turn leads them to taking more risks. “It’s a ‘more’ drug,” he added, which fits in with the financial industry’s “culture of excitement and drive and more and more and more.”

(MORE: The Cocaine Crisis: How the Drug Trade Is Ruining West Africa)

Nutt is no stranger to controversy—he was fired from his role as an advisor to the U.K. government in 2009 for arguing that ecstasy and LSD were less harmful than alcohol—but he is not the first to make a connection between recreational drug use among financial professionals and the crisis itself.

Chris Luke, an accident and emergency specialist based at Cork University Hospital in Ireland, said in 2010 that George W. Bush’s comments that “Wall Street got drunk” in reference to the financial crisis in 2008 was only half correct, claiming that Wall Street actually “got off its head” on cocaine:

“In financial centers and political centers the rampant use of cocaine lead to a kind of megalomania — a sense of master of the universe — which lead to what economists call irrational exuberance. People were making insane decisions and thinking they were 110% right, they could not be persuaded from that, which lead to the current chaos.”

There is some anecdotal evidence to suggest that drug abuse — in particular the use of cocaine and heroin — was and continues to be rampant among bankers. Take, for example, reports of brokers allegedly selling cocaine in exchange for insider information to claims that Bernie Madoff’s office was nicknamed “the North Pole” for the volume of cocaine allegedly consumed there. Hard facts about the rates of drug use among financial professionals remain rare, however.

(MORE: Sniffing Out a Line of Coke Brokers)

The UN World drug report from 2009 does indicate that in the run up the global financial crisis in 2008, British cocaine use peaked following a steady increase from the mid-1990s. Many scientists and rehabilitation-professionals have suggested that there is a higher level of use among some professions more than others — bankers being one of them.

Cocaine is known to cause an accumulation of dopamine in the brain – the feel-good chemical that is also linked to risk-taking. Users tend to feel incredibly confident and wide awake, but repeated use leads to agitated behavior, mood swings and severe addiction—traits that become manifest in other risk-taking activities such as betting on stocks.

Ironcially, drugs may have also helped the financial system endure the global financial crisis intact. Antonio Maria Costa, the United Nations’ drugs and crime czar, argued in 2009 that illicit drug money worth billions of dollars kept banks in Europe and the U.S. afloat during the global financial crisis.

MORE: Banker Angst, The Inside Story