Mental illness is “much more common” than previously thought, the Metro newspaper has reported.

The generally accepted statistic is that around one in four people experience mental illness every year.

However, a new study may have turned that figure on its head.  The Duke University in New Zealand found that the true figure could rise to as many as 80 per cent.

“Mental illnesses are so common that almost everyone will develop at least one diagnosable mental disorder at some point in their lives”, said researchers Aaron Reuben and Jonathan Schaefer.

“Most of these people will never receive treatment, and their relationships, job performance and life satisfaction will likely suffer.

“Meanwhile the few individuals who never seem to develop a disorder may offer psychology a new avenue of study, allowing researchers to ask what it takes to be abnormally, enduringly, mentally well.”

Of the 80 per cent of participants who experienced a mental health problem, just 17 per cent experienced an “enduring” illness.

The researchers used this evidence to suggest that many mental health problems are both short and treatable.

“If you ever develop a psychological disorder, many assume you will have it for life,” they said.

“The newest research suggests, for the most common psychological complaints, this is simply not true.”