The chief executive of the charity SANE has warned mental illnesses are still shrouded in stigmatism as new research reveals premature babies are more likely to develop psychiatric disorders.

Researchers at King’s College London found that babies born before 32 weeks were three times more likely to be hospitalised with a psychiatric disorder by the age of 16 than others.

The risk was higher for some disorders.

Premature babies were more than seven times more likely to develop bipolar disorder, which used to be known as manic depression, and 2.5 times more likely to be diagnosed with psychosis.

Marjorie Wallace, a Highgate Village resident and head of mental health charity SANE, said: “This may help throw light on the very dark area of the development of the brain, and why it is that some young people with the same stresses in life will be tipped over into serious mental illness and others are able to ride those storms.

“Certainly, it is quite extraordinary we don’t actually know what causes illness like schizophrenia, bipolar disorder or depression.”

Researchers believe the pattern is linked to changes in the development of the brain caused by injuries suffered at birth.

Previous studies had already established a link between schizophrenia and premature birth, but this is the first time a study has indicated a link with a broad range of psychiatric disorders.

Cautioning that the risk remains small, Ms Wallace said great strides had been made in the treatment of babies born early.

She said: “Mental illnesses still suffer form stigmatism. The way to reduce stigma is to find out why some people have a debilitating mental illness and help find ways of mastering their depression.”

A former investigative journalist, Ms Wallace’s groundbreaking articles into the schizophrenia prompted a massive outpouring of sympathy for those struggling with mental illness. She founded Sane shortly afterwards in 1986.

“When I originally wrote my articles I had to give everybody false names and everybody was photographed in the shadows as if they were in a world of crime or espionage,” said the Highgate resident.

“Now the papers are full of stories of people who have mental health problems. However, the stigma remains.

“It is very much like cancer was 40 years ago, when it was the ‘c-word’ and all cancers were treated the same and we whispered about it.

“I think it will remain until we find out more about what fuels mental illness and therefore more targeted treatment.”