A little-known legacy of the Great Famine may be the exceptionally high levels of mental illness amongst later generations of Irish people, both at home and abroad, an Irish historian suggested last night.
Prof Oonagh Walsh told a Science Week event at IT Sligo she believed "epigenetic change" took place due to severe nutritional deprivation during the Famine, which claimed two million lives from 1845 to 1851.
Epigenetics is the study of changes in gene expression, that do not involve alterations to the genetic code or DNA, but whose effects may persist over several generations.
While still in the early stages of a study into the subject, Prof Walsh believes research will show a connection between high rates of mental illnesses and the effect of maternal starvation. She also believes there may be a connection between the Famine and the prevalence among Irish people of cardiovascular and other diseases.
Speaking before last night's lecture, Prof Walsh from Glasgow Caledonian University, pointed out that according to the 1841 census, when Ireland had a population of eight million, there were 1,600 inmates in district asylums, plus 1,500 in jails and workhouses.
By 1900, when the population had halved, there were 17,000 in district asylums and a further 8,000 “lunatics at large”.
She said there was no doubt the Dangerous Lunatic Act had been “abused on a staggering scale”, for example by emigrating families who did not want to bring along a relative who could be an economic burden.
There were other complex factors involved in committal rates but Prof Walsh said it was significant the exceptional rates of admission to asylums were also prevalent among Irish emigrants to for example Australia and Canada.
She estimated that the impact of the epigenetic change following the Famine lasted for a century and a half.