Scientists finally solve 75-year-old riddle of how controversial electric shock treatment can treat severe depression
Electro-convulsive therapy involves electric shock being passed through cortex of the brain
22:59 GMT, 19 March 2012
Scientists have finally discovered how one of psychiatry's most controversial treatments can help patients with severe depression.
Researchers at Aberdeen University have discovered that ECT – or electro-convulsive therapy – affects the way different parts of the brain
involved in depression 'communicate' with each other.
They found that the treatment appears to 'turn down'
an overactive connection between areas of the brain that control mood
and the parts responsible for thinking and concentrating.
The controversial ECT treatment was introduced in 1938 by an Italian neurologist Ugo Cerletti. A nurse is pictured using it on a patient in 1951
This stops the overwhelming impact
that depression has on sufferers' ability to enjoy normal life and carry
on with day-to-day activities.
This decrease in connectivity observed
after ECT treatment was accompanied by a significant improvement in the
patient's depressive symptoms.
The ECT treatment, which is 75-years-old, involves an electric shock being passed through the cortex of a severely-depressed patient to 'cure' them.
Its graphic portrayal in the 1975 film One Flew Over the Cuckoo's Next won Jack Nicholson an Oscar.
The controversial treatment was introduced in 1938 by an Italian neurologist Ugo Cerletti, who was allegedly inspired by watching pigs being stunned with electric shock before being butchered in Rome. The animals would go into seizures and fall down, making it easier to slit their throats.
At the time psychiatric orthodoxy held – wrongly – that schizophrenia and epilepsy were antagonistic and one could not exist in the presence of the other.
Deciding to try the stunning technique on his patients, Dr Cerletti found electric shocks to the head caused his most obsessive and difficult mental patients to become meek and manageable.
Scientists found the treatment 'turns down' an overactive connection between areas of the brain that control mood and the parts used for thinking
Later the treatment was found to be effective in treating severe depression but its mode of action has remained until now a complete mystery.
The study involved using MRI to scan the brains of nine severely depressed patients before and after ECT, and then applying entirely new and complex mathematical analysis to investigate brain connectivity.
Professor of Psychiatry at the university Ian Reid, who is also a consultant psychiatrist at the Royal Cornhill Hospital, Aberdeen, said: 'We believe we've solved a 70 year old therapeutic riddle.
'ECT is a controversial treatment, and one prominent criticism has been that it is not understood how it works and what it does to the brain.
'For all the debate surrounding ECT, it is one of the most effective treatments not just in psychiatry but in the whole of medicine, because 75 per cent to 85 per cent of patients recover from their symptoms.
'Over the last couple of years there has been an emerging new perspective on how depression affects the brain.
ECT's graphic portrayal in the 1975 film One Flew Over the Cuckoo's Next won Jack Nicholson an Oscar
'This theory has suggested a 'hyper-connection' between the areas of the brain involved in emotional processing and mood change and the parts of the brain involved in thinking and concentrating.
'Our key finding is that if you compare the connections in the brain before and after ECT, ECT reduces this 'hyper-connectivity'.
'For the first time we can point to something that ECT does in the brain that makes sense in the context of what we think is wrong in people who are depressed.'
Although ECT is extremely effective, it is only used on people who need treatment quickly: those who are very severely depressed, who are at risk from taking their own lives, and perhaps cannot look after themselves, or those who have not responded to other treatments.
Professor Reid said: 'The treatment can also affect memory, though for most patients this is short-lived.
'However if we understand more about how ECT works, we will be in a better position to replace it with something less invasive and more acceptable.
'At the moment only about 40 per cent of people with depression get better with treatment from their GP.
'Our findings may lead to new drug targets which match the effectiveness of ECT without an impact on memory.'
Professor Christian Schwarzbauer, chair in neuroimaging at Aberdeen, who devised the maths used to analyse the data, said: 'We were able to find out to what extent more than 25,000 different brain areas 'communicated' with each other.
'The method could be applied to a wide range of other brain disorders such as schizophrenia, autism, or dementia, and may lead to a better understanding of underlying disease mechanisms and the development of new diagnostic tools.'
The team's findings are published in the journal Proceedings of the National Academy of Sciences.