Scientists have discovered that the same part of the brain is responsible for the development of both schizophrenia and Alzheimer's – a finding that could help doctors predict who is most likely to suffer from the latter disease.
Schizophrenia tends to develop in adolescence or early adulthood, whereas Alzheimer's is a disease associated with ageing, but both involve a similar breakdown in brain function – intellectual capacity declines and long-term memory is reduced, among other effects.
As such, a connection between the two has been considered likely for a long time, but research published today by UK scientists in the journal PNAS offers the first evidence of a link. It turns out that having schizophrenia means you are more likely to have Alzheimer's later in life.
By carrying out MRI brain scans on 484 healthy volunteers aged between eight and 85, the scientists were able to study how the brain usually changes with age. They compared these with the scans of those suffering from schizophrenia and Alzheimer's, and found that a particular brain region was affected in both cases.
This region, rich in nerve cells, is well known for being related to intellectual ability. It is also the last part of the brain to develop in adulthood, as well as the first to degenerate in old age. It brings in information from the various senses, such as sight and sound, and coordinates it to help us understand what is going on around us.
Professor Hugh Perry from the Medical Research Council said: "Early doctors called schizophrenia 'premature dementia' but until now we had no clear evidence that the same parts of the brain might be associated with two such different diseases. This large-scale and detailed study provides an important, and previously missing, link between development, ageing and disease processes in the brain.
"It raises important issues about possible genetic and environmental factors that may occur in early life and then have lifelong consequences. The more we can find out about these very difficult disorders, the closer we will come to helping sufferers and their families."
While the scientists say more research is needed to say that there is definitely a link, the discovery will be a great help to doctors in terms of minimising risk of Alzheimer's in patients.
“Schizophrenia can be potentially devastating but at the moment it's very difficult to predict with certainty who is going to have a good prognosis and who might have a poor one,” said Dr Michael Bloomfield of University College London – one of the researchers involved in the study.
"This study brings us a step closer to being able to make this prediction, so patients could in the future receive better targeted treatments."