A new brain imaging study from the Institute of Psychiatry shows for the first time that the thalamus, the brain's main sensory filter or 'hub', is smaller than normal from the earliest stages of schizophrenia. The findings, published in the American Journal of Psychiatry in January, may explain why people with schizophrenia experience confusion during their illness.
The thalamus is the area where information is received and relayed to other areas of the brain. It is of particular interest in schizophrenia because of the role it plays in processing information. The thalamus receives information via the senses, which is then filtered and passed to the correct regions of the brain for processing. People with schizophrenia often have difficulties in processing information properly and as a result may end up with an information overload in some areas of the brain.
This study, led by Dr Tonmoy Sharma, involved 67 participants: 38 were experiencing their first episode of psychosis and 29 were healthy volunteers. In contrast to other studies, thirteen of the people with schizophrenia had no or little experience of antipsychotic medication.
Magnetic resonance imaging (MRI) scans identified differences in the thalamus between the two groups. Previous MRI studies have identified several brain regions affected by schizophrenia, but the results in the thalamus have been inconclusive. This study finds that even in the earliest stages of schizophrenia the thalamus is smaller than in healthy people.
Dr Tonmoy Sharma said: "This study reveals that there is a fundamental problem in the hub of the brain. If you think of the brain in terms of networks, it is like making a phone call when the line is not connected properly, the call can't be made, or you may get through to the wrong person. It is the same in the brain. If there are problems with the connections, information will not be passed to the correct regions. The ability to filter and process information is vital for leading a normal life."
These findings, along with a recent study from Dr Sharma's team that showed people with schizophrenia have decreased grey matter at the earliest stages of the illness suggest a role for brain imaging in pinpointing warning signs of the illness and even preventing its development.
Reference: U.Ettinger, X Chitnis, V Kumari, D Fannon, A Sumich, S O'Ceallaigh, V Doku and T Sharma. Magnetic resonance imaging of the Thalamus in first episode psychosis. American Journal of Psychiatry 2001; 158 (1)
Notes to editors
The Institute of Psychiatry is based at the Maudsley Hospital and is part of King's College London.
For structural images of the brain, background to the study, information on schizophrenia and all other enquiries, please contact Dr Tonmoy Sharma: +44 77101 47555.
t.sharma@iop.kcl.ac.uk or Jessica Sheringham: + 44 7989 550491.
Journal
American Journal of Psychiatry