Lack of grey matter linked to schizophrenia and bipolar disorder

Jan 19 2009

A research study led by scientists from the Gregorio Marañón University Hospital in Madrid and the Network of Centres for Biomedical Research in Mental Health Networks (CIBERSAM) shows that adolescents experiencing a first outbreak of psychosis have lower levels of grey matter in their brains than healthy teenagers. Strangely, this change was seen in patients suffering from various psychoses, including bipolar illness and schizophrenia.

The objective of the study was to examine and locate differences in the volume of grey matter in the brains of healthy people (controls) and individuals diagnosed with psychotic outbreaks in infancy or adolescence. The researchers broke such psychosis down into three sub-groups - schizophrenia, bipolar disorder and other psychoses that did not fit into either of the other two classifications.

The study, published recently in the Journal of the American Academy of Child and Adolescent Psychiatry, analysed a sample of 121 people aged between 7 and 18, inclusive. All the patients and controls were examined using magnetic resonance imaging in order to detect any possible changes in the structure of their brains.

"The interesting thing was that we found common alterations among those with two types of clinically-differentiated psychoses, schizophrenia and bipolar disorder, and this could help to improve diagnosis of these illnesses," Santiago Reig, one of the study's authors and a researcher in the Medical Imaging Laboratory of the Gregorio Marañón Hospital, tells SINC.

The study confirmed these lower levels of grey matter, the brain substance in which neurone cells are concentrated. This lack, which was shared between the schizophrenia and type 1 bipolar illness sufferers, means the functions of this part of the brain are "somehow atrophied".

In addition, the technique used by the experts can pinpoint the location of these alterations. For example, "patients with early psychotic outbreaks (before the age of 18) showed alterations in the medial prefrontal gyrus region of the brain, which controls processes such as cognition and the regulation of sensations", says Reig.

Improving diagnosis

"Anything that helps to detect alterations shared between distinct pathologies can help in the development of drugs and in finding common characteristics between these different diseases," the researcher tells SINC. "Results like these are fundamental for the diagnosis and treatment of illnesses," he adds.

However, it is important not to draw any causal link between alterations in this area of the brain and the appearance of these pathologies. Psychiatric illnesses need more complex diagnosis. What the research does show, however, is that the majority of people with schizophrenia and type 1 bipolar illness do suffer from this lack of grey matter and the majority of healthy people have normal levels of this substance.

"We still do not know whether this loss of grey matter is caused by the illness or not," says Reig. This is just one more piece of the puzzle to help in understanding common features of psychiatric illnesses. "Maybe relating these developments with other new findings will one day help us to solve the riddle of psychiatric illnesses," he concludes.