Treatment with typical antipsychotic medications leads to changes in the anatomy of the brain (10/06/05)

The anterior cingulate gyrus (ACG) is part of the brain that belongs to a group of brain parts, collectively called the limbic system. The ACG and the rest of the limbic system are all involved in processes underlying cognitive functions, like memory and learning, and in emotional thinking and behavior. Research has also shown that abnormalities of the ACG may be involved in the pathophysiology of schizophrenia. However, magnetic resonance imaging studies (studies where advanced techniques are used to visualize and study the brain in living patients) of this region have been few and the results inconsistent. Many of the studies have not taken into considerations other factors that may also contribute to the disease development, for instance exposure to the antipsychotic medications that the patients are treated with.

The size and the way in which the ACG is built up and the clinical characteristics of this region were evaluated in a group consisting of 30 right-handed male patients with schizophrenia and a control group of healthy individuals. The patient group was specifically designed to provide reliable data in terms of differences such as severity of illness, duration of illness and exposure to typical antipsychotic medications.

The results show that the patient group had a significantly larger left ACG compared with the control subjects. The right ACG size did however not differ between groups. This increase in ACG size was correlated with exposure to typical antipsychotic medications. The studies showed that the greater the exposure to typical antipsychotic medications was, the greater was the size increase of the left ACG. No significant relationship between the anatomy of the ACG and duration of illness or severity of the patient’s symptoms were observed.

In summary, the size of the left anterior cingulate gyrus in schizophrenic patients is directly related to treatment with typical antipsychotic medications (the greater the exposure, the bigger the ACG) but not to other clinical factors, such as length of illness or how severe the symptoms are.

Kopelman A, Andreasen NC, Nopoulos P. Morphology of the anterior cingulate gyrus in patients with schizophrenia: relationship to typical neuroleptic exposure. Am J Psychiatry. 2005 Oct;162(10):1872-8.
ABSTRACT