Antipsychotic drugs linked to slight decrease in brain volume

cjb250 — Fri, 18 Jul 2014 18:00:00 +0000

As we age, our brains naturally lose some of their volume – in other words, brain cells and connections. This process, known as atrophy, typically begins in our thirties and continues into old age. Researchers have known for some time that patients with schizophrenia lose brain volume at a faster rate than healthy individuals, though the reason why is unclear.

Now, in a study published in the open access journal PLOS ONE, a team of researchers from the ̽��ֱ�� of Oulu, Finland, and the ̽��ֱ�� of Cambridge has identified the rate of decrease in both healthy individuals and patients with schizophrenia. They also documented where in the brain schizophrenia patients have more atrophy, and have examined links between atrophy and antipsychotic medication.

By comparing brain scans of 33 patients with schizophrenia with 71 control subjects over a period of 9 years – from age 34 to 43 – the researchers were able to show that schizophrenia patients lost brain volume at a rate of 0.7% each year. ̽��ֱ��control participants lost brain volume at a rate of 0.5% per year.

Scientists have previously speculated that antipsychotic medication used to treat schizophrenia may be linked to this decrease in brain volume. Today’s research confirms this association, showing that the rate of decrease in volume was greater when the dose of medication was higher. However, the mechanisms behind this – and whether it was in fact the medication that was causing this greater loss of tissue – are not clear. Some researchers have previously argued that whilst older antipsychotic medications might cause brain volume decreases, newer antipsychotic medications may protect against these decreases. However, today’s research suggests that both classes of antipsychotic medication are associated with similar declines in brain volume.

̽��ֱ��researchers also looked at whether there was any link between the volume of brain lost and the severity of symptoms or loss of cognitive function, but found no effect.

Professor Juha Veijola from the Department of Psychiatry at the ̽��ֱ�� of Oulu, Finland says: “We all lose some brain tissue as we get older, but people with schizophrenia lose it at a faster rate. We’ve shown that this loss seems to be linked to the antipsychotic medication people are taking. Research like this where patients are studied for many years can help to develop guidelines about when clinicians can reduce the dosage of antipsychotic medication in the long term treatment of people with schizophrenia.”

“It’s important to stress that the loss of brain volume doesn’t appear to have any effect on people over the nine year follow-up we conducted, and patients should not stop their medication on the basis of this research, ” adds Dr Graham Murray from the Behavioural and Clinical Neuroscience Institute and the Department of Psychiatry at ̽��ֱ�� of Cambridge. “A key question in future will be to examine whether there is any effect of this loss of brain volume later in life. We need more research in larger studies with longer follow-ups to evaluate the significance of these brain changes.”

̽��ֱ��research was supported by the Academy of Finland, Medical Research Council, Sigrid Jusélius Foundation, and the Brain and Behavior Research Foundation.

A study published today has confirmed a link between antipsychotic medication and a slight, but measureable, decrease in brain volume in patients with schizophrenia. For the first time, researchers have been able to examine whether this decrease is harmful for patients’ cognitive function and symptoms, and noted that over a nine year follow-up, this decrease did not appear to have any effect.

̽��ֱ��loss of brain volume doesn’t appear to have any effect on people, and patients should not stop their medication on the basis of this research

Graham Murray

Adrian Cousins, Wellcome Images

Schizophrenia - hearing voices (Artist's illustration)

̽��ֱ��text in this work is licensed under a Creative Commons Licence. If you use this content on your site please link back to this page. For image rights, please see the credits associated with each individual image.

Yes

̽��ֱ�� of Cambridge - Brain and Behavior Research Foundation

Antipsychotic drugs linked to slight decrease in brain volume