Antipsychotic drugs cause brain volume loss detected by MRI
Antipsychotics used to treat schizophrenia, bipolar disorder and depression are found to cause loss of brain volume, detected by researchers using MRI.
In a new study, researchers found loss of brain tissue associated with taking the drugs is small, but measurable over time.
The study, conducted by researchers at the University of Iowa Carver College of Medicine, Iowa City, looked at 211 patients diagnosed with schizophrenia, beginning shortly after diagnosis.
The researchers say the investigation was conducted because mouse studies show antipsychotics lead to brain loss, making it important to understand what the long-term effects of the drugs are in humans who are prescribed medications for long term treatment.
The authors write, "Because antipsychotics are prescribed for long periods for schizophrenia patients and have increasingly widespread use in other psychiatric disorders, it is imperative to determine their long-term effects on the human brain.”
For the study, researchers used MRI's to monitor brain volume in the patients who had an average of 3 scans over a seven year period. In the analysis, they assessed the effect of treatment, length of illness, substance abuse and severity of symptoms relative to brain volume loss.
In the final analysis, there was no association between illness severity and substance abuse, leading the researchers to conclude antipsychotic drugs and severity of illness were the main contributors.
The authors write, "Are antipsychotic-associated gray matter and white matter volume reductions ‘bad’ for patients?” They note losing brain volume is undesirable, but say the clinical question of whether the benefits outweigh the risks is unknown.
The researchers say, though there are unanswered questions, the findings point to the importance for clinicians to prescribe the lowest dose of antipsychotic medication possible. Past studies have found the medications might also raise the risk of heart disease.
A Stanford study also suggested many new generation antipsychotic medications lack evidence of any real benefit, are often used "off-label" and surpass other drugs in number of prescriptions written. Use of the drugs has also become more common among children who have behavioral issues.
“Antipsychotics are effective medications for reducing some of the target clinical symptoms of schizophrenia: psychotic symptoms. In medicine we are aware of many instances in which improving target symptoms worsens other symptoms,” the authors write. “It is possible that, although antipsychotics relieve psychosis and its attendant suffering, these drugs may not arrest the pathophysiologic processes underlying schizophrenia and may even aggravate progressive brain tissue volume reductions.”
Another concern is the increasing use of antipsychotic medications for treating disorders other than schizophrenia. The study found the drugs lead to brain volume loss that is "assumed to be undesirable".
Arch Gen Psychiatry. 2011;68:126-127 doi:10.1001/archgenpsychiatry.2010.187