U. IOWA (US) — Loss of brain tissue that at times occurs in patients with schizophrenia may be accelerated by antipsychotic medication commonly used to treat the condition.
The findings, published in the journal Archives of General Psychiatry, suggest that physicians should use the lowest effective dose of antipsychotics when treating patients.
The study does not recommend that patients with schizophrenia should not be treated with antipsychotic medications.
“Antipsychotic medications are still the most important and effective form of treatment for schizophrenia patients,” says Beng-Choon Ho, associate professor of psychiatry at the University of Iowa and the study’s lead author.
“These medications reduce psychiatric symptoms and prevent relapse in patients. What our study suggests is that careful review of risks and benefits of dosage and duration is very important.”
Schizophrenia affects 1 percent of the world’s population and is a leading cause of chronic disability among young adults. On average, progressive loss of brain tissue occurs at a faster rate in patients with schizophrenia than in normal comparison groups.
It has been assumed that brain volume reduction in schizophrenia is mostly a consequence of the disease process. However, animal studies have shown that antipsychotic treatment can reduce brain volume.
To investigate what factors may contribute to progressive brain volume reductions after illness onset, researchers studied serial MRI brain scans of 211 patients with schizophrenia starting soon after the patients were diagnosed. Each patient had, on average, three scans and was followed for an average of seven years.
The study examined the relationships between changes in the volume of gray matter and white matter in the patients’ brains and four potential contributing factors—illness duration, the amount of antipsychotic treatment, illness severity, and alcohol or illicit drug use.
“The main finding is that more antipsychotic treatment is associated with smaller volumes of gray matter and with greater reductions in white matter volume over time,” Ho says.
The researchers also found that these relationships between more antipsychotic treatment and reduced brain volume were still present even after the effects of the other three factors were taken into account.
In addition to their use in schizophrenia, antipsychotic medications also are increasingly used to treat other conditions, including depression and bipolar disorder, and in managing behavioral disorders in children and elderly individuals.
The study findings raise the possibility that reduction in brain volume could be a potential effect when antipsychotic drugs are used to treat these conditions.
“We do not know if antipsychotics are related to brain volume reductions in other patients receiving antipsychotic treatment,” Ho says. “Clinicians and patients with other mental conditions should review the benefits and potential risks of antipsychotic treatment.”
The study was funded in part by grants from the National Institute of Mental Health.
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