With the help of MRI, researchers have found that antipsychotic drugs contribute to a subtle but measurable amount of brain tissue loss over time in patients with schizophrenia, according to study published in the February issue of the Archives of General Psychiatry.
Researchers at the University of Iowa Carver College of Medicine in Iowa City, led by Beng-Choon Ho, suggest the results show the importance of a risk-benefit review of dosage and duration of treatment as well as off-label use of antipsychotics (Arch Gen Psychiatry, Vol. 68:2, pp. 128-137).
The study evaluated four potential predictors of brain volume change: illness duration, antipsychotic treatment, illness severity, and substance abuse. Ho and colleagues noted that progressive brain volume changes in schizophrenia are thought to be due principally to the disease. However, recent animal studies indicate that antipsychotics, which are used to treat schizophrenia patients, also may contribute to decreases in brain tissue volume.
"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," they wrote.
Neuroimaging scans of 211 patients with schizophrenia produced 674 high-resolution MR images, with an average of three scans per patient over 7.2 years (up to 14 years).
The analysis found that longer follow-up correlated with smaller brain tissue volumes and larger cerebrospinal fluid volumes. In addition, greater intensity of antipsychotic treatment was associated with indicators of generalized and specific brain tissue reduction after controlling for effects of the other three predictors.
More antipsychotic treatment also was associated with smaller gray-matter volumes, and progressive decrement in white-matter volume was most evident among patients who received more antipsychotic treatment.
Illness severity had relatively modest correlations with tissue volume reduction, and alcohol and illicit drug misuse had no significant associations when effects of the other variables were adjusted, according to the researchers.
By Wayne Forrest
AuntMinnie.com staff writer
February 9, 2011
