Placebo response in schizophrenia trials seems to be increasing

Drugs used to treat schizophrenia are known as antipsychotics. For some people, the drugs can suppress symptoms like hallucinations and delusional thinking, and allow them to live a more normal life. Studies of existing schizophrenia drugs indicate that their beneficial effects are lessening because more patients are responding to inert placebos used for comparison.

Researchers at the Food and Drug Administration (FDA) looked at 32 clinical trials that were submitted to the agency between 1991 and 2008. The researchers found North American trials conducted in more recent years turned up smaller treatment effects than older studies. The trend is concerning, according to the FDA researchers, because clinical trials with big placebo responses are more likely to fail - meaning they don't show a statistically clear difference between the treated group and the placebo group.

Dr. Thomas P. Laughren, head of the FDA's division of psychiatry products says more research is needed to figure out what's really going on.

Physicians Postgraduate Press - Reuters US edition 2012