A U.S. study suggested cognitive gains in schizophrenic patients treated with newer antipsychotic medications are due to practice effects, not the drugs.

   Second-generation antipsychotic medicines were designed to improve the speed, clarity, and rationality of thought among people with schizophrenia and other psychotic illnesses.

   But psychiatric researchers at the Zucker Hillside Hospital and the Feinstein Institute for Medical Research studied the cognitive performance of 104 people newly diagnosed with schizophrenia who were taking second-generation medicines.

   The medical scientists tracked those patients and 84 healthy, age-matched controls on 18 measures of thinking by asking them to take a series of cognitive tests three times during a four-month period. At the end of that time, the researchers found both the patients and the healthy controls showed the same cognitive gains.

   The study's lead author, Terry Goldberg, said: "It is a sobering finding (since) the field has just accepted that these medicines enhance cognition. But it may be that (patients are just) getting better at doing the same test over time.

   "If it's just a practice effect, it is a big problem," he added 
  The study appears in the Archives of General Psychiatry.

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