A large study funded by NIH's National Institute of Mental Health (NIMH) provides, for the first time, detailed information comparing the effectiveness and side effects of five medications - both new and older medications - that are currently used to treat people with schizophrenia.
Overall, the medications were comparably effective but were associated with high rates of discontinuation due to intolerable side effects or failure to adequately control symptoms. One new medication, olanzapine, was slightly better than the other drugs but also was associated with significant weight-gain and metabolic changes. Surprisingly, the older, less expensive medication used in the study generally performed as well as the newer medications. The study, which included more than 1,400 people, supplies important new information that will help doctors and patients choose the most appropriate medication according to the patients' individual needs. The study results are published in the September 22 issue of the New England Journal of Medicine.
"The study has vital public health implications because it provides doctors and patients with much-needed information comparing medication treatment options," said NIMH Director Thomas R. Insel, M.D. "It is the largest, longest, and most comprehensive independent trial ever done to examine existing therapies for this disease."
Schizophrenia, which affects 3.2 million Americans, is a chronic, recurrent mental illness, characterized by hallucinations, delusions, and disordered thinking. The medications used to treat the disorder are called antipsychotics. Previous studies have demonstrated that taking antipsychotic medication is far more effective than taking no medicine, and that taking it consistently is essential to the long-term treatment of this severe, disabling disorder. Although the medications alone are not sufficient to cure the disease, they are necessary to manage it.
In the CATIE (Clinical Antipsychotic Trials of Intervention Effectiveness) trial, researchers directly compared an older medication (perphenazine), available since the 1950s, to four newer medications (olanzapine, quetiapine, risperidone, and ziprasidone), introduced in the 1990s. The purpose of the study was to learn whether there are differences among the newer medications and whether the newer medications hold significant advantages over the older medications; these newer medications known as atypical antipsychotics, cost roughly 10 times as much as the older medications.
The size and scope of the trial, with more than 1,400 participants at 57 sites around the country, its 18-month duration, and its inclusion of a wide range of patients in a variety of treatment settings ensure that the findings are reliable and relevant to the 3.2 million Americans suffering from schizophrenia.