Cognitive functioning in schizophrenia: A consensus statement on its role in the definition and evaluation of effective treatments for the illness

Background: Truly effective treatments for schizophrenia require much more than clinical efficacy. Symptom improvement is all that is required to demonstrate clinical efficacy. However, for a treatment to be effective in a wide-ranging manner, improvement in various life domains, such as social functioning, independent living, and employment, should also be found. Thus, a much wider range of improvements, not widely produced by previous treatments, is required to take treatment for schizophrenia to a new level of effectiveness. Consensus Process: A teleconference consensus meeting was held with the bylined authors on December 10, 2002, to explore the factors that hinder the most effective treatments for schizophrenia. We argue that a possible unifying factor underlying these apparently disparate domains of effective treatment is cognitive functioning, which is impaired in people with schizophrenia. Treatment of cognitive dysfunction may have a central role in increasing the breadth of effective treatment for schizophrenia. Conclusions: Novel antipsychotics and specific cognitive-enhancing medications have preliminarily been shown to have cognitive benefits that might lead to broader effectiveness of treatments, eventually reflected in improvements in the daily lives of patients. These treatments may have their greatest impact when combined with focused psychological interventions. While the research to date does not provide a large number of successes, this area will be one of considerable research interest for the next decade, with developments likely to be very important to clinicians treating patients with schizophrenia.