An important part of the effort to make a meaningful classification of schizophrenia subtypes is to identify common features that characterise a patient's neurocognitive functioning. Eugenia Kravariti of King's College London and colleagues recently studied more than one hundred people with a first episode of psychosis and several hundred healthy controls.

According to a publication in the October issue of the British Journal of Psychiatry, patients with schizophrenia appeared to perform worse on tasks testing executive function and processing speed. On the other hand, there were no differences between the two groups of study participants regarding visual and spatial perception or memory. According to the authors of the study, the appropriate bases for the classification of schizophrenia subtypes are the current value of a patient's intelligence quotient and whether it shows a decreasing trend.