['Several lines of evidence suggest that brain-derived neurotrophic factor (BDNF) plays a critical role in activity-dependent neuroplasticity underlying learning and memory in the hippocampus. Schizophrenia has a range of cognitive deficits that may evolve from decreased BDNF, and this study examines this association of BDNF with cognitive deficits in schizophrenia.', 'We recruited 251 chronic schizophrenic patients and 206 healthy control subjects and examined the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and serum BDNF in both groups. Schizophrenic symptoms were assessed using the Positive and Negative Syndrome Scale.', 'BDNF levels were significantly lower in patients than controls (p\u2009<\u20090.001). Cognitive scores on the RBANS and nearly all of its five subscales (all p\u2009<\u20090.001) except for the visuospatial/constructional index (p\u2009>\u20090.05) were significantly lower in schizophrenic patients than normal controls. For the patients, BDNF was positively associated with immediate memory in schizophrenia.'] Is low BDNF associated with cognitive impairment in chronic patients with schizophrenia?