Cognitive dysfunction in schizophrenia (SCZ) and Alzheimer's disease (AD) is a major driver of functional disability but is largely unresponsive to current therapeutics. Animal models of cognitive dysfunction relevant to both disorders suggest the alpha 7 nicotinic acetylcholine receptor (nAChR) may be a promising drug development target, with multiple clinical trials subsequently testing this hypothesis in individuals with SCZ and AD. However, the translational value of rodent cognitive tasks for predicting the overall efficacy of this therapeutic target in clinical trials is unknown. To Compare effect sizes between rodent and human studies, we searched PUbMed and the Cochrane Library for all randomized, placebo-controlled trials of compounds With pharmacological activity at the alpha 7 nAChR for treatment of cognitive dysfunction in SCZ and AD and identified 18 studies comprising 2670 subjects treated with eight different compounds acting as full or partial agonists. Cognitive outcomes were standardized, and random-effects meta-analyses revealed no statistically significant effects of alpha 7 nAChR agonists on overall cognition or any of eight cognitive subdomains When all doses were included (Range of all cognitive outcomes: Cohen's d = -0.077 to 0.12, negative favoring drug). In contrast, analysis of 29 rodent studies testing the same ca agonists revealed large effect sizes in multiple commonly used preclinical behavioral tests of cognition (Range: d = -1.18 to -0.73). Our results suggest that targeting the alpha 7 nAChR with agonists is not a robust treatment for cognitive dysfunction in SCZ or AD and necessitate a better understanding of the translational gap for therapeutics targeting the a7 nAChR. (C) 2017 Elsevier Inc. All rights reserved.