CHRNA7 and Cognitive impairment: In 2021, a meta-analysis and systematic review of data from 13 randomized controlled trials in which α7nAChR agonists were added to antipsychotic treatment in patients diagnosed with schizophrenia spectrum disorder found no evidence in support of such regimens for the treatment of cognitive deficits, but there was a small effect in favor of the use of α7nAChR agonists for negative symptoms [81].