One approach to improve the community functioning of patients with schizophrenia is to develop new agents that treat the cognitive deficits of the illness. A promising agent is called AL-108. This drug is administered as a nasal spray. Studies in animals suggest that this drug may protect neurons and may improve cognition in schizophrenia. The current study is a twelve-week multicenter, double-blind, randomized clinical trial of two doses of AL-108 (5 and 30 mg/day intranasally) versus placebo in the treatment of persistent cognitive dysfunction in schizophrenia. The study medication will be added to patients' current atypical antipsychotic medication or to their current injectable first-generation antipsychotic medication. The primary outcome measure will consist of the composite score of the MATRICS neuropsychological battery. Secondary outcome measures will include scores on symptoms, functional outcome, and safety measures. Sixty clinically stable patients with schizophrenia, drawn from eight sites, will participate in the study. Twenty-five patients will be enrolled at UCLA.