Cognitive deficits in learning, memory, attention and decision-making represent chronically disabling aspects of many forms of mental illness, including schizophrenia. Age-related decline in cognitive abilities can also be debilitating to a substantial fraction of the human population. Cognitive dysfunction has been linked to deficient functioning of the hippocampal formation of the brain. The dentate gyrus, as part of the hippocampal formation, represents a site where new neurons are formed on a regular basis in the adult brain. Studies in laboratory mice have shown that the rate of new neuron formation in the dentate gyrus is stimulated by healthy activities such as wheel running, access to an enriched environment, and access to social interaction. It is hypothesized that pharmacological agents that specifically augment dentate gyrus-specific neurogenesis may benefit patients suffering from cognitive deficits. Over the past three years the investigators authoring this application have conducted an unbiased in vivo screen to identify drug-like chemicals capable of stimulating hippocampal neurogenesis. These efforts have led to the discovery of eight distinct, pro-neurogenic compounds. One of these compounds has been found to be orally bioavailable, endowed with a favorable half life, capable of crossing the blood brain barrier, and devoid of toxicity following multi-month administration at a level 10X the minimal therapeutic dose. Detailed studies have shown that this most advanced compound enhances both the birth and survival of hippocampal neurons. The putative efficacies of these eight compounds are being studied in an animal model of schizophrenia unique to the laboratory of the investigators. Likewise, biochemical methods will be employed to identify the molecular targets of as many of the eight pro-neurogenic compounds as possible. It is hoped that this work will provide a basis for the discovery of new treatment options for patients suffering from cognitive deficits associated with mental illness.